I thought I read somewhere that solar panels only last 20 years. It doesn’t seem worth the cost to me.
and
home solar system doesn’t make good economic sense. Of course, if they raise the rates high enough, maybe it would.
It depends a lot on your situation and if you do your homework. For example, without selling power to the grid I was slated for my home energy project to pay for itself in 12 years, with my solar panels having 25-year/70% throughput warranties (guaranteed to have only a small loss in throughput each year so that on the 25th year they'd still be producing 70% as much power). My batteries have a 19-year/50% warranty.
I installed some of them in spring 2021, liked it, and adding on to it in the fall of 2022 to make the full version I wanted (but only after I made sure the smaller version worked as well as expected). And after having the full system for a year (and seeing how it handled my now all-electric home, including charging the EV for 16K miles per year of home charged miles, and handled the changing seasons), I calculated when my payback point was. That assumed the aforementioned degradation of throughput, and also a 3% inflation rate in the power rates I mostly avoid. The payback point is 12 years after the 2021 install (11 years after the 2022 upgrade).
And all of that was without selling power to the grid. I recently started selling power to the grid. In my state there are extra fees us solar users have to pay if we sell power to the grid. Plus, the rate we get per kWh for selling is usually 1/5th to 1/4th the rate we pay per kWh for buying power. So I recommend anybody considering solar to plan on not ever selling power to the grid (which means your payback math is based only on saving power, not selling power, and also means you'll buy inverters with the option to turn off grid-sell like mine have). Then only after having solar for a year and seeing how well it performs in all seasons do you crunch the numbers and decide if selling power to the grid makes you more than the extra fees. Otherwise it's best to not sell to the grid and just be a normal residential power consumer like everybody else (only don't pull from the grid as much because your solar saves you power).
But you MUST do your own homework first. And don't forget other energy saving techniques such as caulk-sealing cracks, adding gaskets around doors, adding insulation, replacing old HVAC and water heater with more efficient ones. In my case, because I live in the south it made economical sense to convert my two natural gas appliances to electric (but only because I can produce homemade power, I wish I could produce homemade nat gas).
One thing to keep in mind is that you have to increase your home insurance coverage. My insurance doesn't have a solar fee. But I raised my premiums when I raised my coverage amount because if a tornado comes (in Alabama we call it "tornado insurance" instead of "fire insurance" LOL) I'll need more coverage to not only rebuild the house, but replace the solar system. Another thing to keep in mind is if you put the panels onto your roof, you have to consider the years left on your shingles (I have a fairly new metal roof that ought to outlast my 25-year warranty solar panels).
And of course, there's the solar tax credit (I hate it both because I hate the govt messing with the market and I hate that it artificially inflates the upfront prices I had to pay). The 30% credit is non-refundable, but does carry forward. In other words, I haven't received all of the tax credit yet, only part of it. When I file my taxes a year from now it'll get the remaining portion of my credit. I use that solar tax credit refund to pay down on the HELOC I took out to buy and install the solar equipment, install upgraded HVAC and water heater, and help make payments on the EV.
So there's a lot to take in. Last but not least is an analysis of how much power you consume on a regular day, how much that changes in the seasons, and how much peak solar hours you get per day in your area (and how that changes in the seasons). YOU HAVE TO DO YOUR HOMEWORK.
But it works for me. In the past 366 days, 80.7% of all of the power we consumed was from homemade power. That includes charging the EV for 15K miles of the 25K miles we drove it in the past 12 months (not counting the 10K miles we charged elsewhere). That means that when the Dims at the national level mess up energy costs, it impacts our budget only in the 20% of power we buy from the grid, plus gasoline cost for what little we drive the gas pickup, plus long trip driving costs (either gas or power, depending on which car we take). It's a sweet feeling to have my quasi-retired budget not have to worry about future energy policies having much impact on our long-term financial planning.