Solar / PV panels
I note that in the detail pages and list of categories on the GBA site, there is nothing labeled “solar panels.” I see “Solar hot water,” but nothing about solar/PV panels in general. Although I have seen articles about solar/PV panels, this makes me wonder if GBA is not in favor of them?
My daughter and son-in-law in Pocatello, ID, are having a salesman come over to talk about solar panels, and she’s asking me for advice.
With an 1950’s era house that has not had any significant/observable energy retrofitting/weather stripping/insulation, etc., I wonder if their money would be better spent on those sorts of effort? Anyone have an opinion on spending money on solar panels versus basic energy efficiency measures? Also payback on solar panels…
thanks!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Vince,
Links to articles on photovoltaic (PV) systems can be found on this index page: "Photovoltaic systems."
That index page has links to 17 articles, but if you poke around on the GBA site, or use the "search" box, you'll find many more similar articles.
Without knowing more about the current condition of the house and the HVAC system/configuration it's hard to say where the crossover point is to where rooftop PV becomes the better investment. If the house leaks a lot of air and has single panes/no-storms ther
The cost of air sealing and retrofit-insulating and even if adding low-E storm windows (which brings the performance of wood-sash single panes pretty close to current code minimums at much lower cost than replacement windows) is substantially less than 5kw of solar if it's all paid directly out of pocket. Different solar companies have different financing options that might make it attractive enough on a longer term basis, spending the out-of-pocket cash on fixing the deficiencies of the house.
One thing to watch out for with solar sales-droids is the insane electricity price inflation models showing HUGE lifetime savings. It seems like "6% per year" is a commonly used number, but it's utter BS. Electricity rate inflation has been BELOW the general rate of inflation over the past 30-60 years, despite shorter term "noise" in the price signal. If there is a year on year price esclation clause of more than 2%, walk away from the deal.
If you have a 50's vintage house and have made no energy efficiency improvements, I think you'd get more bang for your buck doing an air sealing and insulation retrofit project than you would from a solar install. You can do the solar project later to gain even more, but I personally would do the air sealing and insulating work first.
Exactly how much you'll get out of a PV system depends a lot on where you are (how much average sun you get throughout the year, what your average weather is like, etc.), and the payback will be very different depending on how much you might be able to get in terms of incentives like tax writeoffs. Your PV sales people will know about any incentives.
Bill
FWIW: Idaho Power (serves Pocatello) has rebate incentives for higher efficiency HVAC and other equipment, subsidizes Home Energy Audits, and will rebate $350 for duct sealing. But no direct weatherization subsidies seem to be currently available:
https://www.energy.gov/savings/idaho-power-residential-energy-efficiency-rebate-programs-0
There at least used to be a Home Improvement Program that would subsidize weatherization and windows if the house is heated electrically, but the links to those on the Idaho Energy Code website appear to dead-end:
https://www.idahoenergycode.com/incentives