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Building Matters

The Flip Side of Going All-Electric

The decision may be more complicated than you think

Photo courtesy of Energy Vanguard

Among green building advocates, the trend today is to “go all-electric,” meaning eliminate natural gas and instead use electricity for all of our domestic energy needs. It strikes me that Green Building Advisor supports this mission. In the article “Electrifying Buildings for Decarbonization,” the authors state “. . . electrification is a lower-cost and lower-carbon solution than extending natural gas service, either to new or existing homes.” Another article, “The Best Reason to Have an All-Electric Home,” by Allison Bailes says, “When you have to make a choice between electricity or natural gas, it’s clear that electricity is better for the environment and maybe for your checkbook too.” Contributor Scott Gibson reinforced the message recently in his piece, “Going All-Electric,” saying, “Weaning households off natural gas, heating oil, and other fossil fuels would mean significant reductions in carbon emissions. . .”

This case against natural gas simply isn’t true. Here I will highlight data on emissions from the power generation industry that use a variety of sources to generate electricity. In my analysis, it is too early in the process of greening the electrical grid to make such broad claims.

What happens when we eliminate natural gas and instead plug everything into the wall? Where does the electricity come from, and what are its environmental and health care costs?

I was curious to find the answers. While I’m instinctively skeptical of broad proclamations, I try to approach this sort of information without bias. (I should note that I want the electrical grid to be a greener alternative to natural gas!) I am not an advocate of unfettered free markets, but neither do I believe that the world can be saved by good intentions that are not manifested in rational, data-driven policy.

Conventional vs. electric

Our electrical grid is greening by the month, with increasing no-carbon renewable energy sources such as solar and wind. We are told that a net-zero carbon grid is within our reach by midcentury. Such optimistic projections depend on a lot of things coming together, one of which is the elimination of coal from the energy mix. (West Virginia is the second largest coal producing state—behind Wyoming. In a U.S. Senate that is a 50-50 split. Guess who has a lot of influence? Conservative Dem. Senator Joe Manchin of West Virginia. Coal is not going away anytime soon. Lots of money will be spent on carbon sequestration and other “clean coal” initiatives, even as the cost of renewable energy decreases.) In my analysis, that is the major challenge. Until we greatly reduce coal usage, beyond where we are now, it may be beneficial to continue to burn natural gas as an alternative to going all-electric. So at what point does going all-electric make sense?

Advocates of going all-electric focus on carbon emissions and their global warming potential, but this is not the sole consideration. In addition to CO2 emissions, burning fossil fuels emit substances that are harmful to human and environmental health. It’s important to consider the sources of greenhouse gases and other pollutants. Coal releases toxicants such as oxides of sulfur and nitrogen, particulate matter, and heavy metals. Mining coal comes at severe environmental costs, and coal combustion products such as fly ash must be buried or processed for commercial uses. Drilling for and burning natural gas is cleaner, with substantially lower sulfur dioxide, particulate, and heavy metal emissions. Additionally, natural gas combustion releases about half the CO2 emissions as coal. In 2019, coal supplied 27% of the total energy for the U.S. electric power sector, while natural gas supplied 31%. However, coal burning generated 60% of CO2 emissions, while natural gas generated 38%. (See the 2019 Estimated U.S. Energy Consumption flow chart from Lawrence Livermore National Laboratory.)

Looking at the source

Let’s look more closely at regional electricity generation in the U.S. I am in no way an expert on the complexities of grid-based electricity and its supply/demand dynamics, but there are two main—well, three if you count Texas—interconnected grids that supply the eastern and western parts of the contiguous United States. All the electrical production within these entities is tied together during normal operations, so for purposes here, I assume that over the course of a year, one’s base energy needs are met by the pooled outputs within one of these two entities. (You can get more specific data on electrical generation based on your area code here, and I would encourage you to do this.) For simplicity and brevity, I’m considering only the larger entities.

The Western Interconnection is overseen by the Western Electricity Coordinating Council (WECC), while the Eastern Interconnection is overseen by several regional councils. Electricity generation data is available for all North American Regional Councils (NERCs). Let’s look at some details. Data exist for 2019; data for 2020 are forthcoming. The data given here are taken from the EPA, which presents them in an accessible graphical and tabular form called eGrid. Data discussed here are presented in the Table below.

U.S. power generation and emissions chart
U.S. power generation and emissions


Of the 4140 million MWh generated in the U.S. in 2019, the WECC generated 739 or about 18%. Of these, about 39% were generated from renewable resources, making this by far the greener grid. Here it seems like a no brainer to go all-electric, right? But while renewables contribute a substantial amount, 20% of the energy still comes from the burning of coal, while 32% comes from natural gas. The EPA lists output emissions for the different sources of generation. Results are presented as pounds of pollutant per MWh electricity generated from the specified source. Let’s compare total output emissions with those attributable to natural gas alone. Even for this greenest of grid sources, total CO2 emissions, though less than, were still comparable (85%) to the emissions attributable solely to natural gas. NOx were about the same, while natural gas emitted far less SO2 (3% of total) and methane (CH4, 26% of total).

For the Eastern Interconnection, I’ve pooled the outputs of 4 NERC regions, collectively generating 2950 million MWh in 2019 (71% of U.S. total). Renewables represent 12% of the total. As expected, toxic emissions exceed those of the Western Interconnection on a normalized basis (see table). Notably, total CO2 emissions from the Eastern regions are 908 lb./MWh, with 896 lb./MWh coming from natural gas. The SO2 and CH4 contributions from natural gas were substantially less than from the total mix.

Consider CO2. The EPA reports 906 lb./MWh for the natural gas component in the Western Interconnection, and 895 in the Eastern. These amounts seem to violate the law of mass balance. If every carbon atom of natural gas were converted to CO2, the total would be 400 lb./MWh. A not commonly known fact is that two thirds of the total electricity produced in the U.S. is “rejected”. Rejected energy is that which is lost through waste heat; it includes the energy needed to generate electricity at the power plant, as well as transmission and distribution losses. The excess CO2 production over 400 lb./MWh is attributable to this rejected energy. On the other hand, just about all the natural gas produced and delivered to the home is efficiently burned and utilized. Natural gas is extracted from wells and distributed through pipelines. According to the Inventory of U.S. Greenhouse Gas Emissions and Sinks, in 2019, 1.3% of total extracted natural gas was vented or flared at the well site, and this represented an abnormally high amount. Another oft-cited source of greenhouse gas emissions from natural gas, in the form of methane, occurs from losses from transmission pipelines. 

An EPA study estimated that .401Tg are released annually.8 (A Tg or teragram is a lot…one billion kg, or 2.2 billion pounds.) Let’s view it in context. The U.S. produced 32.1 Quads (quadrillion BTU’s) of energy from natural gas in 2019, for all uses. The transmission loss of .401Tg comes to .094lb. of methane per MWh of energy. If we say that methane has a 25-fold greater greenhouse effect than CO2, this would come to an additional 2.35 lb./MWh equivalent CO2—not much in the larger scheme.

So which is really greener?

So being conservative, it seems reasonable to attribute no more than 450lb./MWh of CO2 from home heating and other domestic natural gas consumption. Now it appears that even the carbon balance of residential natural gas is “greener” than grid electricity from the Western Interconnection, even with 39% of the energy coming from renewables.

I recognize that these numbers are not cut and dry. For example, if you use an air-source heat pump, your energy in the form of heat from the unit exceeds your energy input from electricity by a factor called the coefficient of performance (COP). No, it’s not magic; the heat pump moves heat but doesn’t create it. A really great heat pump, such as the Fujitsu Halcyon RLS3HY non-ducted minisplit, has an ASHP-rated COP of 4.59 running at its rated output of 18,000 BTU/h at 47oF. Unfortunately, as it gets colder, the COP diminishes substantially. At 5oF running at maximum capacity, the COP is 2.07. Based on the data presented here, a COP of 2 or more seems like a realistic point where electricity may start to become a better option than an efficient natural gas furnace. For a range or stovetop, and for traditional (non-heat-pump-powered) hot water, natural gas remains a greener option than electricity.

You may or may not be concerned with out-of-pocket costs. In my Zone 5 area of cheap natural gas in the Appalachian foothills, I would need a COP of 4 as a financial break-even point to go with electric heat. I personally would pay the extra cost if the electrical grid were cleaner. We get our electricity from the ReliabilityFirst Corporation (RFC) west region, which produced 532 million MWh in 2019. Renewables contributed less than 4% of that, while coal supplied 44%. Toxic emissions exceeded national averages. In particular, CO2 emissions were 1166lb./MWh. Is anyone seriously going to tell me that electricity is a greener option compared with natural gas? Most people don’t have the luxury of entertaining such decisions. Are we really going to tell them that they can no longer have natural gas because of dubious claims about the relative cleanliness of the electrical grid—especially considering outrageously high heat pump installation costs detailed many times here on GBA?

Others have pointed out dangers of having a combustion device in the house, and of health hazards related to natural gas combustion products. I have not considered these hazards, as they are quite simple to mitigate . . . make sure it’s installed properly; make sure your stovetop is vented.

The contribution of renewable resources to the electricity grid is growing. Led by increases in wind and solar, early estimates are that renewables contributed 20% to the grid in 2020, up from 18% in 2019 and 17% in 2018. Frankly, increasing renewables by 2% of the total each year will not suffice. On the other hand, offshore wind represents a vast resource that is only beginning to be tapped. The development of utility-scale storage will decrease the amount of rejected energy. As these contributions increase, electricity will become cleaner than natural gas. In my evaluation, most regions of the country simply are not yet there. 

These are my opinions. Yours may differ but here is what I’ve concluded:

  • For existing homes that currently have a natural gas hookup, I would not yet cut the line. As the grid incorporates more renewable sources, and if these displace the use of coal (so far, the main coal replacement is, you guessed it, natural gas), then I would reevaluate at the end of service life of my furnace.
  • If I were building a new home, I would consider going all-electric, but only because of assurances that the grid will become sufficiently green at some point in the near future. I would investigate the electricity sources in my region, and I would consider special interests and political forces at work that may slow progress in the incorporation of renewables. Clearly, the decision is not as simple as others here and elsewhere would have us believe.
  • As a matter of national policy, I strongly disagree with prohibiting natural gas hookups in new construction. Good intentions, bad outcomes.


Fred Frasch is a retired scientist who worked over 20 years at the National Institute for Occupational Safety and Health. His interest in green building principles began with his retirement project of building a home in the Appalachian Mountains of West Virginia.


  1. CollieGuy | | #1

    So far this winter, our home's estimated space heating demand is a little over 14,000 kWh(e), virtually all of which has been met by our two, thirteen year old, mid-efficiency ductless mini-splits (9.3 HSPF). Their combined usage for the period spanning 01 October through to today is 3,843 kWh; in effect, for every one kWh that they've consumed, we've received over three and a half kWh(e) of heat in return (we did use 31.3 litres of fuel oil this winter, mostly to exercise our boiler so to keep it in good working order).

    At the moment, 70 per cent of the electricity generated in our province is produced through the burning of fossil fuels, primarily coal and petcoke ― Nova Scotia Power's overall generation mix in 2019 stood at 0.63 kg CO2(e) per kWh. Later this year, once the Muskrat Falls hydro-electric development is fully operational and we begin importing power from neighbouring Newfoundland and Labrador, and as we further develop our own in-province resources, that will be cut in half. For now, I pay an extra 2-cents per kWh for 100 per cent renewable energy to offset all of our home's needs.

    Natural gas isn't available in our neighbourhood, but at current rates it would be twice as costly to heat our home with gas as it would electricity.

    1. user-723121 | | #8

      These are fabulous efficiency numbers, what is the design temperature heat loss for your home?

      1. CollieGuy | | #11

        Based upon our boiler's fuel-oil consumption as our sole heat source over a two week test period, I estimate our home's average heat loss at 0.21 kW per °C whenever outside temperatures fall below 15°C (53-year old, 2,700 sq. ft. Cape Cod).

        February was our coldest month this winter with an average temperature of -1.8°C, the 11th being the day of greatest demand. Our estimated heat loss on that day was 129 kWh(e) and our two ductless mini-splits consumed a combined total of 52.6 kWh for a COP of 2.45. For the full month, their estimated COP was 2.9.

        Our mini-splits pretty much pack it in for the day when temperatures dip much below -15°C, and at that point our boiler gets pressed back into service (largely for comfort reasons, and to hopefully prevent the radiator lines from freezing where they're routed through exterior walls). Upon their retirement, we'll replace them with high efficiency cold-climate models that maintain 80 per cent of their nominal heating capacity at -30°C and that use, on average, one-third less energy.

        1. T_Barker | | #80

          What exactly do you mean when you say,
          "I estimate our home's average heat loss at 0.21 kW per °C whenever outside temperatures fall below 15°C"? And how did you come up with this magic number?

          1. CollieGuy | | #86

            As mentioned, I ran our oil-fired boiler over a two week period as our sole heat source, the indoor and outdoor temperatures and fuel-oil usage for one of those fourteen days shown below.

            During this twenty-four hour period, our Netatmo weather station recorded an average indoor and outdoor temperature of 20°C and -2.1°C respectively, and our MazoutMan fuel monitor pegged our oil use at 15.37 litres. At an AFUE of 84 per cent, we receive 9.0 kWh(e) of heat from each litre consumed, so that translates to be 138.33 kWh(e) delivered; divided over twenty-four hours, an average of 5.76 kW or 0.26 kW per °C.

            However, I notched that back to 0.21 kW/°C for three reasons: one, the boiler was also supplying our DHW via our SuperStor Ultra indirect water heater, so some of that energy can be rightfully attributed to that purpose. Secondly, indoor temperatures were a little more uniform throughout our home due to the better distribution afforded by baseboard heat, whereas some rooms are normally a bit cooler with our ductless mini-splits given that they're point sources. Lastly, the boiler exhausts previously conditioned air during its operation and continues to leak air when idle (on particularly windy days, the damper rattles-out a fiendish Morse code); to minimize the amount of air that escapes up the stack, I temporarily seal-off the vent whenever the boiler is not used. Thus, after subtracting the DHW portion of our usage and our home's somewhat higher heat loss due to more uniform indoor temperatures, and accounting for the additional air leakage related to the boiler's venting, I've estimated our average heat loss to be in the order of 0.21 kW per °C.

    2. Jon_R | | #9

      Instead of using inaccurate load estimates, I'd use your rated HSPF / 3.4 = COP = 2.74 as a best case. Then adjust the HSPF downward for your climate, meaning that COP = 2.5 is more likely for your old heat pumps. See somewhat related measurements from here where they reached 90% (not 128%) of nameplate HSPF/COP. Any supplemental resistance heat would lower system COP even more.

      1. CollieGuy | | #12

        I monitor their performance rather carefully, and consider my estimates to be reasonably accurate.

  2. Jon_R | | #2

    Agreed, it is more accurate to qualify "all electric is greener" with "over the service life", "in most areas" and/or "with heat pump use".

    To be a universally (vs typically) good thing, a national policy of "no more gas hookups" would need to combined with "electricity generation in all areas will soon be cleaned up". You should support both together, not oppose the former.

    > This case against natural gas simply isn’t true.
    In most cases (ie with heat pump use), it IS true.

  3. user-723121 | | #3

    The best read on GBA for 2021. Thank you for the detailed and understandable breakdown.

    1. bee_clark | | #28

      Agreed. This is a good topic. Like a good scientist, the author is right to be skeptical. Without a thorough analysis, it is wishful thinking that the electric grid is now or soon will be cleaner or greener in every region. Green building standards and best practices should follow the data.

    2. creativedestruction | | #29

      Agreed, a solid article that approaches the complex problem with healthy skepticism. I especially appreciate this perspective:
      "I am not an advocate of unfettered free markets, but neither do I believe that the world can be saved by good intentions that are not manifested in rational, data-driven policy."

      'Clean' or 'green' energy production is a misnomer. It's all dirty by some measure. I advocate that we design to use less energy regardless of the source. And more so than any alternative I believe full-electrification offers the opportunity for lower emissions, if not at the time of construction then over time as the grid can be improved on a macro scale.

  4. AndyKosick | | #4


    I have so many problems with this analysis that I'm not sure where to begin. I'll try to make to make a few important points.

    The first is that your thoughtful but admittedly armchair analysis is at odds with that of many others.

    The second is strategic and can be summed up by the phrase "there are no trophies for second place" The fact that this analysis is so focused on the now, is the problem with it. If we do not begin positioning society for zero emissions now, we have already failed. Every new gas furnace fired today is that much further to the finish line. The incremental emissions of electrictrifying homes now is inconsequential to the need for everything to be electric as soon as possible. Which will take a couple decades even at a breakneck pace.

    Yes, this means the grid has to be cleaned up, but that's just it, the grid MUST be cleaned up. We have to walk and chew gum at the same time. If both electrification and clean generation aren't happening at the same time we won't get there. Certainly not in time. There is more urgency here than you appear to realize. We need bold leaders in home electrification.

    The last point I'll make is economics. It's little bit of a chicken and egg thing, but the best way to think about cleaning up the grid fast is that people need to use more electricity. More demand means more generation to build and rate base to fund it, and that generation will most likely be renewable because it's now the cheapest option. Since so much investment is needed, the more people that are buying electricity, the less it will cost each person. I could go on.

    I hate to use a war analogy, but it speaks to the scale of the problem. You're trying to spare a few lives in taking the next hill, but at the expense of losing the war.

    1. JC72 | | #6

      This may help

    2. jameshowison | | #10

      This is my reaction as well.

      The question is how to we plot a path to emissions that keep climate change at manageable levels. You don't consider the path, just the current situation.

      That means ensuring that today's investment decisions make the path easier. Electrification does that, meaning that we can rapidly eliminate the dirtiest sources (e.g., coal and tar sands), temporarily substituting with centralized natural gas driven electricity generation, then permanently reducing the use of natural gas as we learn how to manage a zero-carbon grid.

      The more investments that homeowners, utilities, cities make in delivering gas to houses, the higher the cost of the transition that is unavoidable.

      Another way of thinking about this, perhaps, is that there is only a certain budget of natural gas that we can burn over the next 20-50 years (if we are to prevent the worst issues of climate change), and a great amount of that (perhaps all or more!) is already spoken for by the cost and time needed to transition current users of fossil gas. So, should we use what budget of natural gas remains for a combination of high-temp industrial uses, or centrally by generating electricity, or should we spend more money to use up the remaining gas budget quickly, stranding those infrastructure and homeowner investments even earlier?

      1. charlie_sullivan | | #32

        James and Andy have done a great job of explaining the most important conceptual error in the approach of this article. We need to get to a low emissions future. Electrification and expansion of renewable generation is a way to get there. Sticking with gas furnaces and stoves will prevent that future.

        If we didn't have heat pumps good enough, and we'd be clearly taking a step backwards by installing heat pumps now, we might want to hold off on that until the grid is better, but anywhere in the country an air source heat pump annual average will can beat the COP=2 threshold proposed by the author; in many places beat it by a large margin. As the grid gets cleaner, we'll then be positioned to reap the benefit of that, whereas a gas furnace won't get any better over time.

        And of course individuals who want to do better can install solar, sign up for a renewable energy provider, or purchase RECs if neither of the first two options is available.

        1. liznewman | | #46

          Thank you, Charlie -
          I think your last paragraph about solar is the key. Accelerating the expansion of solar and wind by whatever means needs to be the focus on every scale, from personal to global.
          Every fossil fuel installation is likely concretizing the use of additional fossil fuel in its location for the life of the equipment. If government subsidies and incentives for these replaced those for fossil fuels, renewables would evolve much faster.

        2. mrkawfey | | #121

          Completely agree. I hate to be rude (really, I don't like being rude online) but this article needs a blunt statement in response: The author has wasted his time in presenting this well researched and analyzed data by failing to see the forest through the trees. And worse, it has likely influenced people to adopt (or continue) this self-important, false equivalence narrative.

          This is not a complicated issue anymore. We are past the point of being able to look for climate solutions that are "optimized". 40 years ago this article would have been brilliant. Today the only choice is to eliminate all point-source emissions as fast as possible regardless of cost.

          As individuals, we can't concern ourselves with the marginal difference between pollution from electric generation vs heating with fossil fuels. Just take every opportunity to eliminate CO2 emissions from your life. It is a dumb argument to say "I'm going to keep using gas because the power company hasn't cleaned up their act yet." It's the same as the childish "I know you are, but what am I."

          You don't have direct control over what anyone else does. Do your part first. We are partly in this mess because no one wants to be the first one to make the changes.

      2. HFF | | #65

        Thank you for this reasoned response. I completely agree that we need to "plot a path to emissions that keep climate change at manageable levels".
        But let me pose this. Perhaps there is a limited budget of money and more importantly, political and societal willpower, to transition to renewables. Is the elimination of domestic natural gas the hill we're willing to die on? I think not.

        1. Expert Member
          Dana Dorsett | | #72

          >" Perhaps there is a limited budget of money and more importantly, political and societal willpower, to transition to renewables. Is the elimination of domestic natural gas the hill we're willing to die on? I think not."

          We're not going to die on that hill- gas is going to die of it's own heavy financial weight and sooner than you might think. It won't need to be pushed. Gas is only cheap in the US right now due to ubiquitous fracking for oil. With the ongoing electrification of transportation world oil demand is likely to peak before 2025 (and may have already), and as demand shrinks fracking has to get a LOT cheaper to stay competitive, and the price of the natural gas will have to rise to keep those operations in business.

          There's a good chance that as oil demand goes into structural decline the way coal demand has (yes, coal WILL be going away sooner than most people think) the price natural gas will rise as the natural gas byproduct of fracking for oil fades from the market. Gas is only cheap right now due to the fracking boom.

          Add that to the fact that as the gas-grids need major overhaul to reduce fugitive methane emissions the cost of those upgrades & repairs get passed on to retail ratepayers. By 2030 residential retail natural gas is going to be priced out of the market against heat pump solutions in much of the US.

          In my own high-priced electricity + high priced retail gas neighborhood the delivery costs are already about 60% of the ($1.70/therm) total bill, and even at our steep ~!26 cents/kwh electricity better class heat pumps are a operating cost parity with mid-efficiency gas.

          Over the past month my VERY local piece of the gas distribution grid (a 4 block area near my house) has been undergoing extensive gas main replacement as well as repairs to leaky service taps to homes. Applying the amount of money spent to simply decommissioning those mains and paying for all-electric conversion may have been a better expenditure of funds in the intermediate term.

          It's hard to see how retail natural gas can get significantly cheaper than it is right now. Even if the energy portion of the gas bill went to zero, the distribution cost isn't going away, whereas electricity pricing has downward pressure brought on by ever cheaper rewewables.

          Already even without tax credits & other incentives the levelized cost of rooftop solar in my neighborhood is about half the (higher than US) retail grid cost, and net metered to a heat pump the cost is already WAY below heating with condensing gas, provided you have the roof & capital to deal with it and the regulators continue to allow net metering. If electricity & gas prices continue to rise (likely, in my area) by 2030 it'll be cheaper to unplug from both the gas and electric grid.

          Energy markets writ large are already further in to the disruption from cheap renewables than most people (even many industry analysts) realize. Given the learning double-digit percentage learning curves of wind, solar and batteries, by 2030 electricity will be much cheaper than business as usual. The business models of utilities will simply have to adapt or they will fail.

          A decade ago these statements would have been seen as some crazy pie in the sky, and many people still think so. (Mmmm- PIE! Yum!) But the learning curves of these technologies are RELENTLESS, and take no quarter. The think-tank Rethink-X recently published an analysis of the grids in three US regions, Texas, California, and New England, and using real weather history determined that the going with just wind solar + battery technologies there were many solutions to 100% renewables possible by 2030. But not only that, the cost-optimal mix would be cheaper than business-as-usual. More here:

          Cutting to the chase, they concluded that even continuing to maintain & fuel the existing nuclear & fossil generation fleet would be more expensive than doubling or even quadrupling renewables output (renewables output of 2x-4x the total amount of energy currently delivered by the grid) would be cheaper in those three markets, and that pretty much all existing fossil generators are doomed to become stranded assets within the next decade, two at most.

          So yes, PLEASE electrify everything, and push back on protectionist efforts of utility & fossil fuel interests whose oxen are being gored. There is nothing to be gained by prolonging the pain of this transition.

    3. tommay | | #15

      "It's little bit of a chicken and egg thing"..or is it more like putting all your eggs in one basket? We live in a world of diversity...the real answer is use less, adjust and adapt. A sweater is much cheaper in the long run.

    4. Granular | | #48

      Reality is Chindia's (ever-increasing) massive use of coal makes whatever we do in the West superfluous. West could be carbon neutral and still CO2 levels will increase.

      Fun fact: China alone adds more generating capacity every year than the UK's entire grid. India is far below China's energy usage per capita and its population is growing much faster, so just wait, the world hasn't seen anything yet wrt to CO2 emissions...

  5. paul_wiedefeld | | #5

    Thanks for the article Fred. Your 2019 numbers show that .9 CO2 lbs/kwh combined with a heat pump annual COP of 2.5 has carbon emissions 10% under a 95% efficient furnace. A COP of 3 saves 32% of carbon emissions compared to natural gas, not even accounting for methane losses along the way. I imagine methane losses are worse within the residential distribution system, but I could be wrong. 2020 was an even rosier emissions picture, but with a pandemic caveat. Other emissions are worrisome, but take a lot at EIA's planned coal retirements. 60% of planned retirements by MW are coal steam plants (24% are less efficient natural gas plants).
    Replacing a centrally ducted furnace with a centrally ducted heat pump seems to be a one day project. The quotes I received for AC + gas furnace (low efficiency) weren't much cheaper compared to a cold-climate heat pump even though the installer was pushing the subpar (oversized, single speed, loud, large) AC + furnace option hard. At $1/therm and $.12/kwh, a standard efficiency furnace is at fuel cost parity with a 3 COP heat pump, and my gas is higher and electricity cheaper than those costs.
    Important to note is that many localities allow you to buy 100% clean energy today, sometimes for no additional cost. If sticking with the standard offer, a heat pump installed in 2021 will become cleaner as the grid improves over its lifetime, a furnace won't - even if natural gas is a majority of generation.
    In summary, if we accept that coal plants will continue to be replaced by a mix of renewables and natural gas combined cycle plants, then electricity will become no doubt cleaner and likely cheaper. For vanilla central furnaces replacements, an air-source heat pump will be at least competitive on an installation and fuel cost basis and significantly cleaner even if based on 2019 numbers. I think it's important for GBA readers to do their own calculations if so inclined, but if busy - err on the side of electrification.

    1. HFF | | #42

      Paul, I agree with your summary. I would be perfectly happy with a grid powered by natural gas with increasing renewables, even if subsidized, adding to the mix. However, it has been my understanding that "all electric" advocates accept no role for NG as a transition fuel. I think that is misguided and I don't accept the premise.

      1. paul_wiedefeld | | #63

        I agree that's misguided and unrealistic. I see gas continuing to eat into coal's generation share but then run into renewables soon enough.

  6. Expert Member
    ARMANDO COBO | | #7

    I have a very simple approach. I suspect that fossil fuel electric production is dwindling and a dead industry in the foreseeable future, sadly not in my lifetime. So what are the best alternatives for clean energy today? I see solar, hydro, wind and nuclear as the major players. Nitrogen, tidal, biofuels, biomass, solar thermal and other new technologies that could be players in the mix, if they can be applied to large economic scales.
    Who knows, maybe even space solar or energy collection maybe a thing of the future. None of those technologies are perfect, but some are better than others, and improvements in technologies will make them better and safer.
    For me, as a Residential Designer wanting to place my small pebble in the sand and our industry, solar PV and zero energy buildings is a great alternative and contribution. The future is won by those who seek change, innovation and new possibilities. Staying with old technologies or doing nothing is not an option.

  7. _Stephen_ | | #13

    "On the other hand, just about all the natural gas produced and delivered to the home is efficiently burned and utilized."

    This is false in terms of the broad generalizations you claim to dislike so much. A gas stovetop for example, is only about 40% efficient, vs an electric at around 75%, or an induction cooktop at around 85%. Most southern furnaces are only 80% efficient.

    You also ignore the often expensive 'grid connection fees' that must be paid just to have the pleasure of being connected to the natural gas grid. For my area, that is around $35 / month, before your first BTU is purchased. In efficient homes, this cost dominates the discussion entirely. Adding $400 to your annual heating bill in natural gas fees changes things when your total consumption is about the same size.

    I will echo other comments about looking at things over the service lifetime, as opposed to only present conditions. Will a furnace installed now still be lower carbon in 10-15 years? What about the cost of natural gas? Natural gas is currently enjoying a period of incredibly low costs, that are likely to disappear, as North America starts to actively export billions of cubic feet per day (projected to hit 30 BCFD in 2030). This will likely be enough to start turning around a decade long trend of declining prices, and start things going the other way. China will be happy to purchase massive quantities of natural gas from us. So, when natural gas is double the current cost(which was true 20 years ago), what happens then? Electricity prices are much more stable, and a safer bet.

    1. paul_wiedefeld | | #16

      Another good point - basically the stars are aligned for natural gas: lowest historical prices, still a transitioning grid, cold climate heat pumps are on the newer side (air to water is almost non-existent). Still, the best we can say is that a furnace might be few thousand $ cheaper to install, blows a slightly higher air temperature, can't provide air conditioning, is at least 10-20% more carbon emitting on average, comes with its own connection fee that ranges from small to steep, can sometimes be slightly cheaper on a heat basis, might use clean gas in a decade (or never?), usually don't poison you, and exposes you to one, variable fuel cost. If the situation was flipped and furnaces were the new technology, why would someone buy one?

      1. AndyKosick | | #18

        "If the situation was flipped and furnaces were the new technology, why would someone buy one?"

        I absolutely love this perspective! I'm stealing it for presentations. For a homeowner heat pumps are basically the better technology from every angle except cost currently. (They just don't realize it yet)

    2. JC72 | | #19

      "This is false in terms of the broad generalizations you claim to dislike so much. A gas stovetop for example, is only about 40% efficient, vs an electric at around 75%, or an induction cooktop at around 85%. Most southern furnaces are only 80% efficient."

      Are you measuring from the wellhead to the output of the appliance? (assuming electricity is generated via NatGas).

      Induction is nice but it's 3x-4x the cost of gas. I just installed a new gas range a couple of weeks ago.

      1. CollieGuy | | #23

        Ten years ago, not wishing to spend a whole lot of money, I picked up a couple commercial grade, 120-volt induction hobs, second hand; a Vollrath Mirage and Tarrison CI-18-1, the latter for just $60.00 CDN.

        1. JC72 | | #25

          Induction hot plates are cheap, but the majority of homeowners want a traditional range in their home. It's a home not a dormitory if you know what I mean.

          I really wanted an induction range but it was just too damn expensive

          1. CollieGuy | | #27

            Completely understand. We have a six burner Heartland Legacy propane range, and didn't want to chuck it out in our efforts to lessen our fossil fuel use and improve indoor air quality. It was an imperfect compromise, but one we decided we could live with.

        2. Expert Member
          MALCOLM TAYLOR | | #47


          The 1100 sf house I'm designing now has a two burner induction cooktop, and outlets on the Island for two more portable induction hobs. I think the flexibility can be an asset.

          1. CollieGuy | | #49

            I like the added flexibility that they offer, in that I can move them outside to minimize the amount of heat and humidity, and cooking odours generated when preparing a meal (boiling lobster comes to mind). I can also run them on generator power in the event of an extended power cut if I so choose.

            Induction is fast; offers more precise temperature control; energy-efficient; safe, i.e., no open flame nor risk of fat fires due to temperature regulation; and there are no harmful combustion by-products.

            Moreover, they're easy to keep clean. One of my biggest gripes with our propane range is that every time something spills over I have to pull apart and scrub a bunch of grates, burner rings and related hardware. With our induction hobs, a quick spray of window cleaner and a piece of paper towel is all that's needed ― nothing gets baked-on to the cooking surface as is often the case with natural gas and propane.

          2. Expert Member
            MALCOLM TAYLOR | | #50

            You had to mention boiled lobsters as I contemplate a breakfast of granola or toast.

      2. _Stephen_ | | #34

        I'm measuring from entering the home to use in the appliance, because I was objecting to the quote specifically that all natural gas is burned efficiently in the home.
        That is not true.

        1. HFF | | #43

          I would like to see a citation on your stovetop efficiency claims. Are you referring to the efficincy with which the burner transfers heat to the food?
          With regards furnace efficiency, you're comparing the crappiest gas-powered with a modern efficient heat pump. Not a fair comparison.
          Yes, I did not mention hookup and sevice fees.
          You are pointing out several reasons why I recommended that the individual consider their own circumstances and decide accordingly. You've done that and decided on electricity. Great!
          Finally you seem to be suggesting that outsourcing our NG emissions to China is inevitable. It seems odd to me that we will acknowledge this while preventing modest income Americans from selecting a fuel source that meets their needs.

          1. CollieGuy | | #45

            If it's helpful, I've copied the following table from Frontier Energy Report # 501318071-R0, "Residential Cooktop Performance and Energy Comparison Study".

            According to the manufacturer's cut-sheet, my Vollrath Mirage Pro is 90 per cent energy-efficient, and my Tarrison is reportedly 85 to 90 per cent efficient.

          2. HFF | | #51

            Thanks CollieGuy,
            I can understand why induction is a significantly better heat transfer mechanism than conduction. I'm curious about NG vs electric coil, though. In my entire life, I've never used an electric stove top that boils water faster than NG.

          3. _Stephen_ | | #52

            Firstly, I think CollieGuy has cited a source for the efficiency of natural gas stoves. A lot of the heat simply travels past the pot, instead of going into the food. You can easily feel this when you hold your hand around the ring. There is a column of hot rising air that travels past the outside of the pot. This does not happen with other burner styles.

            Secondly, I am not comparing 80% furnaces to modern mini-splits. I am pointing out that not all natural gas delivered to homes is burned efficiently, as was stated in the article. In fact, large volumes on natural gas delivered to homes is used for inefficient stoves, BBQs, and low efficiency furnaces that are incredibly common in huge swaths of the southers states.

            Finally, I am not suggesting that modest income Americans be prevented from selecting any fuel source. I am suggesting that the current environment that makes natural gas economically favorable will be coming to an end with the service lifetime of equipment purchased today, and that it is reasonable to expect natural gas prices to return to historical norms at roughly double the current prices. With natural gas prices doubled, minisplits are much less expensive to operate, in many regions of North America.

    3. irene3 | | #37

      Gosh, I thought our hookup fee was high at $11.50 a month. People go on and on about gas water heaters being cheaper to run, but if you're not splitting the gas hookup fee over several appliances, it ends up being quite a lot of the bill (our total is around $25 a month). I'm starting to wonder if we're even going to need to bother buying a heat pump water heater when we go electric, given that there are only two of us and our usage is pretty small, or if we could get by with a 40 gallon standard one.

      1. steve_smith | | #40

        Depending on your climate and water heater locations, the heat pump water heater can also provide some nice ancillary benefits. I am currently appreciating my cool garage when it is hot outside.

        1. irene3 | | #77

          We're in Seattle, so not much super hot weather. The water heater is in the unfinished basement, which stays fairly cool year round, so it doesn't much matter either way. I suppose if we replace our ancient dryer with a heat pump (hence unvented) one, that would put heat into the room, and a heat pump water heater might take it out again.

      2. _Stephen_ | | #41

        My hookup is $35. My monthly usage is $8. I am annoyed.

        Right now, I have a natural gas water heater, a natural gas stove, and a natural gas fireplace.

        The water heater and stove will be replaced at the end of their lives. The stove in particular we are disappointed with. The fireplace leaks air badly enough that it you can feel the cold air sliding along the floor on a very cold day. It's sealed combustion, but the air seal around the exhust must have failed.

        We also have a natural gas BBQ that we can get a kit to replace.

        1. this_page_left_blank | | #82

          The seal may have failed. However, it's entirely possible to have cold air coming from the fireplace with no leaks at all, simply from conduction from the outside to the inside through the pipe. Think of a single pane window, only even worse than that.

  8. charlie_sullivan | | #14

    Just one of the many errors in this article:

    "A not commonly known fact is that two thirds of the total electricity produced in the U.S. is “rejected”."

    That's a misunderstanding of that graph. What is rejected is not electricity, but heat.

    I welcome a critical discussion of the broader question but it would good if GBA editors could ensure a basic level of technical accuracy for articles published here.

    1. Jon_R | | #17

      Agreed, generically, GBA quality would be better if there was more use of an optional preview period with private responses providing the author a chance to edit before "publication". Could be as simple as email.

    2. HFF | | #22

      Did you read the next sentence?
      "A not commonly known fact is that two thirds of the total electricity produced in the U.S. is “rejected”. Rejected energy is that which is lost through waste heat; it includes the energy needed to generate electricity at the power plant, as well as transmission and distribution losses."
      What technical errors have you found?

      1. charlie_sullivan | | #24

        So was that a typo then, that the first sentence used the word electricity?

        1. HFF | | #26

          Ok, "two thirds of the energy used to generate electricity in the U.S. is rejected."

  9. SCChris | | #20

    If homes were tents (go up in a day, expected to stay up one week) this might make sense.

    Seems like there's missing all the points about wanting to survive as a species, etc

  10. Deleted | | #21


  11. Jbagnell | | #30

    In my home in Ontario, I'm planning to replace my gas water heater with an electric one. It will cost me more to heat water, but I can:
    -Put the water heater wherever I want
    -Easily install and repair it myself
    -Eliminate two holes in my house (the power vent exhaust and the fresh air intake)
    -Remove a potential source of carbon monoxide

    Plus our grid is relatively clean, if you don't count nuclear waste. One problem at a time...

  12. lukasmpeter | | #31

    Minor correction:
    per "Methane (CH4) is estimated to have a GWP of 28–36 over 100 years" not 25 as stated in the article.

    1. steve_smith | | #33

      Also of note is the GWP20 value of methane is 84-87. Methane breaks down into CO2 relatively quickly in the atmosphere, but until then it traps heat much more effectively than CO2.

  13. Expert Member
    MALCOLM TAYLOR | | #35

    This is an interesting and thought-provoking blog, which as provoked a very good discussion. Whether you agree with Fred's conclusions or not, I'm glad GBA publishes a diversity of opinions on these types of topics, and doesn't have a "house" position that has to be adhered to.

    1. T_Barker | | #107

      I agree. As soon as I read the article I thought "wow, good for GBA for allowing alternative opinions".

  14. BirchwoodBill | | #36

    From a pragmatic perspective, I designing my retirement home for "all-electric". Being a libertarian, the house is also providing "freedom-of-choice" for supporting Natural Gas cooktop, Dryer, and Porch Fireplace. There was a NG boiler in the design, but for new build with 0.6 ACH the BTU per hour is only 15,000 demand on design day. If you look at the average low temperature, the heat loss is 8000 BTU per hour. A NG gas boiler can only modulate down to 8,000 BTU per hour - so why heat with gas in a Pretty Good House when a Heat-Pump can do the job and simplify the components (and reduce 2 penetrations). Will spend the money on solar panels.

    For the future, I see Natural Gas generators becoming "Hydrogen" powered generators. Then we will be stuck the H20 emissions standards rather than CO2 standards.

  15. irene3 | | #38

    Another factor is safety, especially around children and while aging in place. Induction stoves are the safest way to cook, as there's no open flame and the stove top doesn't get nearly as hot. And while it's admittedly a rare occurrence, I live just a few miles from where a gas explosion took out a whole batch of businesses a few years ago.

    Also consider this: "What if grids need new gas plants for only half of their lives? The economics do seem to be changing. In Texas, a gas plant built in this decade went bankrupt in 2017, in part because it struggled to compete with the state’s cheapest power sources: renewables."

  16. maine_tyler | | #39

    I second Malcom's point in #35 regarding the discussion.
    I also second James' (#10) post and other similar notions in regards to how I would conceptualize this in a broad sense.

    I have to admit to being confused by some of the analysis. For example:
    >"Let’s compare total output emissions with those attributable to natural gas alone."
    Why? Is this being used as proxy for emissions from natural gas furnaces and household appliances? I feel I'm missing some of the reasoning behind most of that entire block of analysis there.

    >"For the Eastern Interconnection, I’ve pooled the outputs of 4 NERC regions"
    If the point of this piece is that we ought to do more thorough analysis and make less blanketed statements (which I agree with) I'm not sure doing analysis at this resolution is that telling for any given individual. Yes the grid is 'connected' but that doesn't really mean the actual power you see at your house is homogenous to these very large regions. In other words, some places will look better for electric, while some will look better for gas. I appreciate the caveat that it was for simplicity and brevity though.

    >"These amounts seem to violate the law of mass balance. If every carbon atom of natural gas were converted to CO2, the total would be 400 lb./MWh."
    Where did this number come from? Carbon atoms to CO2? What's that got to do with rejected energy? [edit: nevermind, I misread that sentence in regards to carbon atoms... still don't know precisely where 400 came from, but I can see how it should probably be pretty close to that] I'm pretty confused by this bit, though I understand the general point about rejected energy.

    Speaking of which, note that the losses are highest amongst old burner plants, and will only improve—even if the grid conversion was just from coal, oil, and old gas plants to modern natural gas combined cycle.

    I think this piece makes a really strong argument in favor of not letting coal lobbyists control the markets, policies, or anything in Washington.

    It's summary of points at the end isn't that disagreeable to me, but it's also not news to me that electrification won't win in the analysis across the board at this point in time.

    Lastly, I'm a Mainer where we burn oil or wood (largely, geographically speaking). So in choosing a new system, electric is not often weighed against NG at all, but oil.

  17. Expert Member
    ARMANDO COBO | | #44

    Just in case anyone wonders who the major polluters are... (3 years old, but relevant)

    1. Jon_R | | #59

      Looks like they are attributing the pollution caused by end users burning a fuel to the company that removed it from the ground. Imagine if we acted on such logic with XPS - "I didn't produce it (or I wasn't the first buyer), so it's harmless for me to buy and use it". Producers, consumers, government that allows free atmospheric dumping - all are guilty.

  18. [email protected] | | #53

    As others have pointed out, GBA sometimes publishes articles in which an author's reach exceeds their grasp. For example, the blogs by would-be hipsters with little construction experience who want to share all the details of their "build" adventure. As a builder I find these annoying and unhelpful.

    This piece has a similar problem-- a non-specialist trying to take on an important extremely complex issue, and making a big mess of it.

    There are a lot if problems with this article. The most obvious one is that it mostly ignores the single biggest reason natural gas is a threat to the environment. The GWP of methane is very high, and highest in the near term when it matters most. This, combined with the fact that gas leaks systemically throughout the infrastructure of extraction, distribution and consumption, makes gas worse for the climate than coal or oil. This issue has been widely studied by a lot of very smart people and, fossil fuel funded science and propaganda notwithstanding, there is well-founded consensus around the idea that we need to stop using gas because, although it burns cleanly, it's actually the dirtiest energy there is.

    I'd like to politely suggest that GBA reexamine its editorial standards. Publishing this kind of content in the name of green building is maybe a bit like selling bubble wrap for insulation don't you think?

    1. krom | | #54

      An awful lot of natural gas, goes into the atmosphere all on its own every day, has for millions of years, and will continue to for millions of years.

      1. maine_tyler | | #57

        Keeping everyone in check with your rigorous logic, eh Trevor.

        Depending on which source you look at, humans are responsible for an estimated 60% of methane emissions, (this particular number I pulled off Wiki. I welcome other cited figures). We're also responsible for pretty much 100% of incremental 'new' emissions, which is kind of the rub. Since the industrial revolution, atmospheric methane concentrations has more than doubled.

        The earth used to be different in all kinds of ways, including—as you point out below—having higher atmospheric CO2 concentrations and being much warmer. It also used to have dinosaurs, be covered in ice (on again, off again), and at one time even didn't have any life! Just because something used to be doesn't mean we should strive to go back to it (referring to the higher atmospheric greenhouse gas concentrations).

        Climate change science has degrees of uncertainty—that's inherent with such a discipline—but I think we can act on the certainty that is there without creating a hell on earth. My opinion is that this 'hell' some people fear will be created by combating climate change (i.e. "annihilating the economy, freedoms, and choices") is borne mostly by political virtue signaling. There's good and sound reason to believe this transition could be a boost to the economy, quality of life, and give more freedoms in many ways. But if one is married to the past, then yes it's frightening.

        Oh but China. Nevermind, you're right, let's party like it 1999.

    2. Jon_R | | #60

      > "well-founded consensus ... gas ... the dirtiest energy there is.

      IMO, it's a well founded consensus that coal is worse for the environment than nat gas. Even with leakage. Some of this is due to non Co2e pollutants.

    3. HFF | | #61

      Look, I can handle ad hominem attacks but I cannot allow your absurd and dangerous assertion that natural gas is "worse for the climate than coal or oil" to go unchallenged.

      I've found what I believe to be the highest estimate of methane emissions from combined NG and oil production and distribution. It is 13 Tg/y ( I don't know how much of this is attributable to NG, so let's assume 100%. Based on annual NG extraction of 32.1 Quads, this comes to 3 lb methane per MWh of energy. Someone pointed out in a previous comment that I used an incorrect global warming potential of 25, whereas the EPA-endorsed level is 27-36. Let's go with 36. That leads to 110 lb CO2 equivalents per MWh of energy. Someone else said I should use the global warming potential over the first 20 years, which the EPA says is 85. This leads to 255 lb/MWh. If we add this to the CO2 production from methane consumption (391 lb/MWh; in the article I rounded up to 400) we're looking at a total of 655 lb CO2 equivalents per MWh. So, assuming these worst-case scenarios, burning NG produces less CO2 equivalents than the average of 844 lb CO2/MWh from total US electricity production.

      Meanwhile, we're looking at 2,163 lb CO2/MWh if we burn coal, and 1,574 lb/MWh if we burn oil (

      I recognize that you are not advocating a return to coal and oil, but your conclusion is not only wrong but potentially incredibly dangerous. Unfortunately, the fossil fuel industry is not the only one with an agenda.

      Please point out other problems you have found in my article.

      1. HFF | | #62

        I meant for this to be a reply to comment #53.

      2. Jon_R | | #64

        > 655.. NG ... 844 lb CO2/MWh ... electricity

        Metrics mislead and IMO, most GBA related applications will use a heat pump most of time and so the more relevant metric is "CO2/MWh as utilized in the average home" (ie, accounting for COP). This cuts the 844 down to something below 422. With that, electricity is greener than nat gas!

        Nobody I know is promoting a switch to "all resistance electric".

        1. HFF | | #66

          If the benefits of eliminating natural gas are to extend beyond "most GBA related applications", then we all have to agree to subsidize the costs and installation of heat pumps, high-efficiency hot water heaters, and induction ranges in all the homes of America that currently use natural gas.

          1. Jon_R | | #67

            I'd prefer "charge for the externalities". Otherwise you get inefficient things like subsidies for a new induction range for someone who always eats out.

            Not making financial motivations and environmental motivations consistent is a serious strategic mistake.

        2. HFF | | #68

          In principle I strongly support taxes on externalities. However, I need to see a path where the burdens of such charges will not fall on those who can least afford them.

          Also curious about what you mean by "metrics mislead". I try to present factual data. I interpret them one way, but I certainly recognize the possibility of alternatives. Of course there are uncertainties, but I hope we can agree that this is the proper way to proceed. Having said this, I do apologize to all GBA readers for my initial underestimation of the methane emissions from NG. I've countered here with a worst-case scenario, which most likely leads to an overestimate. This estimate by the way includes all phases of production, flaring, storage and distribution to the meter. Still working on finding data on the contribution of NG to the total.

          1. paul_wiedefeld | | #69

            Fred, I think the article was well-written, I appreciate you taking the time to contribute.
            The status quo's negative externalities have long fallen mostly heavily on those who can least afford them and climate change is no different. In terms of health, financial, and climate impacts, subsidizing heat pumps seems to have a high ROI since the incremental cost is low. In a world were coal is phased out quickly in favor of cheaper gas and renewables, I'm unsure where the dispute is. We can still use gas to heat homes and water, the combustion will just be relocated.

          2. Jon_R | | #70

            > charges will not fall on those who can least afford them

            Let them fall wherever it is most efficient. If this contributes to an unjust wealth disparity problem, there are alternative ways to fix this.

            Given the generally consistent push to use heat pumps, it should be clear why "CO2/MWh utilized in the average home" (ie, COP adjusted) is more likely to lead a non-expert GBA reader to the right conclusion than comparing "CO2/MWh delivered to the entrance". Your metric may be factual, but why not use one less likely to cause someone to come to the wrong conclusion?

            > "I recognize that these numbers are not cut and dry. For example, if you use an air-source heat pump..."

            IMO, less biased would be "I recognize that these numbers are usually misleading. For example, you will probably use a heat pump..."

          3. HFF | | #76


            "If this contributes to an unjust wealth disparity problem, there are alternative ways to fix this." Are you really suggesting that the US is willing to address wealth disparity? More likely, as always, the poor will get poorer.

            "IMO, less biased would be "I recognize that these numbers are usually misleading. For example, you will probably use an air-source heat pump..."?"
            Funny, I think it would be more biased if I had said that most people would use a heat pump.

      3. AndyKosick | | #74

        ....and 0 lb CO2/MWh for PV.

        I'm sure I sound over the top to you, but just to be clear, some of us feel it is your conclusion that "is not only wrong but potentially incredibly dangerous."

        I accept NG as a transition fuel in as much as anything existing can continue being used as needed, but that anything new should no longer be built or installed. It might have made sense 30 years ago, but all signs point to the need to leapfrog to renewables. When JFK said we'd be to the moon in a decade, we didn't even know how to do it yet. We've already got 90% of the solution to carbon emissions, we just need to deploy it. At a society level the return on investment from avoided adaption is likely to be huge. I want the freedom to not have to relocated everyone from the coast lines.

        Replace coal with renewables, not NG. Replacement furnaces with heat pumps at end of life.

        Also, I'm really glad that GBA published your article, we need to work through this stuff. I only hope my arguments are somewhat persuasive. I don't want to be remembered as the generation that sat on our hands while the Arctic melted.

        We can find the political will if you'll join us Fred.

        1. Expert Member
          Dana Dorsett | | #78

          >"Replace coal with renewables, not NG. Replacement furnaces with heat pumps at end of life."

          Replacement at end of life usually makes financial sense but not always. Financially viable life can be influenced by policy incentives such as carbon taxes, equipment subsidies, and volatility in the energy markets. If my boiler failed this week I'd probably buy a cheap gas mod-con. But depending on policy decisions & energy markets do in the next few years I might retire the gas-burners in the house before end of life.

          Gas can't be much cheaper than it is right now, and that's without carbon tax, and with plenty of subsidy to the gas producers. There is strong downward pressure on electricity pricing coming from zero marginal cost /low levelized cost wind & solar, technology that just keeps getting cheaper year by year (as do batteries.) In my neighborhood even ignoring the subsidies the levelized cost of small scale solar is about half grid-retail already, and trending downward. Construction of offshore wind in New England that is just getting started is going to hammer away hard at the capacity factors of the combined cycle gas burners- since they can't compete with near-zero marginal cost electricity, so the retail grid power may come down a bit too.

          1. AndyKosick | | #88

            Where I'm at replacement with heat pump doesn't make financial sense right now, but it makes comfort sense. Honestly, NG is so cheap here right now it doesn't make me want to use it, it makes me nervous.

            I've probably tried to be too inspirational with my arguments. Fact is that variable speed heat pumps are just the best tool for the job most of the time. Comfort is worth paying for, isn't it kind of the whole point.

            Here in mid-Michigan (99% = 3F) many of the mid sized existing homes in my community have heat loads under 36k. I'm not kidding, this is based on measurement. Which means most of the year the lowest stage of the smallest gas furnace available is nearly 2x too big.

            I literally just dealt with 1600sf house 1960's vintage, modest energy improvements, and the owner had the furnace and AC replaced. Spent the long dollar on a modulating gas, 60k of course because that's the smallest you can get. Still had comfort problems. Turns out the ManJ is 28k, lowest furnace output is 29k. They've got a expensive single speed furnace. Measured loads based on usage put the house closer to 20k in reality. To match the load in this house a heat pump would have been the answer. This is the case in more existing homes than most people realize.

            If HVAC contractors really want to sell comfort, they'll end up selling heat pumps. That's got nothing to do with emissions, people are tying themselves in knots right now trying to defend obsolete technologies.

          2. Jon_R | | #90

            > comfort ... lowest furnace output is 29k

            The CC15-M-V goes down to ~6k. Even so, use a heat pump - it's greener.

        2. AndyKosick | | #91

          to Jon R Comment #90

          True, but I'm referring to what is available and serviced locally. The nearest Dettson dealer is in Kalamazoo (2.5 hrs away) and I work with him on Kzoo Habitat projects. One of the best HVAC guys in the state in my opinion. Anyway, he won't come this far and I don't blame him.

          If it's of interest, he's been using the C15-M-V because the compact is too hard to service. Further more, Kzoo Habitat's next couple builds are going to be all electric, with Fujitsu AOU18RLFC one to one ducted. We'll see if it sticks.

          1. Expert Member
            Dana Dorsett | | #110

            >" Further more, Kzoo Habitat's next couple builds are going to be all electric, with Fujitsu AOU18RLFC one to one ducted. We'll see if it sticks."

            A potential fly in the ointment with that model in that location is the lack of pan heater & controls for managing/mitigating defrost ice build up. The Carrier/Midea 1.5 tonner would probably be a better choice, despite the slightly lower HSPF efficiency and slightly higher minimum output @ 47F and slightly lower max output @ +5F:



            Like Fujitsu, Midea ducted minisplits can also be mounted in an upflow orientation.

            I just wish more my local Carrier installers had better familiarity with and support of their mini-split lineup, just as I wish more of the local Fujitsu installers would deal with ducts. I'm consulting on a project right now where a 1.5 ton ducted mini-split would be a slam-dunk solution. It's limited remodel of a 1930 vintage 800' single story house over an 800' full basement suitable for running ducts. Even before insulating the basement to current code min or adding more insulation in the 2x4-joisted attic it's coming in under 19KBTU/hr @ +10F (the local 99% temperature bin). With the planned air sealing & (modest) upgrades to the insulation it will come in with loads under 15K for both heating & cooling. It's currently heated by the original cast iron boiler, a couple of cast-iron rads from the original system serving the kitchen & bath and a total of ~25' of crummy 7" tall fin tube baseboard in the other rooms installed in the 1960s when they last re-worked the floor plan.

            In the new improved floor plan for the remodel there is a desire to move the wall that currently has the big recessed radiator and get rid of the chimney, as well as getting rid of the fin tube baseboard. Radiant floor using a hydronic output heat pump + ducted AC was considered, but the only locally available option would be LG Multi-Vs + Hydro kit which is both cost-prohibitive (and ludicrously oversized at 4 tons). They are close to being convinced to go the ducted mini-split route along with a heat pump water heater for the domestic hot water. With a small amount flex duct mechanically decoupling the vibration a 1.5 ton ducted mini-split would meet their low-noise requirements. We'll see...

      4. [email protected] | | #92

        Fred, please read this and consider retracting your article:

        Most US gas comes from hydraulically fracked shale and tight gas. Industry has spent millions on marketing "natural" gas a clean burning bridge fuel and corrupting science and politics in order to minimize downsides. The issues are technically complex and good information is hard to come by. The authors of the paper above have excellent credentials and are well-regarded within their discipline and their conclusions have withstood industry challenge.

        As you will see, the authors use a CO2 equivalence factor of 105 in the 20 year time horizon. In their analysis they use a leakage range of 3.6-7.9% of well production.

        In Figure 1 of the report you will note that even under the low estimate, shale gas is worse for the climate than coal or oil. The high estimate is truly dreadful. Conventional gas is only slightly better under best case assumptions. But given that fracked gas makes up most us gas production and given that industry skew on leakage data is extremely aggressive, it's fair and reasonable to conclude that "gas is worse than oil and coal ."

        By the way, there is no ad hominem here. I did not call you a fool. I said this article is not competent. If you doubt that and are open to peer review, you could send it to Bob Howarth or Tony Ingraffea or Renee Santoro for comment.

        1. Jon_R | | #93

          Once again, metrics mislead. That outdated paper uses "expressed per
          quantity of energy available during combustion". Which doesn't account for coal being very inefficient (37%) at producing electricity . And then there are all the other dangerous pollutants from burning coal. Coal is worse for the environment than nat gas. But this doesn't change "move directly from coal to non-fossil energy".

        2. HFF | | #95


          The numbers cited in this study were from the mid 90's, and even then represented an outlier estimate.

          Today, the EPA estimates 1.8% leakage, while the Environmental Defense Fund (EDF) says 2.3%. This is for the entire oil and gas sector. Importantly, a substantial amount of this comes from the Permian and Bakken fields. These regions are primarily oil producing sources. When you're in the business of drilling for oil, NG becomes a nuisance that has historically been vented or flared. Moving forward, there is strong regulatory and industry-led pressure to substantially reduce this leakage. The technology exists today, and the EDF reports that reductions of 80% are feasible. Note that the EDF is not some industry mouthpiece.

          More modern NG drilling operations such as in the Mercellus shale deposits have substantially lower waste. When you're in the business of selling methane, you are naturally predisposed to minimize leakage.

          In summary, the oil and gas sector is highly motivated to reduce methane emissions.

          1. [email protected] | | #103

            Well Fred, I know of three guys with Phds, decades of experience, and numerous publications to their credit who would be willing to dismantle this amateur fantasy. Especially that last part about the gas industry being motivated to reduce emissions. It's common knowledge that industry has fought tooth and nail against that for years-- in court, in academia, and at EPA. And now that energy prices are low and margins are tighter than ever, you think they they are motivated to spend money cleaning up their act?

            I could go on but it's like Tolstoy said:

            "The most difficult subjects can be explained to the most slow-witted man if he has not formed any idea of them already; but the simplest thing cannot be made clear to the most intelligent man if he is firmly persuaded that he knows already, without a shadow of doubt, what is laid before him.”

          2. [email protected] | | #104

            You can separate fantasy from fact if you spend 10 minutes on google and ignore the industry propaganda. For example you will find that EDF actually does have a history as an industry mouthpiece:


            And you will find that in 2020 scientist discovered the opposite of what Fred says:
            "Oil and gas methane emissions in US are at least 15% higher than we thought. An unprecedented analysis from Pennsylvania uncovers flaws in national data"


            I'm all for multiple perspectives and critical inquiry. But I worry that GBA risks undermining its brand, diminishing its credibility, and fracturing the community of readers if it uncritically publishes industry propaganda that fails to meet basic journalistic standards.

    4. SierraWayfarer | | #71

      Absolutely. This article is not well reasoned.

      Fred, what did you get your doctorate in, and what is your building experience?

      1. HFF | | #75

        I received my Ph.D. in bioengineering from the University of Pennsylvania. I have no building experience.
        In what way is the article not well-reasoned?

        1. SierraWayfarer | | #83


          You said, "On the other hand, just about all the natural gas produced and delivered to the home is efficiently burned and utilized.". I have a problem with this statement for a number of reasons.

          1) Burning natural gas in homes for heating requires a separate home system for cooling. Two systems rather than one with a heat-pump only.

          2) Burning natural gas in the home for heating requires a completely separate national below ground distribution system. Two systems rather than one.

          3) Burning natural gas in the home results in increasing burn-inefficiencies as heating appliances age. Much more so than with heat-pumps only.

          It is better to burn natural gas at electric utilities where efficiencies and pollution can be better controlled and so that natural gas distribution costs are minimized.

          In general, two systems are less efficient than one system.

          1. Deleted | | #96


          2. HFF | | #97

            Your first two points seem irrelevant to me with regards to the statement you have problems with.
            Concerning your third, modern gas furnaces have efficiencies in excess of 95%.

  19. krom | | #55

    I have to laugh at the sky is falling crowd on here. Even if you are positive that humans releasing CO2 that used to be in the atmosphere, back into the atmosphere, will destroy the earth....
    How do you ignore the fact that emissions from North America, aren't even a drop in the bucket. Folks are talking about annihilating the economy, freedoms, and choices, for a tiny incremental reduction, which has been and will continue to be vastly outpaced by the increase from china, then india, then packastan, then.....

    Its virtue signaling

    1. exeric | | #56

      Trevor, I think a person without a conscience about some things would tend to think that everyone else around them is virtue signaling when those other people feel something about the sorry state we humans are making of things on the planet. It's always easiest to say "well the other guy is worse than me so it's all good." That doesn't solve anything. It's like the ten year old kid in grade school when he gets caught doing something he shouldn't whining "Freddy did the same thing as me. Why am I getting punished?".

      1. krom | | #81

        Pointing out the fact that there are lots of developing nations who pollute far more than the US, and those emissions are cheap, and easy to reduce must have gone over your head..
        The fact is that in the EU and north america any reductions come at an enormous expense, since the low hanging fruit has been picked.
        The biggest impact on global emissions isn't ever going to come from the US, no matter how much $$ is spent, and what sacrifices are made.

        1. paul_wiedefeld | | #94

          There's one country with higher emissions than the United States and it has 4x the population. Per capita, the United States is the most polluting country of size. Emission reductions should start here, it's still cheap (often free) to reduce and we have left a substantial historical carbon footprint.

    2. this_page_left_blank | | #58

      "Folks are talking about annihilating the economy"

      Citation needed for this claim, please.

  20. SierraWayfarer | | #73


    I can give you a reading list if you are interested. We are in the sixth great extinction and we caused it. We owe future generations more than that.

  21. BirchwoodBill | | #79

    Natural Gas is a very efficient way to move energy, especially through a pipeline. It should be part of a well balanced energy portfolio, along with coal, solar, ocean waves, hydro electric and wind power. Fred’s discussion is not about the green religion, or green politics. NG has its place for now.

    I agree we need to stop subsidizing all companies and individuals and let market forces work.

    So stop complaining about paying the local gas utility for recovering costs, I.e. connection charges. They are maintaining critical infrastructure and keeping people safe. .

  22. Robert Opaluch | | #84

    1. GBA is a "big tent" that includes somewhat diverse perspectives. However I cringe when I read articles like this, or suggestions to use traditional site-applied closed-cell spray foam. GBA does need to established some limits of what we call "green building". Natural gas supply to single family homes doesn’t make the cut. (I realize the author was talking about the grid but comments extend to single family homes. As will the thoughts of readers of this article.)

    2. Note that many people will read this article and never plow through the comments, especially when there are so many. Some readers may conclude "Even Green Building Advisor says natural gas heating is a good alternative, so I'll go with gas, that cuz its cheaper than electric..." Maybe there should be an option for the author to update the article after reviewing critical comments. Or someone at GBA re-write a summary similar to Scott Gibson’s Q&A Spotlight summary articles.

    3. Finally, there’s one perspective that I believe almost all of us agree with, that hasn’t been explicitly mentioned much in the comments. If you want to reduce carbon emissions, the key is to construct more energy-efficient, sustainable buildings. You won’t need much energy to heat a PHIUS/Passive House, well-engineered passive solar or solar tempered building, or Pretty Good house. That’s where the incentives, building permit process, subdivision requirements, etc need to focus. And when you do that, it becomes obvious that fossil-fuel central heating solutions are not cost-effective and not needed, except possibly in places like Alaska and North Dakota.

  23. Robert Opaluch | | #85

    Can't vouch for the perspective here, but another way to think about it is by corporation rather than by type of power source:

    1. Expert Member
      ARMANDO COBO | | #87

      LOL - "Note that many people will read this article and never plow through the comments, especially when there are so many." Read my #44 comment.

      1. Robert Opaluch | | #89

        Hahaha, nothing like proving my own point! :-)

  24. SierraWayfarer | | #98

    You said, "Your first two points seem irrelevant to me with regards to the statement you have problems with.
    Concerning your third, modern gas furnaces have efficiencies in excess of 95%."
    I find you response real strange but then I know a guy with a doctorate in environmental science, who was paid by Exxon for 4 years to speak against 'global warming science' at churches.

    1. HFF | | #99

      Dear lord.

      1. SierraWayfarer | | #101

        I guess that says it all...

  25. Expert Member
    MALCOLM TAYLOR | | #100

    I'd like to commend Fred for his continuing engagement in this comment section. Rather than calling for him to retract his blog, I still think this exchange offers a valuable exchange on an important subject.

    It's well beyond the scope of my knowledge to comment intelligently on the topic, but is seems a lot less fanciful that the claims in many of the other blogs which haven't occasioned this level of criticism, and I see posters whose opinions I respect taking opposing views in this debate.

    1. SierraWayfarer | | #102

      Yes Malcolm,

      Like our nation and our great argument over its path.

  26. maine_tyler | | #105

    I believe part of why this piece has garnered such strong reactions is because it comes across as a 'pushback' piece: an attempt to argue against what is perceived as the predominant viewpoint here on GBA (and increasingly among many environmentalist circles).

    If the intent of the piece were narrowed or made clearer, I suspect it would be a bit less likely to see some of the harsh rebuke it has. Is it saying 'don't ban gas'? Is it more largely saying 'gas is still more desirable than electricity most/some/part of the time'? The bullet-point of opinions at the end, if intended as the main takeaways, don't really match the argument, language, and tone of the preceding piece, IMO.

    At least in part, it seems to be an argument against a strawman, against a point few are actually making (that right now, and in all situations, running a building on all electricity produces lower CO2 emissions than using piped natural gas).

    The analysis itself, while perhaps reasonably sound, is rather course-grained and rudimentary to the questions here. What does it prove, and what is trying to be proved? Do those two align? As a reader, I begin to wonder the connection between the analysis and the underlying thesis if there is one.

    One example of how language and structuring contribute to this ambivalence was pointed out by Jon:
    "I recognize that these numbers are not cut and dry," [to make mention that the entire analysis get's flipped upside when heat pumps are considered]. It sits, nested, below the much bolder headline: "So which is really greener?" where the immediately following paragraph states, "Now it appears that even the carbon balance of residential natural gas is “greener” than grid electricity from the Western Interconnection, even with 39% of the energy coming from renewables."

    That does indeed feel slightly disingenuous to me; a sort of 'what-about.' i.e. 'what-about electric resistance'. Well, is that what is being suggested? If so, then yes, an argument has been made against that.

    I don't think these thesis-less pieces are in any way unique, and in fact are quite common. I too commend Fred for his rather even temperament at engaging and I doubt there is any ill intention, nor was the fundamental analysis completely preposterous.

    But I do think the piece may be a 'pushback centric' rather than an 'analysis centric' one. It argues too broadly against a scattershot of thought, and it does not do so successfully against all cases. Regardless, I appreciate what it does offer and especially the discussion it has provoked.

  27. Jon_R | | #106

    Would be interesting to see an analysis of "Am I greener (than a heat pump) if I use natural gas and contribute $X to a carbon reduction cause"? This is important when considering early furnace/boiler replacement or when heat pump quotes are much more expensive than a nat gas option.

    Are we talking about 2 ton Co2e/year difference = $100/year?

  28. GBA Editor
    Kiley Jacques | | #108

    I knew when Fred sent this unsolicited piece that I would be opening a fat can of worms if I chose to publish it. I anticipated this backlash, although I had hoped for a friendlier, more debate-like tone; insults don’t do anyone any favors, and I commend Fred for his maturity when responding. I think he has introduced some infrequently discussed considerations around this often idealistic conversation, and he has sparked an important conversation. I appreciate his deep dive and data-driven approach. As Malcolm mentioned, GBA doesn't have an unyielding house stance; we advocate for "green" building and our content reflects that mission. We also want to share diverse perspectives, so when an article that bucks the trend in our collective thinking comes across my desk, I just might share it. I believe it is valuable.

  29. Expert Member
    ARMANDO COBO | | #109

    I've been so tempted to respond in kind to folks that can't allow others to have a different opinion with out getting nasty, I guess that is par for the course on the times we live nowadays.
    I also notice that most of the EXPERT participants, either are pseudonymous or don't have a description of who they are in their profile. It's easy to hide under a keyboard when the community can't find who you are, or know your qualifications. I guess they are called Trolls, and they come and go on the GBA.
    There's nothing wrong with Fred's article, nor the GBA publishing it. We all learn from diversity of opinions.... Mean people suck!

    1. SierraWayfarer | | #111

      Hi Armando,

      You and I will disagree on Fred's article, and that's ok. But, even as he had the right to post his views others had the right to respond. Fair is fair. I don't think I noticed any overt trolling though I admit I wondered about Fred after his response to a comment of mine and I would sure like to have that argument with him, face to face.

      I did find where to put my bio. Providing names and locations, I am not so sure that is a good idea. I spend money (vpn) and effort (constantly clearing storage) to keep from being tracked and I noticed that 94% of IPhone users chose to not be tracked at the last update. What purpose does a person's name and location provide in this forum? You will get to know a person by their arguments in the long run.

      SierraWayfarer is a better descriptor of who I am and as Shakespeare said, "A Rose by any other name would smell as Sweet" least I think it was Shakespeare

  30. maine_tyler | | #112

    I hear what you're saying Kiley, and agree there isn't the need for hostility. This is a complex and sweeping subject to be presented here though. Some appear to be asking whether this deserved the elevation of publication, since it is an opinion piece on a very complex and large subject. That seems a not-unreasonable question to me. There are experts on these matters (even they disagree), and it's hard to see Fred being qualified as one of them. He makes some pretty bold statements that would seem outside his purview and that much of his argument hinges on, such as 'Coal is not going away anytime soon.' As one example.

    Fred's undeniably right that on occasion an overly broad, simplistic, and untrue statement about electrification is made. It's great to challenge those, but should those challenges be elevated from a specific rebuttal in a comments section to a piece such as this? There is a gulf between the weight of a comment from some rando in the comments (like me) and one that get's 'published.'

    The fear for me is when narrative and opinion is dressed such that it is easily mistaken for something else—mistaken for an expert's unbiased and tested analysis for example. Fred's piece appears hearty and I could see it being easily misconstrued.

    GBA went to the trouble to dub members as 'expert' to help us tune our filters and know who has the necessary experience for trust in advice (I assume). Other statements need to stand on their own merits. It strikes me that publishing a piece like this elevates that opinion quite a bit and it is a place that needs to be earned. I could be way wrong.

    Perhaps we simply need built in disclaimer filters on all items of consumption today. Perhaps the best way to check our collective selves is simply via the intervening discussions (though not sure about that). After all, there are few places, if any, one can go to be delivered a perfect expert analysis straight to the noggin. It's always filtered through at least our own dumb heads.

  31. arossti | | #113

    It's not black or white, gas or electricity, there are systems to make the transition: - why does nobody talk about hybrid furnaces as a first step to 100% ASHP?? Whenever gas furnaces are replaced, they should ALWAYS be hybrid and ASHP-capable. This supports deeper retrofit measures over time in the case of early equipment failure.

    1. paul_wiedefeld | | #114

      I like this approach - the perfect need not be the enemy of the very good. However, the prices seem off in the link - a drop-in heat pump replacement of a furnace (especially the lower end stuff) is comparable and energy cost might decrease. I like the idea of always recommending a hybrid approach and never thinking twice, but with a little prep it's easy to just choose the heat pump. An easy way to prepare for this is nailing the heat loss before the furnace breaks. A lot harder to get upsold into a hybrid system if your heat loss is 30k btu instead of 60k.

      1. arossti | | #115

        Numbers are Canadian dollars if that matters.

        1. paul_wiedefeld | | #116

          It's more the ratio: the lowest end furnace + AC quote I received was about $15 USD over the lowest end heat pump, just a fraction of a percent more. It seems contractor enthusiasm matters.

  32. shtrum2 | | #117

    We’re all born with this thing between our ears to make our own judgments. But those judgments get stronger with diverse opinions; one doesn’t necessarily have to be an expert to offer meaningful commentary, and there’s always people in this forum who have the experience/background to add corrections where necessary (I especially value Dana Dorsett’s contributions . . . although his explanations admittedly leave me reeling sometimes 😃). So my commendation to GBA for allowing a variety of points of view, and making all of us a little bit smarter . . .

  33. ukretro | | #118

    Excellent debate. Looking at Whole Life Carbon (WLC) in a UK context suggests that with the refrigerants used to date and their leakage rates, a gas boiler has been little worse over the whole of its life than a heat pump, according to Lets hope that CO2 and other low CO2e refrigerants come along more widely in the future. Or is our UK context unusual perhaps, given that we largely have hydronic heating already and relatively little cooling need in our maritime climate, so our heat pumps tend to be air to water?

    1. Jon_R | | #119

      Its the right kind of analysis. But IMO their high scenario leakage rate is much too high and COP is too low for residential heat pumps. And PassivHaus energy usage skews the FIg 2 numbers. So give substantial preference to a heat pump installed now. And in any case: "after 2022, ASHP and VRF should now have significantly lower WLC than natural gas boilers..."

      1. ukretro | | #120

        Indeed. Roll on 2022. Until then I might hang on to my 42-year-old Vulcan Continental gas boiler, despite its no-doubt-appalling inefficiency. Even including a pilot light which according to my recent measurement of our gas use when on holiday for a week with no gas usage for any other purpose was 30,000 btu per day (if that sounds possible. We deal mostly in kWhrs and it was 8.8 of those). I shall now turn it off, pilot light and all, for the summer. Then when we re-light it in the autumn I will have to mop up the pool of water which will accumulate, due to leaks between the cast iron sections, until they seal themselves again after a day or two.

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