Again, I’m not savvy to all solar but I do know there’s a point at which it’s just not worth it. At that point unless I wanted to burn money, it simply doesn’t make sense. (I’m not independently wealthy, just have enough money to do it comfortably if I want to). I just think that based on previous conversations I’ve had with folks, you really need something above $200/month to have solar be worthwhile? 🤷♂️ (I rarely go over $200). But it’s also been a few years once I’ve discussed it.
And the one other thing I know is that I’ve got a roof facing due south in so cal that would make a solar mfgr probably salivate at the thought of slapping panels on it. But also again....maybe I’m wrong. 🤷♂️
The idea of there being a dollar figure above which it's worth it and below it is not is a fundamental misunderstanding of well, basically everything.
As a start, do you have detailed power use data for your home? At minimum you'd want what is on your power bill - How many kwh per month have you used over the last year? How many do you anticipate using in the future (EV)? What is your average cost per kwh? Do you have time of use rate plans available where you are? Does net metering exist where you are?
While you are collecting all that data go here:
Estimates the energy production and cost of energy of grid-connected photovoltaic (PV) energy systems throughout the world. It allows homeowners, small building owners, installers and manufacturers to easily develop estimates of the performance of potential PV installations
pvwatts.nrel.gov
That will give you an idea of the generation potential of your roof. You'll need to know the pitch of your roof and the azimuth.
So once you have all this data the question then is:
1) How much of your monthly use will a PV system cover?
2) How much does that system cost?
3) How much tax credit and/or production credit will the system generate to offset cost?
4) What's your net cost of the system divided by the total kwh you can expect it to produce over its useful life?
If the answer at the end is lower than the cost per kwh you pay from your utility now and expect to pay in the future (decide on a % escalator because energy prices in general go up) then it's at least viable at quick inspection.
A solar installer can do all of this math for you but you need to understand how it works and know enough about it to know when they are using numbers that are skewed in their favor (unrealistic escalators on grid pricing for example). If you spend a few hours doing your homework you should be able to produce production estimates very close to what the solar installers will do for you. You don't have to talk to anyone to get a really good idea of what to expect when you do.
If you're willing to share data and/or address there are plenty of people out there who will help you.
Viper GTS