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Musings of an Energy Nerd

Deep Energy Retrofits Are Often Misguided

It’s time for energy retrofit specialists to overcome their prejudice against PV systems

Deep energy retrofit jobs are frighteningly expensive. The energy retrofit work at this house (61 Oakwood Avenue in Sudbury, Massachusetts) cost $241,000.
Image Credit: National Grid

All through the 1980s and 1990s, a small band of North American believers worked to maintain and expand our understanding of residential energy efficiency. These were the pioneers of the home performance field: blower-door experts, weatherization contractors, and “house as a system” trainers. At conferences like Affordable Comfort, they gathered to share their knowledge and lick their wounds.

These pioneers understood what was wrong with American houses: They leaked air; they were inadequately insulated; they had bad windows; and their duct systems were a disaster.

Occasionally, these energy nerds would scoff at millionaire clients who were more interested in “green bling” — a phrase that usually described photovoltaic panels — than they were in reducing air leaks in their home’s thermal envelope.

A shared belief

What I’ve just described is (in anthropological terms) a set of beliefs associated with a distinct subculture. Our tribe had a shared belief: that improving a home’s thermal envelope is preferable to installing renewable energy equipment.

Occasionally, a few facts would appear to undermine our belief system. For example, if a disinterested observer noted that a proposed envelope measure had a very long payback period, most members of our tribe would answer that the measure was a wise investment, because energy prices are likely to skyrocket in the future.

During the waning years of the last millennium, these North American beliefs crossed the Atlantic and were adopted by a group of academics in Darmstadt, Germany.

The beliefs became petrified in a set of rules called the Passivhaus standard.

Times have changed

Several factors have changed since these beliefs were first formulated. For one thing, fossil fuel prices have stayed low; for another, photovoltaic equipment has gotten dirt cheap.

The (sometimes painful) fact is that it is now hard to justify many energy-retrofit measures that…

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  1. dankolbert | | #1

    Well put
    !Viva the shallow energy retrofit! I too have heard Paul talk about his experience, and I think it jibes with mine. Do upgrades to systems (including wall sections and insulation) when components need to be replaced anyway, but tearing out serviceable material or equipment usually doesn't make sense.

    There are plenty of beat up, run down ranches with poured foundations - I think those are excellent candidates for DER's. Otherwise, it needs to be carefully thought through. As Paul & Mike argue, making a long-term plan for a house and making sure any work is in accordance with that plan makes more sense.

  2. GBA Editor
    Martin Holladay | | #2

    Response to Dan Kolbert
    That's a nice addition to our glossary. For new construction, the best approach is the Pretty Good House. For existing homes, the Shallow Energy Retrofit.

    Another term for the Shallow Energy Retrofit approach is "weatherization" -- a tried-and-true approach that emphasizes cost-effective measures.

  3. Aaron Birkland | | #3

    Upstate NY
    Upstate NY has a set of conditions that makes a DER look even worse on paper - low property values, high property taxes (especially as a percentage of home value), and lots of decaying old houses with deferred maintenance. I recall a similar blog post focusing on DER results in Utica, NY.

  4. Robert Swinburne | | #4

    Law of diminishing returns applies
    Well said and thank you for saying it. There is so much pressure to do deep energy retrofits as those are what gets published and win the awards. In my experience working with people who don't have 100k or more (most of my clients), the question isn't about payback but "what can we do to make you more comfortable in your home". Often simple "weatherization" goes a long way. A shallow energy retrofit can halve the oil bill and reduce the worry about frozen pipes, mold issues, uncomfortably cold and drafty rooms in the winter etc. If you have extra money for that additional 2" of insulation, perhaps it is a better idea to donate it to your local town's low income weatherization program.

  5. EnergySage | | #5

    Nice article!

    Thanks for using and crediting our image.

    If you're at all interested in going solar, you can get an instant estimate of your property's solar potential here -

  6. user-757117 | | #6

    Economics - law or "tribal belief system"?
    It sure seems like there is something inherently paradoxical about buying solar panels made cheap by economies of scale, which are themselves largely enabled through huge, dirty energy expenditures.

    And Eldrenkamp responded, “Right. And focus on occupant behavior. And then install PV.”

    Respectfully, I suggest that here is the elephant in the room.

  7. GBA Editor
    Martin Holladay | | #7

    Response to Lucas Durand
    Of course occupant behavior determines energy use. I've written about that topic several times (including in a 2012 article called Occupant Behavior Makes a Difference).

    But I don't think that the importance of occupant behavior invalidates the points I made in this article. It's not as if there is some form of occupant behavior that will ever make a deep-energy retrofit cost-effective.

  8. user-757117 | | #8

    Response to Martin
    Of course not.
    You began your article by issuing a call to the "tribe of energy nerds" to abandon their prejudices.
    Fair enough - never a bad time for some self-reflection.
    All I am saying is that there is a larger "tribal belief system" that is also badly in need of some self-reflection.

  9. GBA Editor
    Martin Holladay | | #9

    Response to Lucas Durand
    I agree. Unfortunately, if I tried to list all of the elements of our North American tribal belief system that are detrimental to a sustainable relationship with our natural environment, my hands would get weary and would fail me before I reached the end of the list.

  10. nick57 | | #10

    A thoughtout article. I agree
    A thoughtout article. I agree with the view about PV. On the other hand, I attended a Build America conference call last week in which the academic speakers presented evidence that basic energy retrofits had a reasonable return rate. Part of the question is how long of a payback period is reasonable? maybe we are holding these investments to a return period that is too short. First, most retrofits have a useful life approaching the life of the house-at least 30 years. Second, money is as cheap as it has ever been and true inflation (as opposed to the fake government statistics) is still high . With interest rates at historic lows, are alternative long term investments better? In light of Setroit, does a 30 year municipal bond at 4% make as much sense as an investmemnt in a retrofit with a 30 year useful life? Retrofits would be a safer economic bet if the home resale market recognized the value of future energy savings imbedded in a house with a retrofit, but that is where educating the public comes in (as would a few more winters like this or a future disruption in the energy markets).
    I do agree that for those most interested in reducing carbon emmissions (as opposed to an economic investment), a donation to Habitat to "winterize" homes in poor neighborhoods is a better approach.
    In my mind, the real issue with energy retrofits is whether it is healthy to zip up my family in a tight shell full of synthethic chemicals, even with mechaniccal air exchange.

  11. GBA Editor
    Martin Holladay | | #11

    Response to Nick DeFabrizio
    The approach you suggest -- calculating the cost-effectiveness of various energy retrofit measures, and choosing the measures that provide a reasonable rate of return -- is one commonly used by many programs, including the federal Weatherization Assistance Program.

    As generally understood, deep energy retrofits go much farther -- often aiming for R-40 walls, R-60 roofs, and new triple-glazed windows. These are the types of projects with price tags that exceed $100,000 per housing unit.

    You wrote, "The real issue with energy retrofits is whether it is healthy to zip up my family in a tight shell full of synthetic chemicals, even with mechanical air exchange." Done properly, an energy retrofit job should result in better indoor air quality, not worse. If your house is full of synthetic chemicals that worry you, it might be best to address those chemicals before settling on a weatherization plan. In any case, a properly designed mechanical ventilation system is usually preferable to random air leaks.

  12. Expert Member
    Dana Dorsett | | #12

    PV will soon be the cheapest energy of any type. So what?
    Yes net metering will change, but cheap batteries are coming fast on the heels of cheap PV. Grid defection is going to be a real possibility within 10 years, sooner if the utilities don't manage the tsunami of dirt-cheap PV before grid storage gets dirt cheap. If the net metering compensation becomes egregious it will invite mass grid defection- the tipping point on pricing is already pretty near at hand. These are clearly disruptive technologies that will change how the grid operates dramatically and permanently. Even the analysts at Morgan Stanley think so:

    The policy wonks at RMI think so too:

    Tesla's move in to large scale battery manufacturing, while interesting and useful (particularly from a transportation-electrification point of view), I'm skeptical that lithium-ion will dominate the grid storage game for long, if ever. The liquid-metal grid battery technology currently being commercialized by Ambri while less efficient than lithium ion in the AC-DC-AC turnaround (and way too low a power density to useful in cars even if the liquid sloshing issues could be tamed). The basic materials are ubiquitous & cheap, the capacity is easily scalable to the application, and the challenges for manufacturing are negligible. It's not a high-tech product requiring exotic equipment or processes, which makes me think AMBRI or other cheap-storage startups are more likely contenders for the grid storage market than Tesla's (or A123's) lithium ion batteries. (see )

    For those without access to sufficient sun grid defection en-masse would be an expensive disaster, as all of the maintenance costs of the grid would fall onto the remaining rate payers who still actually NEED the grid:

    While PV power may soon be cheap, it's real-estate limited. Even with space heating leveraged by heat pumps, the source the annual energy use of a IRC 2012 code min house totally with ~15-20% efficiency PV takes more area than the footprint of said house in all but a few areas of the US. Even with the most efficient inverters and a theoretical-maximum PV efficiency in the ~35% range that would still be true. There is still a case to be made for deep energy retrofits implemented on a least-cost basis (even when the cost of that last inch of foam has no "payback" on direct energy costs) to lower the cost of the grid-maintenance for the grid attached homes. But it won't be long before whole subdivisions are built with a localized privately held islanded grid with minimal or no connection to the larger power grid.

    Certainly from a policy point of view fixing the dead-obvious energy issues of inefficient legacy rental properties buys a heluva lot more carbon reduction than a $241K DER on a circa 1963 ~1400' house in a wealthy Massachusetts suburb:

    A DER on a 3-family rental property I was involved with a couple of years ago in central MA had fairly poor solar access, a combination of sub-optimal roof angles and shading factors of neighboring buildings & trees, and needed extensive repairs (a full-gut rehab.) The cost of the foam-over was dramatically reduced by extensive use of reclaimed roofing foam rather than virgin stock, and all DER measures combined came in WELL under the DER cost of that suburban house, even before the utility subsidies were applied.

    Doing the same rehab at code min the annual energy requirements could not have been met with a PV array the size of the entire urban plot, let alone on the roof of the house, but were the solar access factors better it clearly could. But the lifecycle cost, carbon reduction per dollar, and ROI of the DER in this instance is far better than the Sudbury single-family, and the cost/benefit of site-PV in this instance even at a buck-a-watt would not have been better than the "extra" 3 inches of (reclaimed) foam beyond a code-min assembly would not have been a better investment.

    I was originally brought into the project by the owner who wanted to know if solar-thermal could be added to this wreck " be nice to the future tenants". The answer was pretty obvious on the first site visit, but the opportunity to do a significant upgrade on the thermal performance of the building was just as obvious. Pushing him into the the subsidy money for the DER through the utility-funded program made it a no-brainer, not just a "be nice to the tenants" deal, since after subsidy the cost of the thermal fixes was dead-even with the cost of what would have been necessary to meet code min (IRC 2009, in this jurisdiction.)

    Whether that was the best investment in load reduction for the utility could be debated, but it's clearly not the worst, since the material cost of the reclaimed foam was less than 1/3 that of virgin-stock, and it would have needed an inch to hit code-min, which clearly IS cost effective on a lifecycle basis even using virgin-stock foam.

    Bottom line, there are lots of ways to skin a cat, and lots of cats to skin. Deep energy retrofits are one, and will sometimes be appropriate, even in the era of dirt-cheap solar.

  13. wjrobinson | | #13

    I feel like i just experienced seeing someone surprise a flock of turkeys... birds a flight every which way... and then that's it, one roosting here, one there... me... jaw dropped... neat experience.

    In the end, it's all about the money. Aaron's point is very valid here in the ADKs.

  14. RAHra | | #14

    DER's - PR's low hanging fruit
    As someone noted, DER's can get published, written up in the news, maybe even a 10 sec bite in the local news show.
    Blowing insulation into the walls and roof of a building for it's very first time, is.... yawnnnnnnnnnnn, no matter how cost effective, no matter the carbon saved, etc....
    There's nothing wrong with PR to get peoples attention - at which time you can direct them to what works.
    The client, who due to DER's huge costs, are only those who can truly afford it, don't need the savings to replenish their wallets, and just want to do it because it's a good thing, foots the bill for the PR.
    Win - Win.
    I wouldn't try to get rich doing DER's, but they have a place in one's portfolio of projects.

  15. GBA Editor
    Martin Holladay | | #15

    Response to Russell Higgins
    You wrote that "the clients [of deep energy retrofits] ... due to DER's huge costs, are only those who can truly afford it." That's true, and I mentioned such clients in my article. I wrote, "Of course, any homeowners who are committed to reducing their environmental impact are free to invest in a deep energy retrofit if they want, even if the payback period is 100 years or more."

    You and I agree that the type of jobs we are discussing -- jobs in the $100,000 to $200,000 range -- are only an option for very wealthy homeowners. We also agree that these clients "don't need the savings to replenish their wallets."

    Although these facts seem obvious to me, there is a group of designers who react negatively to this analysis, for emotional reasons. Those who question the logic behind deep energy retrofits are branded as traitors. For example, when this article was published yesterday, several designers reacted negatively on Twitter:

    "I'm not buying it."

    "Some incredibly naive assumptions about the future cost of fossil fuel energy plus climate costs in it."

    "Is this a prank?"

    "PVs, no matter how cheap, don't make cold, damp, leaky homes any more comfortable."

    "Seems to be a very narrow economic analysis not considering wider issues."

    "You're misrepresenting yourself & your blog. It should be called 'Musings of a Simple-Payback Nerd.'"

    "You imply that homeowners, energy consultants, etc. are stupid not to tailor projects to payback."

    "You might as well be writing PR for ANGA/fracking, as you assume rosy projections about NG price + availability."

    "That's the problem. It's not just about cost. What about health, comfort, climate change etc.?"

    "How about comfort? Durability?"

    So, why are all of these people reacting negatively to this article? Do they all really advocate energy retrofit jobs that cost over $100,000? If so, they are operating in a rarefied universe, and are providing services to a narrow elite.

    1. mattbrennan4 | | #100

      A lot of really great points here. To say all DER's are $100,000+ or close may be a bit of a jump as its definitely a sliding scale for each project. Maybe we should coin a term for opportunistic energy retrofit, that more likely reflects what I feel many may be doing when they improve the envelope as siding ages out or a basement reno is done.

      To the point of how solar is decreasing in cost, how much? What has been the effect on buybacks? Would have loved to see this in the article to make it not just thought provoking but useful in that part of the argument.

      1. GBA Editor
        Martin Holladay | | #101

        Q. "To the point of how solar is decreasing in cost, how much?"

        A. The attached graph is from NREL in 2018, showing an installed cost for residential PV systems of $2.70 per watt. Many homeowners pay more, but some pay less. Moreover, costs have dropped since 2018. The cost in 2010 was over $7 per watt.

      2. charlie_sullivan | | #102

        The term you are looking for was coined by the editors of Home Energy Magazine, who published a book called "No regrets remodeling" on exactly that topic.

        It's about "opportunities for improving their home's energy efficiency and comfort at one of the most critical junctures in home ownership. That moment comes when homeowners are faced with the decision to remodel a recently purchased or existing home, or due to a component failure, need to upgrade their home's HVAC, appliances, lighting, or other energy-related systems."

        There's a pdf of it at

  16. jinmtvt | | #16

    margin maybe ?
    You can't grab 10 000$ designing fees out of a 15 000$ project ..
    But on a 150 000$ invoice, 10 000$ might sound reasonnable ??

    Same reason why auto repair shots are all installing "new" parts in favor of recycled used auto parts...the margin profit being much larger .

  17. Expert Member
    MALCOLM TAYLOR | | #17

    On the list of complaints I'm surprised you didn't get "If you borrow the money it doesn't count as a cost". I've tried and tried but that piece of economics still puzzles me.

  18. Expert Member
    MALCOLM TAYLOR | | #18

    Reply to Russell
    "The client, who due to DER's huge costs, are only those who can truly afford it, don't need the savings to replenish their wallets, and just want to do it because it's a good thing, foots the bill for the PR.
    Win - Win."

    But what are you publicizing? That you can reduce energy costs without worrying about budget or any analysis of the embodied energy of the materials used? Of what use is the PR if it is promoting something unrealistic? Implicit in this approach is the belief that as you put it: it should be done "because it is a good thing". That belief need some fleshing out. Why is it a good thing?

  19. Paul Eldrenkamp | | #19

    general thoughts about "3 DERs, 3 Years Later"
    Every client for whom we've done a DER would do it again. They like comfortable, efficient, resilient, healthy, quiet, bug-free homes. We continue to do DERs for those reasons. We're about to start another one in May, in fact.

    DERs are undeniably niche projects, like $150K master suites or kitchens. You can make an argument that they're better investments than the master suite or kitchen because in 30 years a DER will still be performing as intended whereas in 30 years that master suite or kitchen will look dated and worn and like it needs to be re-done. But they're still niche projects, and because of their cost will never have a broad market base.

    Be careful of making conclusions about the cost-effectiveness of a DER based on cost data for one project. The first question to ask is, "Did anybody make any money on the project, at that cost?" If DERs are to be scalable, they need to be profitable. I learned after a few DER projects what I needed to charge for them to be able to make a modest net profit (4% to 5%), and that hard-earned knowledge made them increasingly difficult to sell.

    To respond to the Twitter poster who wrote "Seems to be a very narrow economic analysis not considering wider issues": With a clients’ help, we did an analysis of a project in 2011 that made the following assumptions: $1.72 per therm of gas; 3% annual energy inflation over general inflation; societal costs of $350 for each ton of carbon, plus 3 cents for each kWh of electricity and 1 cent for each therm of natural gas; a discount rate of 4.25%; 75 year service life for the insulation component of the work; and 30 year service life for mechanical and on-site renewable systems. With those assumptions, the net present value in 2010 of a $250K investment in a DER was about $100K. Meaning that, given those assumptions, it was a not a good investment if the primary goal is mitigating climate change.

    If you disagree with these assumptions, let me know what yours are and I’ll run the same analysis to see how much the net present value improves. Keep in mind that if I keep my other assumptions from that 2011 analysis unchanged but input our current local price of $1.40 per therm of gas, the net present value for the project drops from about $100K to less than $50K. In other words, the past three years have only made the investment look worse.

    In my experience, the only way to make DERs look compelling from a climate change-investment point of view is to make assumptions about the future so extreme that they would not be taken very seriously even by those experts who are profoundly worried about climate change.

    That being said, if you're finishing just the basement or attic, for instance, I think it makes sense to do those spaces to DER standards ( We aim for "no regrets remodeling" and doing basement and attic work to DER standards is one way to achieve that goal, in no small part because of the non-energy benefits. Just don’t pretend the projects make sense purely from a carbon reduction point of view.

    Finally, the energy required to implement a DER -- in particular one that uses a lot of foam insulation, as most of them do -- is not trivial, easily equaling 10 years or more of pre-project heating energy. This includes not only the embodied energy of the materials but also the transportation energy required to get the crew to the site every morning and back home at the end of the day. Carpentry crews often don't live in neighborhoods where people can afford to do DERs and so have to commute a distance. Very preliminary research we're doing indicates that the crew transportation energy required to do a DER can represent over 50% of the embodied energy of the DER. This is in part because these projects take months to do -- week after week of crews getting to the site in cars and trucks whose engines are 25% efficient (when moving).

    By contrast, a PV installation takes a few days to complete and so the embodied energy represented by crew transportation for a PV installation project is a minuscule fraction of that for a DER. This is rarely factored into the equation when comparing DERs with PV, but if acknowledged, makes PV look even better—like it or not.

  20. JonathanTE | | #20

    Re: comments 19 and 4
    I appreciate Paul Eldrenkamp's fleshing out of his DER experience on the numbers (comment 19). I think it adds further to the point Robert Swinburne had in comment 4, which may or may not have been intended with full seriousness. I think it should be taken with full seriousness. For those home owners who are considering a deep energy retrofit--with the deep equity resources to match--because they place an extremely high value on reducing carbon emissions, Swinburne's suggestion to do merely solid weatherization at home and take all the avoided expense of a DER and donate it to low-income weatherization is spot on. The carbon reduction per dollar will be vastly greater. If the world goes to climate change hell in a handbasket, no one will care that a few houses here and there were DER'ed. (Apologies to anyone who has done or plans to do a DER. I'm sounding more judgmental than I personally feel.)

    Paul, I noticed that your list of features the customers love is as much about hedonism as tree hugging. Do you have a sense of what features are the strongest motivations? If your DERs had resulted in low-carbon (emitting) homes, but they were as loud and bug-ridden as before, would your clients have proceeded? Would they have done it only for the quiet and the comfort? To what extent do you think self aggrandizement plays a part--people wanting to be "greener than thou"? (I realize you may not necessarily want to answer all of this in public, in case your answers aren't flattering toward your customers and they might happen to read this blog.)

  21. GBA Editor
    Martin Holladay | | #21

    Response to Paul Eldrenkamp
    Thanks very much for taking the time to share your hard-earned knowledge on this topic, and especially for sharing your careful calculations of the net-present value of these expensive retrofit jobs.
    I also appreciate your point about the energy required to deliver workers to and from a construction site.

    While advocates of deep energy retrofits imply that those who are skeptical of the value of such work (like me) are naive or haven't bothered to do the calculations, it turns out that the eager advocates of deep energy retrofits are the ones who haven't sharpened their pencils and spent time with a calculator.

  22. GBA Editor
    Martin Holladay | | #22

    Response to Jonathan Teller-Elsberg
    Thanks for your comments. I appreciate your observation: "I noticed that [Paul's] list of features the customers love is as much about hedonism as tree hugging."

    The same could be said about some of the comments posted on Twitter, at least three of which mentioned that one reason to perform a deep energy retrofit is comfort.

    Just when I think that our society must have finally come to an end of our decades-long journey to ever-higher levels of comfort -- as shown in our vehicles, which are like traveling living rooms, or in our obsession with temperature control in our homes -- I discover that the obsession still rages unabated in the American soul. In the last few years, marketers have tried to convince me that the thread count on my sheets is probably too low -- one more factor that must be undermining my comfort.

    And Dr. Wolfgang Feist has often explained that if there is any surface in my home that is more than a few degrees different from the air temperature, my body heat might radiate toward that cold surface, resulting in -- gasp -- a lowering of my comfort.

    So, it's true: a deep energy retrofit is one way for Americans to become more comfortable. But when will this obsession with comfort be satisfied?

  23. user-1072251 | | #23

    I agree with Martin's premise
    I agree with Martin's premise that DER's are too expensive, but let's look at the possibility that there is a less expensive way to get the job done. Dana recommends recycled foam; having used it I can vouch for the cost savings in one of the most expensive materials for the job, but it does nothing for the high cost of long screws or for the high cost of labor. And Paul talks about the high cost of labor and their transportation to the site.

    I think there is a potential in looking at the cost savings in giving up on foam with all it's issues, including installation labor and the inherent problem of installing an exterior vapor barrier (which in turn leads to requiring minimum amounts of the stuff). I've been considering the Larsen Truss model, but prebuilt exterior "brackets" including floor trusses and I joists are larger than what might be needed, and site built ones can require additional labor.

    Do we really need to add R26 to the walls? Would a vapor open R13 or R19 Roxul be sufficient when combined with a good air seal and a thermal break? What are the options for similar roof upgrades?

    There are lots of examples of a wide variety of methods for exterior upgrades, but the consensus settled on adding foam which has proved to be expensive to the point of being unaffordable to the majority of homeowners. Before we throw out the idea of DERs, lets take another look at alternative and simpler methods to upgrade our housing stock.

  24. dankolbert | | #24

    Labor transport
    On one of our big jobs, we recommended, jokingly (but perhaps should have pushed for it seriously!) that we add a line item for an electric car for my lead, who lived an hour from the job.

  25. GBA Editor
    Martin Holladay | | #25

    Response to Bob Irving
    You suggest, "Let's look at the possibility that there is a less expensive way to get the job done."

    By now, we have good data on deep energy retrofit costs; see my earlier article, The High Cost of Deep-Energy Retrofits, for more information on the topic.

    If you are suggesting a different approach -- what Dan Kolbert calls a shallow energy retrofit, or what most of us call weatherization -- then I agree with you. This approach requires the designer to use cost-effectiveness as a criterion for choosing which measures to implement.

  26. mrbreadpuddin | | #26

    Deep energy retrofit
    Another possible counter argument: houses with unattractive, failing, lead paint covered or asbestos exterior finishes might be candidates for a deep energy retrofit in conjunction with an exterior remodel.

  27. user-1072251 | | #27

    No, I'm suggesting a hybrid
    No, I'm suggesting a hybrid approach starting with weatherization, but including increased exterior insulation without the foam (which was used in the four Buffalo examples) if possible. Obviously this means that one would need to start with a home that needed new siding (and roofing if the roof is involved).

  28. user-1072251 | | #28

    In your example of

    In your example of the four Utica (not Buffalo; sorry) houses, it would be helpful, before dismissing them all as being too expensive, to have a breakdown of the costs involved. Some of the work, what you are calling "weatherization" would presumably have to be done anyway; stopping the drafts, upgrading the out-of-code issues, repairing damp basements. Other parts such as replacing failed siding would also need to be done. The cost of replacing windows could be broken down to compare the use of triple pane vinyl to the Serious windows used. Many DERs I've read about use cement board siding rather than either vinyl or local pine clapboards; absorbing the additional cost of the cement board installation into the whole DER. Of the total unit cost (you use $88k) the real question needs to be: what is the additional cost to add insulation to the envelope? What are the avoidable costs vs non avoidable costs? What areas could costs have been reduced by using materials whose costs align better with the project?
    Your article is a perhaps a good example of the DER projects we have seen to date, but have found to be impractical. Even with PV. we still need to upgrade our housing stock; to repair and replace things that are not working. We also still need to find a way to affordably add insulation to buildings that need it; a way that is repeatable, We haven't yet found that way, but it is not yet time to give up.

  29. GBA Editor
    Martin Holladay | | #29

    Response to Bob Irving (Comment #27)
    I would be delighted if builders attempt one of your suggested approaches and report their cost data back to GBA so we could see if your hunch is right.

    I'm guessing that your suggested approaches won't cost any less than jobs using exterior rigid foam. Builders have been performing wall retrofits with Larsen trusses for more than 30 years, so we have pretty good data on those jobs. (In most cases, they aren't any cheaper than rigid foam retrofits.)

    When it comes to mineral wool retrofits, time will tell. I don't think there is any evidence that such jobs save money compared to exterior foam.

    As a reminder of how long builders have been doing retrofit jobs with Larsen trusses, it's worth reviewing the Fine Homebuilding article from April/May 1984 titled "Retrofit Superinsulation." (For more information from this article, see All About Larsen Trusses.)

    For more information on a retrofit job using exterior mineral wool, see Wrapping an Older House with Rock Wool Insulation.

  30. GBA Editor
    Martin Holladay | | #30

    Response to Bob Irving (Comment #28)
    You wrote, "In your example of the four Utica ... houses, it would be helpful, before dismissing them all as being too expensive, to have a breakdown of the costs involved."

    See the table below. For more information, see the following pdf file of Greg Pedrick's presentation: Deep Energy Retrofits Pilot (DRP) for Cold Climates.


  31. dankolbert | | #31

    How to calculate costs?
    And yes, it's critical that we account for costs accurately. If a house needs re-siding, how much of the eventual cost is the re-siding and how much the exterior foam? Lumping them all together as a DER doesn't help us figure out the cost effectiveness.

    My point (and I believe that of Paul E.) is that tearing off good siding to add insulation is hard to justify. Whenever we have the opportunity, we try to upgrade a home's performance. But we're wary about "creating" opportunities.

  32. GBA Editor
    Martin Holladay | | #32

    Response to Dan Kolbert
    I agree with your statement: "My point (and I believe that of Paul E.) is that tearing off good siding to add insulation is hard to justify. Whenever we have the opportunity, we try to upgrade a home's performance."

    I wrote something similar in my 2009 article, "Roofing and Siding Jobs Are Energy-Retrofit Opportunities."

  33. dankolbert | | #33

    Ext foam vs. DPC
    We just did a quick and dirty calc for a renovation we're looking at; using TJI's as trusses and filling them with cellulose would cost at least twice as much as using new rigid and strapping. Your mileage may vary.

  34. nick57 | | #34

    Getting back to the PV side
    Getting back to the PV side of the discussion for a second in relation to reducing carbon emmissions. With respect to installing a grid tied PV system, I have never understood clearly whether there is a linear relationship between the amount of kw the PV system produces and the reduction in carbon emmissions that results. For instance, if my local power plant emits 100 units of carbon for each 10kw of energy produced, will a 10kw PV system eliminate the exact same amount (100 units) of emmissions? Another way of saying this is to ask whether a kw of energy produced by a PV unit saves the same amount of emmissions as a reduction in use of a kw of electricity ? Does this depend on many factors such as whether the electricity produced is on/off peak, the capacity of the grid, whether the plants are running on main fuels (e.g., coal), peak load fuels (e.g., gas turbines) etc?

  35. GBA Editor
    Martin Holladay | | #35

    Response to Nick DeFabrizio
    There are some inefficiencies in PV production (mostly due to the inverter, with some line losses) -- but 92% to 95% efficiency is reasonable for a grid-tied system. Whatever electricity is produced by the PV system is used.

    If your local utility has a single generating station, then the PV power displaces the power produced by the generating plant. If the local utility has multiple source of electricity, then time of day and other factors obviously matter.

  36. nick57 | | #36

    Thanks Martin. Since the
    Thanks Martin. Since the turbines need to run anyway, I always figured that the actual amount of emmissions reduction from a small amount of reduced power (whether from PV replacement or efficiency reduction) was small. But maybe not.

  37. Albany_Chris | | #37

    PV Panels will keep getting better...
    Martin commented that each time he does the analysis the argument in favor of PV keeps getting stronger. Prices for PV will only keep falling. For those of you on the fence, how do your beliefs hold up when PV prices fall another 25%? 50%? Despite the arguments of Dana (#12), battery technology is what will be holding us back now, and there is no big improvements seen there, only very slow incremental improvements, but even so energy will only get cheaper.
    I recently read a Book titled "Abundance: The Future is Better Than You Think" where the author Peter Diamandis postulates that energy will become nearly free over the next few decades. A very provocative idea and interesting reading. It certainly turns the long term payback period discussions on their head...

  38. Alex Wilson | | #38

    Missing is the benefit of passive survivability
    The other justification I often make for going beyond insulation levels that have reasonable rates of economic return in favor of PV is that the vast majority of PV systems are grid-connected (stand-alone PV systems with batteries cost far more), and when the grid goes down and you lose your heat it's important to maintain livable conditions passively. High insulation levels provide that passive survivability or resilience.

  39. GBA Editor
    Martin Holladay | | #39

    Response to Alex Wilson
    You're right. My guess, however, is that it's possible to make significant improvements in passive survivability without going all the way to the usual deep energy retrofit formula of 10-20-40-60.

    The most significant performance improvements, I'll wager, would come from air sealing efforts.

  40. Expert Member
    Dana Dorsett | | #40

    The carbon offsetting of PV...
    ... isn't exactly the annual average of the local grids carbon/kwh. PV output occurs primarily during demand hours, a time at which dispatchable fossil burners are ramped up. And PV output is still usuall pretty good during the air conditioning peak power loads (usually the absolute high peaks.) Most of that peak power on most regional grids is delivered by lower efficiency but highly responsive gas or oil burners, not baseload nukes or high efficiency combined-cycle gas.

    Since the time of day and even the time of year makes a difference, there is no simple answer. But in general, PV will be offsetting MORE carbon per kwh delivered than the annualized grid average, since it's offsetting during higher demand and peak demand periods when the carbon-intensity of the grid is higher than average.

  41. JonathanTE | | #41

    Re: Albany Landlord and "Abundance"
    Sorry, but you lost me at "energy will become nearly free." Deja vu all over again? Too good to be true usually is just that. I recommend trying your best to erase all memories of that book so you don't start making decisions based on snake oil wishful thinking.

  42. wjrobinson | | #42

    I agree with Albany landlord.
    I agree with Albany landlord. Get PV and get an ebike and Tesla or Leaf etc. Even better get off the land and onto a boat as I see no end to the rise in property taxes and all other taxes. Every government is broke and or bonded and borrowed to 10 times their costs. Future promised healthcare and pensions add up to quadrillions whatever that number is.

    Energy is never going to be a problem till the sun hiccups.

  43. JonathanTE | | #43

    Re: "Abundance"
    AJ (and Albany), the sun will keep shining, no doubt. Energy will continue to exist. That is quite a different statement than "energy will be nearly free," and I can't see how that has anything to do with property taxes. It's not that it is impossible in theory for energy to become amazingly cheap, it's just that that seems a really bone-headed assumption to make when making decisions that affect or depend upon energy consumption. If energy is going to become nearly free in the near future, does that mean that you are cheating your customers out of tens of thousands of dollars by building them efficient homes? After all, that efficiency isn't worth bupkiss if energy is going to be nearly free. All they need is a big tent and gargantuan heat pump.

  44. RZR | | #44

    I don't think you need a
    I don't think you need a bunch of fancy present and future cost analysis that may or not be accurate, probably about as accurate as looking in a crystal ball, or bogged down tech data some client won't understand or may understand better than you. Below is a good article on what clients want and how/where to sell it. A DER does no good if it can't be sold. Better watch the claims and FTC too :)

  45. Expert Member
    Dana Dorsett | | #45

    Reponse to Albany Landlord (#37)
    The panel costs are now a small fraction of a grid tied PV array, and in fact are less than the "customer acquisition" cost (the advertizing/bidding proposal/hand-holding costs.) In MA the unsubsidized cost for grid tied PV is running $3.50-$4.25/watt for turn-key sub-10kw grid-tied, but in streamlined & competitive markets like Germany and some parts of Texas it's now coming in under $2/watt. Most analyst estimate residential grid-tied will come under a buck-fifty a watt average in the US before 2020, and utility scale under a buck. Not exactly free, but at a lifecycle cost of energy lower than any other grid source. Clearly price will not be the limiting factor for the expansion of PV as a grid source.

    But like price, battery technology is also not the limiting factor for PV becoming an all-dominant player in the electricity markets: Real estate is. Recent NREL analysis came up with an estimate that only ~25% of the rooftop area in the lower 48 are suitable for photon-farming. But battery technology for grid storage is seeing more than incremental improvement, at least from a cost point of view. While progress in high power density technology (necessary for electrification of the transportation sector) such as lithium ion is incremental (but also poised for significant reductions in cost- Tesla is going after that in a HUGE way), there are now disruptive very low cost technologies for grid storage just now entering the market, and it's not just Ambri's liquid metal battery approach. Grid storage is a red-hot market being chased by venture capital right now, and the international market for grid storage is huge- currently far greater in Europe than the US, but starting with CA's recently passed mandate the growth here will exponential for at least another decade.

    But that's irrelevant if you don't have site access to the sun. The PV vs. DER dichotomy is a false one, cooked up at a time when PV was the paradigm (straw-man?) for "expensive energy". But it was as false then as it is now- it's just more obvious now.

    At any PV/other energy price you still need the infrastructure of sufficient energy to deliver that energy, and that infrastructure has both capital & maintenance costs. A more useful analysis than PV vs. DER lifecycle costs would be the lifecycle costs of the infrastructure + energy costs for supporting the higher loads vs. the lifecycle costs of lowering the load, and where the crossover points with different load reduction strategies. Clearly cellulose at 3 cents/ R-foot is going to have a different financial crossover point (at any presumed future energy cost) than closed cell polyurethane at 17 cents/R-foot, or virgin stock EPS/polyiso at 10 cents/R-foot.

    There is no way to hit Y2050 carbon reduction targets without dramatic improvements in both building efficiency and transportation sector efficiency- you're not going to get there by merely producing enough cheap PV output to cover for the higher loads of inefficient use of that energy. As an approach Deep Energy Retrofit isn't insane- in fact it's necessary. Something like 80% of the buildings that will be around in Y2050 have already been build. The "How deep is deep enough?" question is still valid, even if it isn't rightly couched in terms of it's comparative costs of PV-power (which will be very cheap very soon), or the ROI just the energy offset for that last R5 of insulation. Both timing and methods of the retrofits affect the financial analysis, but ignoring the energy use levels of a circa 1963 house (or a circa 1890 house) for the next 35 years, thinking you can just more cheaply buy enough PV (on site or elsewhere) to adequately cover the load isn't really a viable option without the necessary solar-real-estate or grid infrastructure.

  46. user-757117 | | #46

    Response to Dana
    You wrote:

    There is no way to hit Y2050 carbon reduction targets without dramatic improvements in both building efficiency and transportation sector efficiency- you're not going to get there by merely producing enough cheap PV output to cover for the higher loads of inefficient use of that energy.

    Not sure which targets you're referring to, but in any case I would add that there is no way to hit those targets without taking some steps to mitigate against further growth of energy demand period.

    The problem isn't likely to be a shortage of renewable energy so much as a "longage" of expectations.

  47. adamsten | | #47

    Great Article - PV is the key to real carbon savings.
    I've run a few scenarios for Colorado homes looking at energy retrofits, PV and electric vehicles (EV). The typical annual carbon savings from a $5,000 to $10,000 retrofit comes in at around 4 metric tons. If you were to drive an EV instead of a 25 MPG car and power it with the dirty Colorado grid, you'll save around 2 metric tons compared to gas, but if you power the whole house's electric demands and the EV with PV, you'll save a total of 14 metric tons for all three improvements. There's no doubt that making the house less leaky and better insulated will make for a more comfortable home, but do we need to go all the way with a deep energy retrofit? Let's hit the low hanging fruit of energy efficiency, then concentrate our efforts on PV and EV.

  48. Expert Member
    Dana Dorsett | | #48

    80% below 1990 levels...
    ... is a commonly bandied carbon-reduction target for the already-developed world in order to limit the Y2100 temperature rise to merely "broil". Some countries (eg: the UK ) have written "80% below 1990 emissions by 2050" into binding legislation, other countries have set themselves binding shorter term goals, but on the same end goal. That's also the stated target in various pieces of proposed climate legislation in the US.

    Greening up the grid only gets you part way there. Cutting space heating/cooling loads and moving off of fossil-fuel heating into heat pump technology would be another huge step, as would electrification of most of the private automotive fleet. But you can't get buildings AND cars off of the fossil-carbon habit just by covering the entire states of Arizona, or Texas with cheap PV and boxes o' batteries, with long jumper cables to the rest of the US. The notion that it's affordable or desirable o power the east coast from midwestern wind resources (a popular idea in some quarters just a few years ago) has be pretty soundly debunked.

    Reducing building loads to where site-sourced energy (or nearby-site sourced energy) can carry a large piece of it is still going to be a large and mostly affordable slice o' the low-carb pie, but it's going to take more than just the lowest possible hanging fruit. While retrofitting every home to where it's total energy use is 80% below 1990 levels isn't financially viable, there are many cases it clearly is, especially when handled at a lowest cost basis, and staged at opportunity moments such as re-siding or re-roofing, etc that only come along every 20-50 years.

    On the up-side, electricity demand in the US has been flat or falling for nearly a decade now, mostly the product of efficiency efforts, despite the protestations of the "you can have my incandscent light bulbs when you take it out of my dead scorched hands!" types. But the efficiency well (both electrical and heating/cooling load) well is still pretty deep & cheap compared to new generation of any type. If the US got serious about targeting efficiency over & above energy production you wouldn't need to build new power generation for decades (if ever). While a quarter million 'merican shekels per house like the 61 Oakwood Avenue straw-man won't make sense, half that might, compared to the capital cost of the PV & grid infrastucture required to support the original energy load for the next century. But it doesn't have to be that deep (and certainly not that expensive) to end up with something that meets or exceeds the "80% below 1990 levels by 2050 " carbon goals.

  49. user-729621 | | #49

    The Treehugger post that I didn't publish
    I spent a lot of time last weekend thinking about this issue and drafted a long post for TreeHugger, where I am managing editor, but decided that we shouldn't have one green blog criticizing another green blog, so I have edited it and put it here for discussion.

    Over at Green Building Advisor, Martin Holladay writes a provocative post with the title Deep Energy Retrofits Are Often Misguided. My first reaction on reading it was to tweet:

    "OK this contradicts everything I write or teach."

    Now that I have had time to think about it, I realize that Martin is at least half right, and that we have been saying much the same thing about where people should put their money. Martin starts with a bit of history and writes about the the first people to do what became known as deep energy retrofits, (defined as " whole-building analysis and construction process that uses "integrative design" to achieve much larger energy savings than conventional energy retrofits")

    "These pioneers understood what was wrong with American houses: They leaked air; they were inadequately insulated; they had bad windows; and their duct systems were a disaster. Occasionally, these energy nerds would scoff at millionaire clients who were more interested in “green bling” — a phrase that usually described photovoltaic panels — than they were in reducing air leaks in their home’s thermal envelope."

    Martin then describes what he calls a "tribe belief: that improving a home’s thermal envelope is preferable to installing renewable energy equipment." However he questions whether that belief is still justifiable.

    "Several factors have changed since these beliefs were first formulated. For one thing, fossil fuel prices have stayed low; for another, photovoltaic equipment has gotten dirt cheap."

    The latter may be true but as for the former, my natural gas just jumped 40% thanks to the cold winter. The province of Ontario has switched from coal to a lot more natural gas, and what will happen to electrical prices is unknown and will probably be pushed to after the next election. He's just wrong on that point. Putting solar on my roof won't reduce my carbon footprint either; I pay extra for Bullfrog green power that comes from water and wind.

    The fact is, deep energy retrofits have never made economic sense in terms of payback and are questionable building practice for a lot of older homes. Put too much insulation inside a brick wall and you kill the heat movement that drives out moisture. Change the windows and you ruin the character of the house and switch windows that have stood for a hundred years with replacements that will lose their argon fill in a decade and rot from the sun in twenty years, and barely perform better than the ones that were removed. Seal the house up too tight without proper ventilation and you create a sick building.

    But "reducing air leaks in their home’s thermal envelope" certainly does make sense. There is a ton of low hanging fruit that people can do, from caulking to attic insulation to duct sealing to lighting to appliance changes that pay off fast. Martin doesn't say this. He says "Assuming the house has an unshaded south-facing roof, it’s probable that the best energy-saving measure will prove to be the installation of some solar bling."

    Just say no. First of all, It is ridiculous to say that people should put solar panels on their roof why they continue to live in cold draughty houses. Comfort matters, and a solar panel doesn't change that.

    Secondly, such a theory only works for Americans who live in nice suburban houses with big roofs facing south. We have a lot of homes to retrofit in North America, and that is just a small proportion of them.

    Thirdly, as Alex Wilson has pointed out in comments and on his website, insulation gives you resilience. He writes:

    The other justification I often make for going beyond insulation levels that have reasonable rates of economic return in favor of PV is that the vast majority of PV systems are grid-connected (stand-alone PV systems with batteries cost far more), and when the grid goes down and you lose your heat it's important to maintain livable conditions passively.

    Finally, Martin's fondness for solar bling would make it impossible for the other things we have to make happen: higher density (less roof area per person), more trees (shading battles). We simply can't afford the kind of land use that lends itself to useful rooftop solar.

    A solar panel is not an alternative to having a properly sealed, insulated and weatherized house.

  50. user-1006269 | | #50

    Not die in the cold
    A DER or super insulated new home offers great comfort--mentally and physically in northern climates: If (and when) the power goes out, the house and its occupants can survive. Having lived through the Ice Storm of 1998 in Maine, we had built a super insulated home for a friend a year or two before. It was an R-40 shell on an insulated radiant slab that was heated with propane. The windows were low-E argon double glazed. Nothing real exotic like a Passiv Haus. It was built for a single older woman. She had her family come stay with her. She had no power for 7 days. No solar gain since she was in the woods.
    She did have a gas cookstove. I spoke with her 6 months after the fact. My first question was what was the temperature after 7 days of no power, not much solar gain in a typical January in Maine.
    She told me it was 60F teetering on going to 59F.
    I said, "Well, you used the cookstove oven to keep warm, as many folks did." She said they did not, only using the stove for cooking. Granted there were 6 people in the house, but the tight, insulated shell got her through.
    Until we have a stand alone PV system that will do everything we want it to do, I suspect anyone in (at least) the northern tier of states can make a good case for highly insulated structures.

    [Editor's note: To continue reading comments, advance to page 2 by clicking the box with the 2, below.]

  51. user-757117 | | #51

    Response to Dana
    Thanks for clarifying which target you were referring to.
    I can agree with many of the points you're making.
    But I am skeptical that fairly recent reduction of electrical demand is largely due to efficiency measures and not due to more complex dynamics.
    And I remain skeptical that a (ever more concerted) combined build-out of renewables combined with efficiency measures will achieve even the target you described.
    Recent global data still indicates that despite [amazing in some cases] growth of renewable sources of energy, growth in fossil fuel production has also grown to the extent that renewables still only make up roughly the same proportion of the global energy mix as they did 20 years ago.
    Speaking of "broil":

    Growth in renewables, globally, have not displaced fossil carbon but have simply served to increase the size of the "hive" so to speak (what else should we expect from economic system obsessed with growth-at-any-cost?).
    Clearly it is possible to observe differences in data at a national level, but in today's globalized economy it has become difficult to say with any credibility (some exceptions) that the people of other nations with a "dirtier" energy mix are solely responsible for those emissions (ie, when our own nations export to them the coal that they burn, or when we buy the stuff that they manufacture to meet our consumptive demands, or when we set an example of "first world" expectations from life that they desire for themselves).

    So it becomes hard to see how we will ever make any serious effort to mitigate against worst case climate risks without overhauling not just our energy systems but our economic systems and cultural belief systems as well.
    That "longage of expectations" is the banana in the monkey trap that we have to figure out how to let go of fast - the hunter is on its way.

  52. user-974421 | | #52

    Sure about NG staying cheap?
    Weekly Natural Gas Storage Report

    for week ending March 21, 2014 | Released: March 27, 2014 at 10:30 a.m.

  53. user-974421 | | #53

    Shale Gas economics should be questioned
    From three and a half years ago...

    Shale Gas—Abundance or Mirage? Why The Marcellus Shale Will Disappoint Expectations

    Posted by Art Berman on October 28, 2010

    From last month...

    US shale gas and tight oil industry performance : challenges and opportunities

    Ivan Sandrea, OIES Research Associate, March 2014, Oxford energy

  54. user-974421 | | #54

    How then will these homes be heated?
    Solar isn't going to heat all those leaky, poorly insulated homes. The sun doesn't shine much in winter and it definitely doesn't at night. The days are short and cold, and the night is dark and colder, and the interior/exterior temperature gradient that much greater.

    I've attached the supply/demand graph from EIA's Natural Gas Weekly. I don't think it's fully recognized how much energy is used to heat our homes!

    And we definitely don't recognize how much we need to reduce our use of fossil fuels to meet our CO2e emission reduction obligations.

    From Kevin Anderson's Open Letter to the EU Commission president about the unscientific framing of its 2030 decarbonisation target"

    As the letter makes clear, for the EU to honour this commitment the Commission must find the courage to pursue an equitable and science-based 2030 decarbonisation target of around 80%. Anything less and the EU will renege on its 2°C commitments and, as the Commission rightly notes, bequeath to future generations a legacy of “devastating impacts”.

    It's quite questionable that there will be enough gas to affordably heat the huge stock of inefficient homes. And as an alternative I can't see how putting PV on the roof of these homes will do it, I'd be happy to be shown how.

    But if we're honestly going to address our obligation to subsequent generations then profoundly reducing the heating demand of the housing stock seems like the only option

    Of course, some may not be concerned about kids' futures, but the present generation may not come off to well... a search on "agriculture and drought" on Bloomberg points out that our food system is already under some stress.

    So at what cost does the payback of a Deep Energy Retrofit make sense? If we continue to externalize many real costs of our inefficient housing stock then of course a DER won't add up, but that means we are still not being honest about the real payback of a DER.

    Look at it this way, it's a lot more likely that something like another Hurricane Sandy comes along and knocks down a neighbourhood of houses because we didn't make the effort to profoundly reduce their energy demand.

    And when the likely storm caused blackout comes along, the retrofitted home is going to offer a lot more resilience and value to it's home-owner, and the community/municipality it is built in.

    Finally, we're going to need to put PV on every south facing roof available, to meet our (greatly reduced) energy demand, but it will only be of use to heat our homes if our homes need very little heating.

  55. GBA Editor
    Martin Holladay | | #55

    Response to Lloyd Alter (Comment #49)
    I think that we agree more than we disagree. Your apparent disagreements are based on misreadings of what I wrote and on straw men that you have set up in order to facilitate your opposition to my writings.

    I wrote that natural gas has gotten cheaper; you counter with the observation that the retail price for natural gas at your home hasn't dropped. Clearly, my generalization was not intended to cover every gas utility in North America. I am happy to stipulate that natural gas prices haven't dropped for every retail customer in every time frame one cares to look at. But if you want to look at natural gas price trends over the last 6 or 8 years, I think that there is a fair basis for my statement. (See the two graphs reproduced below.)

    But clearly, either of us can provide evidence for rising or falling energy prices using the same data -- all we have to do is adjust the time frame of our analysis to create the data set that proves any point we care to make.

    You wrote, "What will happen to electrical prices is unknown and will probably be pushed to after the next election. [Martin is] just wrong on that point." I've given up on predicting future energy prices, but evidently you haven't. Good luck with your predictions; you may be right, but predictions aren't data.

    You wrote, "The fact is, deep energy retrofits have never made economic sense in terms of payback and are questionable building practice for a lot of older homes." I'm glad we agree on that point.

    You wrote, "But reducing air leaks in their home’s thermal envelope certainly does make sense. There is a ton of low hanging fruit that people can do, from caulking to attic insulation to duct sealing to lighting to appliance changes that pay off fast. Martin doesn't say this." Heavens, Lloyd -- I've been saying almost nothing else for the last 15 years. This is a deliberate misrepresentation of what I have been advocating in my writings. Even in the article we're discussing, I wrote, "There are countless examples of low-hanging fruit that could be picked if we wanted to develop better incentive programs to achieve carbon reductions: we could increase our investments in low-income weatherization programs, for example..." Low-income weatherization consists of cost-effective energy-efficiency measures like the measures that you claim I'm ignoring.

    You wrote, "[Martin] says, 'Assuming the house has an unshaded south-facing roof, it’s probable that the best energy-saving measure will prove to be the installation of some solar bling.' Just say no. First of all, It is ridiculous to say that people should put solar panels on their roof when they continue to live in cold draughty houses."

    I never said that weatherization shouldn't be performed; in fact I explicitly endorsed weatherization. Your specter of a "cold drafty house" is a blatant straw man. Moreover, why shouldn't middle-class homeowners with an unshaded south-facing roof install a PV array? My brother just did. He lives in Massachusetts, and he is leasing the system for zero dollars down. He has been guaranteed electric bills that will be set at 80% or 90% of his current kWh rate, and at the end of the 15-year or 20-year contract (I forget which) he can either purchase the array at a steeply discounted price or allow the company that owns the panels to take them away. What's not to like? Zero dollars down, and cash flow savings from Day One. Of course homeowners want this deal. Homeowners instantly understand the advantages of this deal, and it's a mystery to me why green building advocates like you would write that installing such a PV array is "ridiculous." Why wouldn't a homeowner want a lower electric bill?

    You wrote, "Such a theory only works for Americans who live in nice suburban houses with big roofs facing south." That's more or less what I wrote, Lloyd -- although the homes don't have to be nice; they can be crummy. And they can be suburban, rural, or even (in some cases) urban. All you need is an unshaded south-facing roof, and a contract for PV installation that makes economic sense.

    I agree that added insulation makes a house more resilient, as you and Alex Wilson have pointed out. However, that fact doesn't undermine my arguments against $100,000 deep energy retrofits.

    You wrote, "We simply can't afford the kind of land use that lends itself to useful rooftop solar." So what are you going to do, Lloyd -- make it illegal for people living in houses with unshaded south-facing roofs to install PV? Your point is irrelevant to my article. Of course people are only going to install PV in locations where these systems work.

    You wrote, "A solar panel is not an alternative to having a properly sealed, insulated and weatherized house." Of course it isn't, Lloyd. I agree with you on that. And I never wrote anything to suggest that I didn't agree.


  56. ecdunn | | #56

    I have mostly finished my energy retrofit on my 1154 square foot 1977 ranch style house in Flagstaff AZ (USDA 5). Being a designer/builder of sustainable homes, I did most of the work myself. I added 2" of foam to walls and stem down 2', along with 6" of foam to roof sheathing. I have dropped by NG costs 50% over ten years. This January, the bill was for 55 therms of NG for a home that is heated by a single freestanding gas space heater.
    Still a little work to do on the wall between the garage and living room. I would estimate costs for the energy retrofit, including new Pella 3 panes (we chose these not just for energy efficiency but for great aesthetics, including the concealed blinds) would be about $11k. The rest of the costs would be attributed to the aesthetic changes. We now live in a very beautiful home.
    Another important side benefit is the fact that we gained usable space and we are actually comfortable in our home. Two north bedrooms can be used year round in a place that has 6 months plus of winter weather. My wife used to dominate the dining room, next to the gas space heater, to use as her water color studio. She now has it confined to the coldest north west bedroom. My office, in the other room, where I would sometimes shiver from the cold while I did office and design work is now, also, usable year round.
    This is an aesthetic quality issue and makes a home much more valuable, well worth it, to me and my wife. We basically have a new home for much less than building a new one. Comfort is often not mentioned as a reason to make a house tighter and better insulated. Surveys of what home owners want include granite counters and energy efficiency but you hardly ever see comfort listed (much less the idea of having usable space).

  57. user-757117 | | #57

    Response to Andrew Henry

    How then will these homes be heated?

    Maybe in part by having more people occupy the better enclosures that are available.

    I'm guessing that eventually circumstances will require us to rediscover the benefits of "huddling together" for warmth.

  58. rclepage | | #58

    retrofits don't have to cost $1/4 million
    You will be happy to know that Rob Dumont is alive and well and still helping make Saskatchewan a better place. We all understand that the most difficult challenge in a home retrofit is the building envelope. Vereco Homes is working with Rob to develop an exterior wall retrofit application(sWRAP) that significantly reduces the cost. We recently added ~R30 of insulation to the walls of a home in Saskatoon for under $15,000 (see

  59. GBA Editor
    Martin Holladay | | #59

    Response to Tom Gocze (Comment #50)
    You describe a new home that included R-40 walls and an R-40 roof or ceiling. These levels of insulation make perfect sense in a new home, especially in a northern climate like the one in Maine.

    You also wrote, "The northern tier of states can make a good case for highly insulated structures." I agree completely, especially for new construction (like the house you described).

    However, it's still hard to justify a $100,000 deep energy retrofit.

  60. GBA Editor
    Martin Holladay | | #60

    Response to Andrew Henry (Comment #54)
    Q. "How then will these homes be heated? Solar isn't going to heat all those leaky, poorly insulated homes. The sun doesn't shine much in winter and it definitely doesn't at night."

    A. GBA has lots of articles on space heating options. Clearly, PV power won't heat most homes. Options includes wood heat and natural gas; it's also possible to imagine a future in which wind-generated electricity provides much of the power for space heating needs using air-source heat pumps.

    Your point that PV power won't heat homes in December and January is frankly irrelevant to the point I'm making: that an investment in a deep energy retrofit doesn't reduce energy bills as much per dollar invested as an investment in a PV array.

    Finally, GBA has never said that homeowners who live in leaky, poorly insulated homes shouldn't fix them. Clearly, weatherization makes sense. Most weatherization work begins with blower-door-directed air sealing -- something that GBA has always advocated -- and also includes insulation improvements that are cost-effective.

  61. GBA Editor
    Martin Holladay | | #61

    Response to Ed Dunn
    Congratulations on completing energy retrofit work at your own home at a cost of $11,000. It sounds like this investment was a good use of your money and time. Energy retrofit work of the type you describe makes a lot more sense than a $100,000 deep energy retrofit.

  62. GBA Editor
    Martin Holladay | | #62

    Response to Ronn Lepage (Comment #58)
    This looks like a perfect candidate for new exterior wall insulation: a simple, one-story ranch without much decorative trim, and (apparently) adequate roof overhangs. If every house we were invited to work on looked like this, our work would be much simpler. Anyway, nice job -- at a very reasonable price.


  63. Expert Member
    Dana Dorsett | | #63

    Repsonse to Lucas (#51)
    While it's true that "the rise of the rest" has increased fossil fuel use worldwide more quickly than the developed world has been able to dial back, the aggressive policy implementation of renewabales in some quarters has renedered even some recently built fossil-burners uneconomic:

    You are correct the factors behind faltering electricity demand are complex, but they are not a total enigma. While many or most people have presumed that the flat/falling demand curve has been just an artifact of the recession and warmer than average winters, more careful analysis shows that efficiency has been a primary underlying driver, at least in the residential & commercial sectors. It's part of a long term trend toward efficiency, but a trend that has been recently accelerating faster than the increase in end-use function:

    This acceleration in the efficiency end seems to have legs, which is of significant concern to utilities and independent operators with generation assets that need to operate above a minimum capacity-factor to keep their business model healthy. (Georgia Power's foray into new nukes may prove to be a giantic albatross going forward.)

    The arguments against distributed renewables that may have had a rationale 30 years ago are quickly evaporating. Just this week in not-so-sunny Minnesota, a utility-scale PV operator's project that was bidding against combined-cycle gas won and was approved simply on the economics. Similar thing have been happening with wind power as well. Year on year reductions in cost, and increases in turbine efficiency have made wind competitive with $5/MMBU combined-cycle gas, and will likely beat $4/MMBTU gas very shortly. Even in an increasing demand environment (which will eventually happen), meeting the demand with more fossil burners isn't anything like a clear winner anymore- we are in the midst of a massive disruption of the industry. Despite a large legacy base of fossil burners, there they are becoming less and less competitive going forward.

    Yes, massive Chinese & Indian economic growth have driven fossil burning to greater heights, but even the growth won't go unfettered, and distributed renewables are as cheap and sensical there as in the already-developed world, and being installed and an accelerating pace now that the financial tipping point has been reached. The next 25 years won't look anything like the last 25 in terms of the renewable/fossil use ratio, whether policy makers steer the incentives toward renewables or not. But just how fast it happens will be influenced by policy makers, to be sure.

  64. user-757117 | | #64

    Response to Dana.
    Thanks for the link.
    I remain skeptical on that topic pending further investigation - I have read several other papers who's analysis incorporates some other factors and reaches different conclusions.
    You won't ever hear me poo-poo distributed renewable generation, I've always suspected its time would come.
    And while disruption within energy markets has certainly provided some interesting reading, so has the political backlash.

    Though things are always changing, the fundamentals that drive what we could call aggregate global societal behaviour aren't really changing all that much, that quickly.
    We humans are still as bold, exploitive and clueless about where we're actually headed as we've ever been, but I think there is always the temptation to think otherwise - despite the fact that this world we've made has become far more complex (and therefore far more unpredictable) than it has ever been in human history.

    It suffices to say that the stakes are about as high as they can be and I'll take it easy and "have some faith in the system" when some of these discomforting robust long-term global trends have actually turned around (verifiably, in the rear-view mirror) - in particular this one:
    You see, I am a product of my own training - in the air traffic control game, you don't usually get to play for very long by taking too much on faith.

  65. user-974421 | | #65

    The Big Picture

    Your point that PV power won't heat homes in December and January is frankly irrelevant to the point I'm making: that an investment in a deep energy retrofit doesn't reduce energy bills as much per dollar invested as an investment in a PV array.

    I'm worried that you are forsaking the big picture for a narrow point.

    All the PV on the roofs of all those conventionally built homes (not even talking about the leaky ones) will do is displace grid demand outside of winter. That's great but that does nothing to solve where the energy is going to come from to heat those homes in winter, by far the largest demand for energy of those homes.

    Are we truly going to do nothing about addressing our CO2 emission reduction obligations? Perhaps for a while longer, but human nature being what it is we will finally act once crisis is apparent.

    And having gone through most of the conventional pools of natural gas on this continent were now going after the source rock, by fracking shale. Were scraping the barrel and it costs a lot more money to scrape the barrel (as one of my links above points out). What are we going to do once we've run out of sweets spots in the shale plays?

    If there is perhaps one thing I learned from you over the years, and from the people you have written about it is to think of the house as a complete system. Yet it seems that having had that epiphany, few stopped to extend that thought and recognize that the house is just a node in a bigger system, the gas and electrical grids amongst others.

    A simple payback calculation on PV versus DER doesn't address the bigger issues. It's an apple and oranges comparison that doesn't address winter time energy demand. Sure the simple payback in the short term might be monetarily beneficial to homeowners, but in the medium term I suspect that we all will wish we'd been a good deal more ambitious.

    Simple payback analysis decision-making got us into the corner were in now... it's surely not going to get us out of it is it?

    We have some huge challenges ahead of us and you have the influence to help steer things in the right direction. Please don't take that responsibility lightly!

  66. user-974421 | | #66

    Huddled Masses

    I'm guessing that eventually circumstances will require us to rediscover the benefits of "huddling together" for warmth.

    Yup, it's looking that way.

    I know too many folks who should know better but are surprisingly oblivious or unwilling to examine energy related issues. And I've come to realize that it means we'll end up remarkably unprepared.

    P.S. I think I stumbled on your blog via Neven's ASI blog/forum? If it was your blog, I enjoyed reading about your place.

  67. GBA Editor
    Martin Holladay | | #67

    Response to Andrew Henry (Comment #65)
    You wrote, "All the PV on the roofs of all those conventionally built homes (not even talking about the leaky ones) will do is displace grid demand outside of winter. That's great but that does nothing to solve where the energy is going to come from to heat those homes in winter, by far the largest demand for energy of those homes."

    True enough. These PV arrays won't mow your lawn or shovel snow from your driveway, either. It's easy to make a long list of what the PV arrays won't do. I never claimed that these PV arrays would solve our winter space heating problems. If you want to discuss the best way to generate electricity during the dark months of winter, or the best fuels to use for space heating, we can. It's an interesting topic, and I already addressed it (briefly) in my last answer to your comments. But it's not the topic of this blog.

    You asked, "Are we truly going to do nothing about addressing our CO2 emission reduction obligations?" I hope not. As a political realist, however, I would have to admit that it sure looks like the U.S. government has chosen, as you put it, to "do nothing."

    I gave a two-hour presentation on this issue at the Southface conference in Atlanta, Georgia, in March 2013, so it's a topic I'm interested in, and one I've thought a lot about. Like many other analysts, I have concluded that the most effective policy step that the government could take to reduce carbon emissions is to enact significant carbon taxes. So far, our government hasn't done this.

    The tax revenue generated by carbon taxes could be used for two purposes: (a) to provide a rebate to low-income citizens, softening the blow of the increased cost of energy, and (b) to subsidize carbon-neutral energy generation or measures that reduce energy consumption.

    Clearly, I'm all in favor of measures designed to reduce residential energy consumption. I've been providing advice to homeowners and builders on these topics for years. That doesn't mean, however, that it's sensible to push deep energy retrofits (at $100,000 a pop) as a solution to our carbon crisis.

  68. user-757117 | | #68

    Reply to Andrew.
    That sounds like my blog alright and I'm glad you enjoyed reading it.
    I visit Neven's blog and forum as my main stop for things related to ASI.
    The contributions he gets really make that blog a unique and valuable resource - and he seems like a nice guy to boot.

    I thought this was well said:

    If there is perhaps one thing I learned from you over the years, and from the people you have written about it is to think of the house as a complete system. Yet it seems that having had that epiphany, few stopped to extend that thought and recognize that the house is just a node in a bigger system, the gas and electrical grids amongst others.

    In some ways it seems like more people are catching up, but not fast enough.

  69. wjrobinson | | #69

    Help me with the percentage
    Help me with the percentage change of CO2 makeup of the atmosphere.

    .038% CO2 now

    before the last two centuries

    .0379% being that 100/1,000,000 is .0001%

    yes no?

    The percentage of the atmosphere is so tiny that any effect is hard to comprehend just knowing the percentage.

    Much different is the percentage of change of CO2 compared to itself.

    300 going to 400 PPM is a 133% increase. That is a number that is alarming on it's face.

    The numbers will never sell to all people. Weather, crop failures... that gets one's attention.


  70. Expert Member
    Dana Dorsett | | #70

    Evidence of efficiency driving electricity growth into the dirt
    It's no just me an a few green-dreamers who think efficiency programs are a primary driver behind flat to negative demand for grid power, disrupting their business model. The utilities themselves are PAINFULLY aware of it, and taking some desperate measures:

    This is the same sort of self-preservation tactic utilities are taking against net metering of PV. But it's a tactic that won't have legs in the long term, even if it puts off shareholder pain for the time being. The economic winds are blowing against them, even if they can still garner support from the political & legislative bodies in some locations for now.

    Utilities that can adjust their business models sufficiently to get behind demand response, efficiency, and distributed generation NOW will be the ones with the reliable and affordable power in 20 years.

    The 3 cents/kwh quoted number for efficiency is oft bandied about and though true today, won't always be. But in states such as MA where utility profits have been decoupled from margin on kwh sale, where new generation is expressly disallowed unless it can be demonstrably cheaper than gaining that capacity with efficiency unless it's a renewable source, it's pretty tough to get permits to build ANY new fossil fired generation. The per-kwh lifecycle cost of efficiency is still cheaper than any new power source, and if rigorously mandated at the federal & state level it would do-in the renewables industry as well as the fossil burns & nukes (which is precisely why it won't happen.)

    Even the comparatively modest efforts in Indiana were proving too onerous to the utility stakeholders, despite the demonstrable benefit to the rate payers, a benefit so clear that the governor wouldn't sign the repeal, though allowing it to take effect, and is promising to introduce an alternative by 2015:

    In another 10 years that sort of balk by the utilities could lead to grid-defections by those with the means to buy an acre of rooftop PV and enough battery & cogenerator to back it all up, inviting the "utility death spiral" as more and more of the grid maintenance costs fall on a dwindling pool of ratepayers.

  71. RZR | | #71

    Man that's alot of comments,
    Man that's alot of comments, can someone please sum it all up into a few paragraphs and tell me bottom line how to make some money at it and get my clients to agree? That be helpful! :)

  72. Expert Member
    MALCOLM TAYLOR | | #72

    "tell me bottom line how to make some money at it and get my clients to agree?"

    Do you look menacing? If so just threaten them.

  73. wjrobinson | | #73

    I find the power of CO2 to
    I find the power of CO2 to effect life at such a low percentage of the air amazing.

    00.038% is CO2
    99.962% is not CO2

    And the debate is about 100 part per million increase. If that amount of change was compared to an increase or decrease of the amount type typed or not typed at this blog, it would be like just one of us deciding to add a period or not to one of the hundreds of sentences of this blog.

    That is to me at least mind boggling... blogging. + or - a


    just a


  74. lutro | | #74

    Passive survivability PV inverters
    Alex Wilson, and a few others, have mentioned that grid-tied solar means no power when the grid is down, hence diminished passive survivability. When we installed our grid-tied solar one year ago, our installer said if we really wanted it, we could get an inverter that would provide one 120VAC duplex outlet (15A?) that would remain functional when the grid was down. But they didn't recommend that inverter, for other reasons.

    What is standing in the way of being able to use all or most of a grid-tied PV system's output in a residence, when the grid is down? Is the cost of that kind of inverter excessively high, are we missing some essential piece of the technology, or has the market just decided not to provide the product, up to now?

    If a home could use two or more kilowatts of its own PV during part or most of the day, while the grid was down, that would add a significant input to the passive survivability equation.

  75. GBA Editor
    Martin Holladay | | #75

    Response to Derek Roff
    The short answer is that it is significantly more expensive to install a PV system that provides electricity when the grid is down than to install a system that doesn't.

    The easiest way to do what you want is to install a large battery that costs between $5,000 and $10,000. The cells of this battery have to be regularly checked, because their fluid level drops and the cells have to be watered with distilled water occasionally. Homeowners don't like the chore. Batteries with dry cells have a very short life span.

    The kind of inverter that you are describing performs a kind of magic -- it produces a limited amount of AC power without the stabilizing contribution of a battery system. The reason that the output of this kind of inverter is always a small fraction of the DC output of the PV array is that there is no predicting when a cloud will cover the sun. If you have a 2-kW PV system, and you were trying to run your 1,500-watt air conditioner on a sunny afternoon with no battery and no grid, what would happen when a cloud moved in? I guess there could be some kind of sensor that quickly shut everything down, like a circuit breaker. But the fact is, the DC output of a PV array is always fluctuating because of clouds. It's hard to use the power without the stability of a battery, which acts like a flywheel.

  76. user-1102578 | | #76

    DER vs solar is a wash
    This is an excellent debate and I thank Martin for bringing it up. It motivated me to re-crunch the numbers.

    Our DER increased the thermal envelope by 87% (addition,basement,attic) while reducing our utilities by 54%. It roughly saves as much energy as a 7kw solar array produces in New England:

    With that, without utility subsidy and assuming stable energy rates into the future neither our DER nor a 7kw solar array would be economically viable.

    Solar is viable with net metering but net metering is subsidy -- it is a free rental of a 100% efficient infinite battery. It costs the utility more then wholesale power. If one removes the subsidy, there is no solar configuration I could find on the market that could produce and store power off-the-grid for cheaper then our utility. In other words unsubsidized it would never pay for itself.

    Even though our rockwool+Tyvek DER method was considerably cheaper then the polyiso method, without our utility's subsidy our DER would take 50 years to pay itself back -- better then other DERs but still longer then its likely service-life. In other words like unsubsidized solar, if our DER were unsubsidized it would never pay for itself.

    But accounting for our utility's DER subsidy, the marginal cost of going from building code to DER (we needed a new roof, new siding, basement work, and an addition either way) will pay for itself in 15 years -- very similar to pay-back period of solar with the net-metering subsidy.

    It seems to me that this may be more of a discussion about what subsidies are available and the key is that solar subsidies are common. If subsidies for both were available then on the consumer side it could be a choice between DER's considerable fringe benefits or solar bling.

    On the utility side I could see subsidizing a DER as being more advantageous -- it is a one-time subsidy where as solar is a recurring subsidy and DERs predictably reduce peak load where as solar is unpredictable.

    I feel very lucky that our utility sponsored our DER and we had such an incredible design/build firm. I could not have done it without them.

  77. Dana1 | | #77

    It's not that simple (response to Chris Gleba #76)
    "Solar is viable with net metering but net metering is subsidy -- it is a free rental of a 100% efficient infinite battery. It costs the utility more then wholesale power."

    I'll try to disabuse you of some of these long held truisms that are simply no longer true.

    At $3:50/watt-pk the lifecycle cost of grid tied PV is below the residential retail rates for most of New England, using reasonable discount rates in a net present value calculation. I've seen recent quotes in that range. (With federal tax credits and other subsidies- notably the SREC production credit market, the lifecycle cost of even $4.50/watt PV comes in at a lifecycle per-kwh cost of about half the residential retail rate in MA.) It's widely presumed that the installed cost for rooftop grid-tied will be under $2/watt well before 2020- it already is in some locations, and would be financially viable without any tax or production credit subsidy.

    To date net metering is a subsidy to the UTILITY, not the residential PV owner, according to those who have studied it in depth. The value of the distributed solar to the utility is more than the offset of flat-rate kwh. The value comes in many forms, not the least of which is summertime peak power "purchased" at the residential rate rather than at peak spot market, which can be several times the residential retail rate. Also, PV output occurs primarily during demand hours, and by sourcing power locally on a grid branch, relieves grid congestion issues, and delays the requirement for investing more capital in to grid assets such as higher capacity conductors & substations, etc. Where regulators guarantee a profit on those capital upgrades it's not necessarily in the utility shareholder's interest to put off or eliminate those investments, but it is SURELY in the ratepayer's interest to avoid or defer those capitalization costs.

    The value of the distributed PV varies with both the local grid/utility economics & assets which will also vary over time. The utility in Austin Texas did a fairly rigorous valuation of the distributed PV to their grid and is now compensating PV owners at a "value of solar tariff" (VOST) that is, for now, higher than the residential retail rate. The state of Minnesota used that as the model for their developing their own VOST calculation methodology, which was approved by the state regulatory bodies in just the past few weeks. While net-metering is still allowed in MN, any changes to net metering MUST be made using the VOST methods. Strangely, the utilities aren't falling all over themselves to take back all of that "subsidy" they have been "giving" to distributed PV owners. :-) That's not to say that they won't ever opt to pay under a calculated VOST but under the current MN grid conditions the utilities would be paying more to the PV owners than they do under rough-justice net metering.

    Of course utilities lobbying to protect their long held business models continue to protest that net metering is a subsidy, and PV operators are freeloaders on the grid, and sometimes even winning concessions in the form of monthly fees for staying hooked up to the grid, but in truth those fees are a gouge- an attempt to strangle the PV-genie before it upsets their until-now comfortable tea-cart, since the PV is cutting into the capacity factor of their own peak generation and soon threatens to cut into baseload generator capacity factors in AZ and CA. The handwriting on the wall is in Germany, where utilities that recently bet on large centralized power generation are teetering into bankruptcy, and in some instances dismantling and selling (at a lost) even combined cycle gas plants at a discount to other countries where they might actually be used.

    Utilities have long been subsidized in many ways, but that's not to say it's a good idea for distributed PV owners to be subsidizing them for their shareholder's benefit. Utilities will have to adjust their business models to the new low cost PV reality or they're toast.

  78. user-757117 | | #78

    Response to Dana (# 71).
    I am not yet in a position to comment on the paper you cited earlier as I have only so far had time to read the abstract.
    I agree with many of the observations you are making, but for now I remain unconvinced that reduced electricity demand is primarily the result of (in a general sense) a more energy efficient economy.
    In some ways energy efficiency is probably making some difference, but in a globalized world, a more realistic accounting must factor in an understanding of global trade dynamics.

    For a more technical description of this perspective, please see the following paper on the "Material Footprint of Nations" (not long):

    In a nutshell, it describes an attempt at a new model for understanding some of these dynamics and that evaluating resource [energy] consumption for individual nations without consideration to their trade relationships with other nations provides an incomplete picture.
    Essentially, it is easy for a nation's economy to appear to be more energy efficient when other nations are doing the "heavy lifting" (ie, the more energy intensive activities of resource extraction and manufacturing) while the "more efficient" nation sticks to consuming the finished products.
    When energy (and other resources) embodied into products imported for consumption are reflected in the importing nation's energy (and other resource) balance sheets, the picture appears substantially different than if such factors are excluded from analysis.

    As far as dreams go (and what thoughts of the future aren't?), your dream is not a bad one.
    However, any dream can be come a liability if dedication to it stymies critical evaluation.
    In this vein, I would suggest that while continued effort at advancing energy efficiency and renewable energy programs is essential, so is the realization that they are not magic bullets since they fail to address the real underlying causes of a global predicament like climate change - ie, the human factors ("It's not us, it's just dirty and inefficient technology!" - not.).

    Excerpt from the above PNAS study:

    Humanity is using natural resources at a level never seen before. The total amount of 70 billion t of raw material extraction is unprecedented, and per-capita levels of resource consumption are at their highest level in history (10.5t/cap in 2008).

  79. lutro | | #79

    Thanks for explaining, Martin
    Thank you, Martin, for the answer to my question, which you provided in comment 75. Perhaps for those who are most concerned about passive survivability, there would be value in coming up with a way to use DC power from their PV panels, to power resistance heaters and other devices that are tolerant of voltage and current variations, during prolonged isolation from grid power. I'm guessing that there probably aren't too many people who would consider this.

  80. lutro | | #80

    Thanks, Dana, for comment 77.
    Thank you, Dana, for all your contributions to this thread (and others). The information that you provided in comment 77 is useful to me, both for my increased understanding, and for discussions going on in our local solar energy advocacy organization. I appreciate your taking the time to explain so thoroughly. Thanks to everyone else, as well.

  81. user-1102578 | | #81

    Response to D Dorsett #77
    Thanks Dana -- the Minnesota VOS methodology looks much more clear then most papers I have read on solar economics:

    Thanks for that tip . . .I'm going to let it sink in for a bit. . .

  82. JonathanTE | | #82

    First, a response to comment 72 asking for a quick summary that can be used as a sales pitch: "Lie to your clients." If you promise them that a DER will be financially advantageous, then some of them will believe you and go for it. They may never check the numbers, and so live in blissful ignorance ever after. Or they may get lucky and have low energy bills during the economic apocalypse of $300/barrel oil. Luck being relative, of course.

    Second: all this has inspired me to run some quick and dirty Excel calculations on measures done at my house. I've tallied up the heating oil purchased each heating season and divided that by the number of heating degree days in each season. When I first moved in, the house went through roughly 0.21 gallons of oil per HDD. This did not change one whit following replacement of numerous old single-pane windows with low-e, argon-filled double panes. However, replacement of the windows did liberate me (at no energy cost) from the minor labors of seasonal hanging of outdoor storm panes plus seasonal installation of window plastic on the interior. Plus they have less lead paint chipping off of them for my toddlers to eat, and are infinitely easier to clean (not that we ever clean them). Worth it? At this point it doesn't matter because it's a sunk cost, but for others considering the same thing, information to consider.

    After a few years living in the house we added a mudroom. It's conditioned, but kept at a low temperature and so functions as a semi-air lock between the outdoors and the true living space. This appears to have reduced oil/HDD by about 8.7% (down to 0.19 gallons/HDD). Subsequently we did a heating system overhaul. Half of the house was heated with steam. We eliminated the steam boiler and tied the radiators into the existing (approx. 15 yr. old) hot water boiler that already heated the other half of the house. The circulator was swapped for a Grunfoss variable speed pump, and an outdoor reset was added to the system. All this appears to have reduced our oil/HDD consumption by an additional 13.4% (down to 0.162 gallons/HDD).

    Subsequently, we insulated the basement, foaming over the rubble foundation/basement walls top to bottom. The basement is now the warmest, dryest room in the house (in winter)! Strangely, it appears not to have any effect on the heating efficiency of the house as a whole. I do plan to take advantage of all that waste heat by swapping our domestic hot water supply to a HPWH--currently our hot water is in a tank heated as a zone off of the boiler. I've gotten the advice to cut some holes in the basement ceiling and put in registers to the 1st floor, to allow the warm air to easily get up into the living space. I'm surprised it needs that, seeing as the floor can't possibly be air tight, but anyhow, seems like a harmless effort if nothing else. (except maybe annoying by allowing noise of the boiler to enter the living space. I plan to try to rig a sound baffle around the register if the noise is sufficiently annoying.)

    Additional weatherization in the plans: the second half of the house sits over crawlspace with sagging fiberglass batts (installed upside down). We'll be removing the batts and spray foaming around the perimeter, plus laying down vapor barrier on the dirt floor of the crawlspace. Also, though there is a fair bit of fluffy stuff in the attic, it was never air sealed so we will get up there and hit the leaky spots.

    After that, we'll take stock.

    Separately, I crunched the numbers from our home performance audit from a few years ago. According to that, we should avoid 1.79 lbs of CO2 emissions per year for each dollar invested in above-grade basement insulation (up to R-21). Various air-sealing around the house (doors, attic vents) is predicted to reduce CO2 by 0.87 lbs./year/dollar invested. If someone is thinking about doing a DER, what kind of numbers are predicted for that, for each element of the DER? If you start getting down to 0.05 lbs CO2 avoided per year per dollar, you have to start wondering. Don't you? (See comment 4.)

  83. Expert Member
    Dana Dorsett | | #83

    Response to multiples
    #81 Chris Gleba: There is pretty wide consensus amongst analysts that distributed PV doesn't start to add cost to the grid operator until it has become about 15% of all annual power going onto the system. Parts of Hawaii they have blown by that number and still climbing- in some already saturated neighborhoods the mid-day PV is exceeding 100% of the local load and backfeeding onto local grid assets not well suited for and not designed for 2-way power traffic. Ambri will be field- testing their scalable liquid metal grid storage in Hawaii first at a wind farm, whose output is less well timed to load averages or the aggregate PV output, making it potentially problematic, but it's scalable down to the single house level if need be.( see: ) In those heavy PV neighborhoods they are imposing a somewhat-onerous fee for any NEW PV going onto that very localized grid, while they are working out the details on how to fairly apportion the necessary grid upgrading costs. But as the cost of scalable/controllable storage crashes it will likely become the cheapest solution. California is anticipating hitting those renewable saturation levels in many areas before 2020, and has mandated grid storage as a means of managing a higher level of intermittent renewables, with the costs falling mostly to the rate-payers at large.

    There is discussion of adjusting regulations to allow distributed localized storage for distributed PV operators and paying for power at spot-market, but that has been resisted by utilities who are reluctant to allow PV operators to charge their storage at off-peak rates only to sell the power back a peak rates. That resistance is a bit mis-placed IMHO, since allowing that to happen would both raise the off-peak baseload price (and capacity factor), while reducing the price of peak power. The stakeholder that really loses in that scenario would be the owner/operators of low-efficiency low capacity-factor peak generation assets, but in the dawning age of cheaper grid storage they're already doomed, no matter which side of the meter the grid storage lives on.

    #78 Lucas Durand: I totally get that the globalized economy can ship carbon footprint and other issues offshore and give the appearance of a greener economy, and that there is no simple accounting for what constitutes an "energy-efficient economy.". But manufacturing has picked up in the US along with the economy in recent years without driving up electricity demand broadly, even though the analysis in that previously linked to white paper indicates that demand in the industrial sector is increasing with the uptick in the economy. In the ERCOT (mostly Texas) region overall electricity demand is continuing to rise, while the capacity factors of fossil fired baseload generation has continued to fall, in large part due to the explosive growth of wind power (which will soon be overtaken by even cheaper PV output) in Texas.

    No, there is no technology panacea in the wings, and yes, the needle on efficiency needs to move a LONG way to "solve the problem". But the argument that distributed renewable power is unaffordable is being blown away by facts on the ground, and will be even more so as fossil extraction continues to become more expensive. The rationale for fossil extraction is poised to go away, or at least become dramatically reduced. I'm not sure who said it first, but the stone age didn't end because the world ran out of stones, and that will be the case with fossil fuels.

    And in that regard...

    #82 Jonathan Teller-Elsberg: "Or they may get lucky and have low energy bills during the economic apocalypse of $300/barrel oil." I'm reluctant to ever say "never", but $300/bbl oil seems highly unlikely, since at that price nobody would buy it- EVERYTHING becomes cheaper.

    While this isn't universally true just yet reducing your own carbon footprint it's probably cheaper to just stop burning #2 heating oil for space heating and use heat pumps. At the ISO-New England heating-season grid mix a heat pump with an average COP of 2.5 has less than half the carbon footprint of condensing gas furnaces, will be even better after already-scheduled coal plants closings are history. An 85% oil burner puts out more than 50% more carbon than a 95% condensing gas burner to deliver the same heat to the house- heat pumps make an even bigger impact when displacing oil fired heat. In terms of carbon bang/buck there are situations where spending the money on switching over to heat pumps from oil are much better than spending it on a DER for marginal oil-use reductions. That will of course vary with your local grid. But of course, until the grid is substantially greener the DER will still be necessary to hit the 80% below 1990 carbon output targets: See:

    Even at $100/bbl crude oil & 20 cent/kwh power it's still quite a bit cheaper to heat your place with heat pumps, and the cost savings of the displaced oil use can fund the DER.

  84. Expert Member
    Dana Dorsett | | #84

    Ducted heat pumps work too.
    It really depends on how cold your climate is but there are some pretty good mid-tonnage modulating ducted heat pumps that can work for the doored-off antique homes that can work OK in much of US climate zone 5, such as the Trane XP25, or Carrier Greenspeed.

    I know some peops who installed a 4 ton 3-zone Trane in their 18th century added-onto in the 19th and early 20th century house in a location with an outside design temp of -2F. Since they ran most of the ducts and the air handler in the attic the as-installed as-used efficiency isn't nearly as good as a ductless approach, but still cheaper to heat with than their late 1990s oil boiler. (And with 8-10kwh of ground mounted PV in their backyard they had an electricity-surplus issue to deal with, since under the net-metering deal with the utility they were not being compensated for the annual overage they were sourcing. The heat pump fixed THAT problem BIG TIME ! :-) )

  85. user-705006 | | #85

    DER price tag of $100,000 - really?
    Martin floated the $100,000 cost for a DER, which is indeed expensive. But I have the suspicion that this number doesn’t tell the whole story, and it looks like I am not the only one having questions.

    William Goodwin (#26) points out that:

    “…houses with unattractive, failing, lead paint covered or asbestos exterior finishes might be candidates for a deep energy retrofit in conjunction with an exterior remodel.”

    Thinking along the same line, Bob Irving (#28) asks:

    “…the real question needs to be: what is the additional cost to add insulation to the envelope?”

    That question got never answered – although Chris Gleba (#76) got somewhat close:

    “…the marginal cost of going from building code to DER (we needed a new roof, new siding, basement work, and an addition either way) will pay for itself in 15 years…”

    I would agree that spending $100,000 on a DER on a move in ready home with no or little deferred maintenance doesn’t make sense, but weatherization would.

    But there are also buildings like ours: A 110 year energy hog – a masonry two flat in Chicago with decades and decades of deferred maintenance ( Unfortunately, our building is not an exception. Do I really want to start weatherizing buildings like this? I think weatherization in these cases would be money down the drain and merely compound the problems of deferred maintenance.

    It typically requires a gut-rehab to bring these building up to basic code and make them once more healthy and safe to live in. At this point, I would argue that a DER would be worthwhile considering.

    Let’s stick with the suggested $100,000 price tag. With the above scenario, I would need to subtract all the work that I would need to do anyways to put the building back into basic shape. At this point I am potentially going from $100,000 down to incremental extra cost for the DER. And – may be – it turns out that a “shallow energy retrofit (SER)” would do the job, particularly if cheap solar would allow me to go from R40 down to R30…

    I like this provocative post by Martin and thoroughly enjoyed the discussion in the comment section. What a treasure trove.

  86. JonathanTE | | #86

    Re: Dana #83 (heat pump v. insulation)
    Yes, I've got that in mind too. My house has a cruddy layout for heat pumps--a long, skinny farmhouse with lots of small rooms. The part of the house that we spend the most time in already has a small wood stove, so that space and the room above it have much-reduced demand on the oil boiler. (It and the bedroom above it each have their own thermostats. Other parts of the house have independent thermostats.) So I dunno... I'll have to do some more analysis to figure out what'll work best 'n such.

    UPDATE: to be clear, nothing I'm doing on the weatherization side approaches DER. Just good old weatherization. No existing plans to swaddle the walls in polyiso or whatever.

    UPDATE: I'm in climate zone 6.

  87. user-757117 | | #87

    Response to Dana (#83)
    As I have said a couple of times now, I agree with your observations about the cost competitiveness of distributed renewables - I don't dispute that.
    And I don't dispute that this has been creating disruption in energy markets.
    However, when you say the "rationale for fossil extraction is poised to go away" I am not-so-sure - but I agree it sounds pretty good in theory.
    History will show us just how "rational" the marketplace will be when push really comes to shove (or maybe more accurately what rationale determines the future of fossil fuel production) - but until then, whether this or that WILL happen is really just a matter of faith.
    And of course the stone age didn't end for lack of stones, but at the risk of stating the obvious, this ain't the stone age.

    These days we have a great heap of uncertainty, and under such circumstances prudence suggests a precautionary approach to the future.
    Rather than just leaving our collective fate to faith in market forces, we could also attempt to "look in the mirror" and address those real fundamental drivers of climate change.
    For just one example, we could ask ourselves if the cultural story (it is only just a story after all) that tells us that we should create demand for stuff (a behaviour which we know is responsible for putting vast quantities of CO2 into the atmosphere, even if a lot of it happens on the other side of the globe) is really a story we want to listen to and live by anymore.

    But I know, I know, this is not a very likely...
    And so we risk being the monkey, tightly gripping the banana inside the gourd, even as the hunter brings down his club (or maybe Homer Simpson tightly gripping a soda can inside a vending machine).

    In any case, I sense an impasse in this debate - we can just agree to disagree on ideological grounds.

  88. GBA Editor
    Martin Holladay | | #88

    Response to Marcus de la fleur
    You aren't the first person to question whether a deep energy retrofit really costs $100,000. Many observers point out that you should be able to back out the cost of the new siding and roofing, since these are non-energy-related amenities.

    Even researchers who have tried to back out these non-energy-related costs have still ended up with costs in the $80,000 to $150,000 range. The fact is, critics like to imagine the perfect building for a deep energy retrofit, and then generalize from the perfect building. Researchers and remodelers working in the real world, however, have to work with buildings as they actually are, not hypothetical buildings.

    For more data on the cost of deep-energy retrofits, see The High Cost of Deep-Energy Retrofits.

    There are several problems with your suggestion that builders can achieve lower deep energy retrofit costs by focusing on "110-year-old energy hogs ... with decades and decades of deferred maintenance." The basic problem with this cost-reduction strategy is that these buildings have more rather than fewer problems to address. Fixing all of the issues in this type of building, and making sure that life safety issues, electrical code issues, plumbing code issues, and basement moisture entry issues are addressed is extremely expensive. Sure, you can back out all of these costs from your analysis -- but (a) you can't build an affordable carbon-reduction program on this strategy, and (b) you might as well just build a new house if you need to do this type of gut-rehab work.

    In his presentation, Paul Endrenkamp pointed out that even his very high costs included a flaw: he wasn't charging enough for his work. "The gross profit on my first deep energy retrofit was -$2,000. That's right -- it was less than zero." Everyone, including well-meaning builders, really wants these types of jobs to be affordable. They're not.

  89. user-982477 | | #89

    Sun vs. Water
    Bravo, Martin, on another awesome story. And so interesting to read all the comments, too. The best reading on the web this week!

    Seems to me that those who have sun don't have water, and those who have water don't have sun. Maybe would could trade and live happily ever after.

  90. GBA Editor
    Martin Holladay | | #90

    Response to Pam Kueber
    Thanks for the feedback.

    By the way, Mississippi and Alabama have high rates of rainfall and high rates of insolation. If you want both water and sun, you should move to Mississippi or Alabama.

  91. Expert Member
    Dana Dorsett | | #91

    Response to Lucas Durand (#87) I'm not sure we disagree
    We may be just talking about different aspects more than simply oppositional. I too believe that there are natural limits to economic growth, but I'm less convinced that carbon emissions will be in lock step with the substantial amount of worldwide economic growth that IS going to happen over the next century, since PV and wind are rapidly becoming cheaper than the high-carb alternative.

    But it's true that most people don't really get just HOW cheap PV is going to become (or is already, compared to high-carb alternatives in the third world) and how that is going to change the picture of all-things-energy (particularly grid-energy in the Americas) in the coming 2 decades.

    Just last week David Crane, the CEO of NRG Inc (the largest independent power generation company with lots of fossil & nuke assets) made the statement:

    "The fact that distributed solar is going to take over the built environment in the United States, it's a completely foregone conclusion that that's going to happen."

    In the same Q & A session he also said:

    "The purpose of having old coal plants, to be frank, is keeping the lights on for the next three, five, 10 years,"

    Ten years isn't a very long time in utility company investment-cycle terms.

    His oft-quoted line of the day was:

    "I'm not anti-utilities, I'm not anti-nuclear, I'm not anti-coal, I'm just anti-bullshit."

    (More here: )

    This was a guy with vested interest in power generation reading the handwriting on the wall out loud- fossil power in the US is at it's zenith right now, even if the rate of the decline in fossil power is uncertain, the decline itself is. Only the folks drinkin' the frack water will say otherwise with any vehemence.

    Fixing developed world grid power won't solve the other material resource issues, and there are many less expected ways in which things might evolve, but neither enhanced efficiency nor distributed generation is a particularly sticky monkey trap, with a lot of depth left to tap to provide a continuation of economic growth. (By some analysts estimation something better than 80% of grid power in the industrial sector in the US is wasted, which is a pretty deep well to tap.) A goodly amount of both will be necessary, but both are in fact cheaper than "dig it up and burn it" strategies, when implemented using least-cost methods. It's only a matter of how much of each and when/how. In the US minimum efficiency standards work, and work economically, despite the squawking of the political right. But bece it's politically unpopular it continues to be underutilized.

    At this point it's cheaper to build distributed scalable renewables than a grid & centralized power system necessary to provide power to remote area in the developing world, even in places as densely populated as India, and it's cheaper power than the small scale low-efficiency diesel that it's is replacing and expanding on. (In some of those same places there isn't sufficient cooling water available to support massive grid development with thermal plants of any kind.)

    Whether it happens at a fast enough pace to make the critical difference isn't clear- but the cost of small and mid-scale renewable power is no longer the obstacle it was 20 years ago. SunEdison is now able to sell PV powered irrigation pumping systems in third world rural areas on a cost-savings basis, and PV powered lamps can be sold profitably with a signficant cost savings to the end user over kerosene & oil lamps- there is no reason to believe that China's high-carb path of the past 30 years of insane growth rates will be repeated in quite the same way. SunEdison founder Jigar Shah (a US-American from Chicago with a Hindustani name) was saying things along the line that "Third world government should just stop lying to the people about when they are going to bring the grid to their village, since that just stops them from buying their own solutions that take less money anyway. Aid money to developing countries for electrical power development is being largely wasted, since the way it gets spent is too influenced by the centralized grid mindset of those the donor countries." (paraphrased only). I'm somewhat hopeful that the mindset will change as grid power sources in the already-developed world becomes ever more distributed.

    For instance, Zimbabwe has a heluva lot of coal in the ground and but a handful of coal-fired central power plants. But even if they get their political problems in order there's no reason to believe it'll ever heavily tapped for coal energy, though coal-seam methane (for both chemical & energy purposes) may happen, provided the coal seams get more developed before local PV dominates in Africa the way it will elsewhere. There is at least one 300MW coal- methane power station planned but not yet under development in Lupane ZW, but it's not clear that it'll get built before it's simply not needed. Cost estimates for just building that plant are getting onto $2USD/watt, which is already about the cost of grid-tied PV that needs less distribution infrastructure and carries no fuel costs. ( The cheap & scalable grid battery problem is already well on the way to being solved- at the rate things really get done in Africa the whole scalable-renewable solution will be cheaper, and people will solve it themselves rather than waiting another decade or three for the central plant and wider grid to get built.

    One paradigm of at least some relevance is that many parts of the developing world that never had a wired telephone system now have well developed cellular services, and will NEVER have wired telephony. To be sure, electrical power is a bit different, it won't be an exact repeat- but you can be pretty sure that it's going to rhyme. The huge amount of infrastructure required for centralized power isn't a prerequisite for providing useful energy any more. The economies of scale that went along with large centralized coal-fired power generation in 1914 just aren't there for PV and mid-sized wind in 2014.

  92. user-757117 | | #92

    Response to Dana Dorsett
    Certainly these issues are complicated enough that it is easy to talk at cross-purposes.
    I agree that fossil fuel production and carbon emissions aren't necessarily destined to follow any particular growth trajectory (in fact, I think that these must decline "naturally" at some point with or without competition from cheap renewable energy).
    And if we can agree that there are natural limits to economic growth then you're probably right that we can't be too far apart ideologically.

    I will risk complicating this discussion further then by saying that I am skeptical that renewables will actually outcompete fossil fuels because of issues related to economic growth (just to be clear, I don't mean outcompete in the sense of cost/unit energy supplied to market as that appears to already be happening, but rather outcompete in the sense that they actually force fossil fuels out of the marketplace over the long term despite the relatively high cost of the latter).

    It seems clear that the projections you are describing are plausible and that we are seeing now the very first glimmers of such a possible future reality - but, like any forecast, those projections rely on some assumptions, the largest of which may be the assumption of continued economic growth and relative prosperity for the global economy (ie, continued build-out of renewable infrastructures requires stable financing typical of growing economies, trade and logistics for sourcing materials/components, etc).
    If we assume that natural limits to economic growth are still far enough away that, say, another 50 years of economic growth is not out of the question, then I think it is possible that the types of projections you describe may have some chance to come to pass.
    If, however, such limits are closer at hand (and it does seem entirely possible that they could be) then significant economic disruption may lead to any number of other alternative scenarios - including some in which human beings choose the "all of the above" option for energy (economic "hard times" could be a rationale for forcing the production of fossil fuels even where they are not cost competitive with renewables simply, say, to employ people or for strategic advantage).

    I am also skeptical that we (human beings) are as smart as we seem to be convinced we are (certainly as a species we are not very wise, in general, but I'm not sure we're quite as clever as we think either) and that the economic theories that have become the dominant cultural force on this planet are maybe not so correct as we think they are.
    By way of analogy:
    The other night I happened to be watching Neil deGrasse Tyson talk about how people's understanding of gravity has changed over the years, and how observations of the planet Mercury's orbit created some uncertainty about the Newtonian model which had worked so well up to then.
    Apparently, until Einstein came along with the theory of general relativity, Newtonian physicists were content to simply assume the existence of an unobserved (imaginary) planet "Vulcan" in order to explain the discrepancies between their observations of Mercury's orbit and what the Newtonian model predicted.

    I think that there is a very good chance that this exactly where we are now with respect to our understanding of how our economics interact with the "real world" (ie, the physical universe).
    For a long, long time economic theory could be applied in the "real world" without those theories being truly tested against certain large-scale physical limits (ie, limits to pollution (including CO2), limits to resources, etc.) in the same way that it took a couple of hundred years before Newton's laws were tested by a planet that refused to adhere to its predictions.
    Economist Herman Daly coined the terms "empty world" and "full world" as a general means of differentiating between two distinct contexts in which economic theory is applied - the economics that we know now evolved and have their track record in an "empty world" (empty of people but "boundless" resources) and now we will see a real time test of those economics in a "full world" (full of people and with diminished resources).
    Which theories will survive the test, which will have to be rethought?
    Should be interesting...

    But I refrain from making my own predictions, I just like to point out that there is a lot more uncertainty in the world these days than many people are generally aware of and so I advocate for a precautionary outlook - ie, until we know with more certainty what's what, it would be wise for us to slow right down.

  93. user-705006 | | #93

    Response to Martin Holladay

    (a) you can't build an affordable carbon-reduction program on this strategy

    Martin, is your emphasis here on "affordable" or "carbon-reduction"? I assume it is on affordable, but would like to be sure.

    (b) you might as well just build a new house if you need to do this type of gut-rehab work.

    I hear and read that all the time.

    I think we can agree that it can be extremely expensive to get these old energy hogs fixed up (DER or not). What I want to know is what you suggest to do with them instead – if not fixing. Letting them sit and continue to defer maintenance won't help. As we all know, deferred maintenance get exponentially more expensive over time and the buildings continue to be energy hogs. New construction won't solve the problem in a City like Chicago, unless you tear whole neighborhoods down and start over. Not sure that I would file that under viable or wise.

    In short: with all the options that come to my mind, fixing them up and at that point looking at executing a DER sounds like the best and pretty cost effective solution to me.

  94. GBA Editor
    Martin Holladay | | #94

    Response to Marcus de la fleur
    You quoted one of my comments -- "You can't build an affordable carbon-reduction program on this strategy" -- and then you asked, "Is your emphasis here on ‘affordable’ or ‘carbon-reduction’? I assume it is on affordable, but would like to be sure."

    If you mean to ask whether a deep energy retrofit reduces carbon emissions, then I would of course answer yes. But lots of measures reduce carbon emissions at a very high price; for example, if the federal government funded a car-swap program that provided a new Prius to anyone who agreed to surrender their existing car for crushing, the program would reduce carbon emissions. But it would be a very expensive program.

    You wrote, "I think we can agree that it can be extremely expensive to get these old energy hogs fixed up (DER or not). What I want to know is what you suggest to do with them instead – if not fixing?"

    That's a dilemma for the owners of these buildings. But it is conceivable that our new post-climate-change future will lead to many neighborhoods being abandoned. Predictions are tough to make. The brutal fact is that not every existing house is worth fixing up.

    If owners can afford a gut rehab of a building in terrible shape, then I salute them for doing the work.

  95. user882465 | | #95

    The Lock-In Concept
    Am I hallucinating, or does the email I received from Green Building Advisor have another story listed slightly above yours titled, "The ‘Lock-In’ Concept and Passivhaus Construction" that says: "It’s better to save up your money for a deep-energy retrofit in a few years than it is to implement less comprehensive measures now."? That article is at
    Is your blog post intended as counterpoint or is this just a strange coincidence?

    I agree with your post!

  96. GBA Editor
    Martin Holladay | | #96

    Response to Bill Burke
    "The ‘Lock-In’ Concept and Passivhaus Construction" is a guest blog written by Matthew O'Malia. GBA regularly publishes guest blogs, and our bloggers express varying opinions across a broad spectrum.

    GBA is delighted by this diversity of opinion, and makes no attempts, Stalinist or otherwise, to enforce conformity.

  97. danandmarcy | | #97

    Homeowner bewilderment and frustration
    The wife and I have been considering, for a good while now, our future options for energy-efficient living, and doing so in a manner that creates a "rest of our lives" home. We've decided this is the local area in which we wish to grow old and are now considering what it will take to do so. Accessibility is key, as are proximity and energy use. We're not eco-nuts, alarmists, or anything like that, but simply understand that fossil fuels do not grow on trees and that we're not creating enough dinosaurs to keep up with the demand for dino-oil.

    The approach to our goal (or at least the thinking) is multi-pronged: use less, generate some of our own, evaluate and act on some lifestyle elements, and make this our last home. We had originally planned to build new about 30 miles from here (but still somewhat local to the small city nearby). Last year we bought a pair of adjoining lots at a good price, with perfect southern exposure and easy (though a bit distant) access to the city. We were looking into building a single-story passive-type home with a large and separate building as a garage and shop space for my business. Ultimately, we've reached the 90% decision that the greater distance from the city could be problematic as our mobility declines with age. Well, that, plus the large price tag we've repeatedly seen for passive (whether certified 'passiv' or not). We've now put the build option on the back burner due to location and cost.

    That puts us, then, on a path to remodel the place we're in now. It's a classic 1920s Midwestern / Sears (not sure if it's an actual Sears home) foursquare, in good-but-not-great condition. The location could hardly be better, we're already here, and we think we can meet the needs of my business by doing a small expansion - including adding some space in the basement - and some carefully considered rearranging of the first floor layout. This would include expanding the garage to the village-maximum 1,000sf. Similar to the vacant lots, we have near-perfect Zone 6 (SW Wisconsin) southern exposure on both the house and garage.

    We've long considered solar (PV and water) to be a part of the formula. The sun is working 24/7 around the world (literally!) to give us a source for warmth, and through clever science and engineering, electricity. All for the cost of some hardware with few - or no - moving parts. Obviously it's not a 100% solution; sunset makes that the reality. Batteries have been considered by the wife and I but there are some problems with that (cost, space required, putting them in a climate-controlled space, off-gassing, etc.); we haven't given up on that detail but it's also firmly on the back burner.

    That still leaves the consumption side. We're currently addressing that by keeping the thermostat low in winter, to the point that I wear thermals each day from around November through March. And working in the basement often has me wearing a jacket - some mornings this past colder-than-normal winter it was 42-45 degrees down there. Our consumption is certainly lower than it could be were the thermostat set at 68-70 instead of the current 62-64 for heat and 74-76 for cooling. The bills are low for a house this size in this zone, but only because we've essentially insulated ourselves for 5-6 months each year. Comfort is being sacrificed in the name of consumption, and we realize that is NOT going to work in retirement.

    I do have a point, and we're getting there...

    So we're leaning heavily toward making this home work for our goals. The roof is due for replacement in 3-5 years by my guesstimate, the detached garage needs to be rebuilt, the siding - besides being an ugly green - is old with an integrated masonite insulation layer (I think we all know about the masonite problems), and it's just plain drafty. And that basement - brrrr! Seems like a DER would be a good fit at this time, since we'd be attacking the major components anyway.

    Originally I was thinking of starting with the garage, making at 41' (length of southern exposure) x 24' and slapping solar up there right away. That would at least get the ball rolling with almost no interruption here in the house, would gain me some storage space for business stuff, would put a couple vehicles inside (potentially reducing winter warm-up time and subsequent fuel use), and would slow down the electric meter. It could also be done much sooner than the house, thus being finished before the solar subsidies (we think of it as a tax refund) go bye-bye.

    And then we'd attack the house with gusto.

    This is where we're reading so much conflicting information, and what may ultimately lead to "analysis paralysis". To start with, we're not made of money. Our 6-figure income gets whittled down to 5-figures by the time our 30%+ effective tax rate kicks in. We're in the bad spot of not making enough to where money isn't an issue, and making so much that the meager subsidies are the only financial incentives available; we don't qualify for any "assistance" programs (in quotes, because we're funding with that 30%+ effective tax rate those programs that we, ourselves, don't actually qualify for). If money were no object I wouldn't be bothering with this post. But it is, so here we are.

    But conflicting information? Oh, yes:

    - "DER is the way to go to reduce your consumption. Ignore the fact that $100k is a fair guess of what it will cost. If you're supremely lucky and live in the right location, someone else will be paying for it." We're not lucky. "You'll start saving right away." Maybe. "The products are very durable." They incorporate toxic materials and manufacturing practices, and if they're not installed properly then they may as well not be installed at all. "You can reduce heating and cooling costs by up to 90%!" Sure, if you double that $100k. For which you'll never see the payback, let alone the original $100k. "Air sealing is paramount to making it work." That's wonderful, if you want Sick Building Syndrome because your consultant / architect / contractor doesn't know how to correctly address ventilation matters in this type of building upgrade. And the ventilation equipment will cost at least 2-3x as much as your plain ol' gas furnace does. Have you priced an HRV, let alone found someone who knows how to correctly configure and install one?

    - "Forget going crazy on energy-use reduction: renewable energy generation is the way to go." Got enough roof space? "Prices are coming down, making it more affordable." Essentially, you're getting some of your tax money back with the subsidies. And you better hurry up because the subsidies are expiring within the next 30 months. "They quietly and cleanly generate electricity and hot water." Until you consider the manufacturing process, and then you're trading power plant pollution for manufacturing pollution. "They last a good 20-30 years." With diminishing efficiency from Day One. And those panel will last 20-30 years while a correctly-performed DER is good for much longer than that. If you buy panels twice over 40 years, is it still cheaper than a DER? "Sure, you don't generate power all day long. That's what the grid is for." True, though grid-tie costs more upfront, and your power company is likely lobbying hard to buy your solar power at the wholesale rate, not the retail rate. And they'll win that fight as more and more solar comes online and their revenue declines. Because, well, lobbyists and politicians. That increases your payback period. "You can have a battery system instead of using the grid, then." Batteries are very expensive, they contain toxic materials, they require regular maintenance, they have a lifespan of maybe 5-8 years at which point you're replacing them all over again, you have to pay to dispose of the old ones, they can't be expected to work well in an unconditioned garage, and they will off-gas some pretty hazardous fumes.

    - "Just do weatherization." Okay, but we're tearing up all this stuff anyway so why not go farther? "Because you won't save that much." But isn't it better to pay once for the upgrades instead of paying every month the cost of NOT doing the upgrades? "It'll take forever to pay it back." Not forever. There's an actual date, and it's anyone's guess when that date will be. "So you don't know." Yes, we don't know. Does this mean that doing less is the right move?

    - "Well, you have to do SOMEthing, because fossil fuels, environment, etc., etc." Okay, here's my house, and here's what we'd like to accomplish. Give us an idea of what we should be doing. "You should definitely go with DER." "Oh, no. DER is stupid. Solar is the way to go." "No, those are both stupid. Shallow is the way to go and don't fret the rest." "These three are all wrong, and at the same time they're all right - you need to do a combo of all three!" Great. While you guys are arguing about it we're going to do nothing, which helps nothing. Also costs us nothing and requires no effort.

    So the solution is probably somewhere in the middle. Where in the middle?

    On top of this, "comfort" has been poo-pooed here in the comments by some of those in-the-know. As I have been working in our chilly basement, I have a pretty good idea of what is NOT comfortable: too cold, too hot, too humid, too dry, drafty, noisy, etc. We've done the thermals thing, the box fan thing, the window air conditioner thing. It gets old, fast, but we can live with it for now. When we're 70? 80? So don't discount the notion of comfort: just because it's no big deal to someone now, that doesn't mean it won't matter in later years.

    So why are we bewildered and frustrated? Conflicting advice from experts. We're told to do and not do DER. We're told to do and not do solar (especially hot water / hydronic, lately, for some reason). We're told that comfort is important, and also that it's overrated. We've even seen an article that almost-but-not-quite says 'do nothing' with regards to solar and DER:

    Shoot, we've even seen an article ( that says, "Step 1 - Upgrade the mechanical systems"... and later, "Note to item 5: Go back to Step 1 and reduce the size of the mechanicals.." The expert advice is to upgrade this stuff twice in the span of a few years?!? What am I missing here, besides a checkbook with a much larger balance? "After you get past item 5, the house will be efficient enough to downsize the mechanical equipment, which you replaced in step 1. If you’re planning to go at least through step 5, keep that in mind before buying a new boiler or HVAC unit. " We did keep that in mind, and decided that replacing nearly-new HVAC equipment with brand-new smaller HVAC equipment is some really bad advice. Unless, of course, you're an HVAC installer or manufacturer, in which case it's the best advice ever.

    Which expert is the correct one, the one with the right answers, the one that isn't going to cost us a ton of money that we don't have because we're paying taxes in part for energy efficiency subsidies for other people and other businesses, the one who doesn't have a favorite solution toward which he or she steers everyone regardless of whether it's the proper approach for a specific building? Who is the general contractor who knows the proper way to seal and insulate a building while eliminating the hazards of trapped moisture and dead air ("Houses need to breathe!" "Oh, no, they don't!" ), and can do this with products that have a smaller production and transportation impact? Who is the HVAC guy who knows how to size, install, program, and repair the costly HRV and ductwork that we've been told to buy because the house is now sealed tight as a drum? Who is the renewable energy guru who can make solar hot water actually work like it's supposed to (for some reason, we've read of many problems here), and also correctly combine it with the heat exchanger to reduce energy consumption further? Who is the person who can guide us through the various programs to help pay for this stuff that we're funding? And who can help us find a lender that understands what it is that we're trying to accomplish, and why it's adding value to the property?

    From what we can tell every opinion on the matter is right, and is also wrong at the same time. We're told, as consumers, to 'do our homework'. As we're doing that, we're starting to believe that nobody really knows what to do. "But every case is different." Well, yes, and no. As a consumer ultimately paying for - and living with - the results this can create a "do nothing" attitude, and maybe the easiest and overall eco-friendliest thing to do is to simply turn up the thermostat in winter. Sounds cheaper and less stressful but that doesn't lead to any solutions.

    I don't know if this is supposed to be a rant, or a lament. The problem for the consumers is that we're taking the single largest investment - our homes - and considering investing half again - or more - to make it operate more efficiently. A noble idea, and hopefully it has a reasonable payback. The difficulty is that looking at as much expertise / opinion as we can find, we aren't any further along on deciding what to do: deep, shallow, or medium? Generate our own juice or put that money toward the shell? If solar, how much? 3kW, 6kW, 10kW? Insulate, seal, or both? Tight shell vs 'breathing'?Are R-5 windows worth the cost, even if you're already replacing windows anyway? Solar hot water and hydronic heat - worth the cost and added complexity? Get rid of natural gas and go with an electric / heat exchange solution (CO reduction)? Batteries or not?

    And how do we find the experts to consult, design, and build, and install all of this stuff correctly, the first time, so we achieve those goals at the lowest reasonable costs and with the lowest overall impact, including manufacturing, transport, etc.? We are finding people who are involved in this stuff (not so much local), but, again, there is so much conflicting advice and data...

    I can't imagine we're the only consumers who are lost on what to do, and who don't know what to believe. For us, the more we research the more confusing it all becomes. "What's your budget?" "Don't know: how much will a lender spot us for energy efficiency (that's a 'chicken-and-egg' in itself), how much will it cost to achieve xx% energy-use reduction, how much will utility rates rise over any given period, how long will the subsidies be in effect, will new subsidies be introduced, will building codes change significantly, will we be able to find local consulting / design / construction / systems experts?" That's all on top of the questions and arguments stated earlier. We'll continue to research and hopefully the optimal solution will present itself - a combination of MER and solar, perhaps. And maybe it's best to simply close our eyes, bite the bullet, and not second-guess afterward.

    If anyone can offer sound advice on how to approach the thought process to help us clarify a direction in this bewildering process, we're all ears. We've made our lists of wants and needs for every bit of the property, so at least we have clarity on what we want to achieve, and we have a budget in mind (financing-dependent) to start with.

  98. GBA Editor
    Martin Holladay | | #98

    Response to Dan and Marcy Hudzinski
    Dan and Marcy,
    I understand your frustration, but I think your situation isn't as complicated as you imply.

    You aren't millionaires. You have a budget. Right away, that limits your options.

    You want a little more space in your garage, and you want to remodel your house. So you probably need to hire an architect or a designer. Hire one with a demonstrated focus on energy efficiency.

    Tell your architect what your budget is. That will limit a lot of options right away.

    If the architect is any good, he or she will recommend that you hire a RESNET-certified or BPI-certified rater to conduct an energy audit of your house. The cost of the audit will be worth every penny. You'll learn a lot about your house from the audit, and will be given recommendations for cost-effective energy retrofit measures that you can pursue.

    During the next few weeks or months, continue to read more articles on GBA, including the posted comments. The advice on this site is almost always dependable, especially when modified by the comments, and is only rarely contradictory.

    If you follow all these steps, you'll be well on your way to success. At that point, you can post any remaining questions on our Q&A page. Good luck.

  99. danandmarcy | | #99

    Been looking for raters
    Yep, we've been to both of those sites. For some reason, we're in this black hole where the nearest raters are quite a distance away. Not sure why since our metro area is in the 70-100,000 population range. Go figure. The RESNET site, for some reason, lists raters but doesn't provide contact info except for the Gold Star certified folks, while the BPI site keeps pointing me to people 1,000+ miles away when I specify my own region. Maybe some bugs on those sites.

    We'll keep looking, though - EnergyStar and FocusOnEnergy (WI's energy program) have their own lists of experts, so something will pop up. I have a feeling that matters will start to become clearer as we get some one-on-one time with those who know these things. But it would be nice to hear some industry consensus on one or two matters, anyway. Guess it's not that simple.

    One nice thing about the whole process - even though it can add confusion - is that there ARE different options to pursue. One-size fits-all is usually more like one-size-fits-none. As mentioned previously, it will eventually be a combination of power gen on-site along with some insulation and sealing, taking advantage of natural heat from the sun, and ventilation upgrades. I think that last is going to be unavoidable since we'd like to get to the point of a single fuel (the electron) for all of our needs. Eliminating combustion hardware inside the home increases long-term safety in a few ways.

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