I've done a similar build out in my Northern Lite camper. 800w on the roof and 400ah of lithium. I want to convert the fridge to an electric compressor fridge and the stove over to induction next. I hate it when the batteries fill back up by 10am and I waste solar meanwhile I am still buying propane for the appliances.
The gas analogy isn't very good because cars are very inefficient at turning gas into power. So it's substantially more than 31 gallons worth in a car.
My city (San Francisco) has a program where you can elect to get 100% of your power from renewables which are primarily hydro, solar, and wind and it comes out cheaper every month than buying power from PG&E. It's pretty great.
So, those sort of programs are confusing and often pretty misleading. First off, you can't choose which electrons go to your house of course; all you can do is draw power from the grid. That's fine, it doesn't really matter at the end of the day, but more importantly most of those programs work by purchasing "renewable energy credits", or RECs, from wind and solar farms across the country. So what does that REC mean? Well nothing really, it just means you "claim" credit for that kWh of renewable energy. If you want you could buy them directly from some random wind farm in Kansas in theory. Or buy for twice as many kWh as you actually use- now you're 200% renewable and you're sucking carbon out of the air! Oh wait.
At the end of the day, RECs are a good idea because they provide an additional revenue source for renewable energy producers, but it isn't all that much. Last I checked they sell at like 3% of what the energy actually sells for on the grid. So for example if a wind company sells electricity for 20 cents a kWh to the grid operator, they could separately sell the RECs for that power on the open market for something like 0.6 cents per kWh, if the grid operator doesn't want the RECs for themselves as part of the power purchase agreement.
I myself subscribe to Arcadia, which is one of those companies that promises to make your power 100% green via purchase of RECs. I consider that to be false advertising. But, I still do it because it does help drive the market for RECs which is good because the ability to sell RECs makes producing green energy a bit more viable, which in turn hopefully spurs growth in the industry.
So in conclusion, it's a good thing to do, but not as good as you might think based on how it's presented. Sorry for the wall of text.
It's still just too unaffordable for many people. It would cost us over $10,000 to get panels installed and that doesn't include the multiple trees that would have to come down because they are really old oak trees with huge branches that stretch over the house and sometimes fall on the roof.
There should be much bigger subsidies. That wouldn't help us, but it would help a lot of others.
Only if or when storage becomes cheap and widespread, otherwise even if you produced 100x the energy when the Sun shines you'd still need some other source of energy for the rest of the time. There are some glimmers of hope but they perpetually seem 4-5 years out.
I have 10kwh of storage, which helps a lot, and it wasnt that expensive, especially compared to a few years ago.
Now that sodium ion batteries are actually starting to become available we will see them taking over stationary storage, but for now LiFePo4 works pretty good.
how much do you invested in your solar system? I'm trying to convince my wife to install a solar roof (no battery), but I'm doing the math and it would take 8-10 years to barely break even (if nothing critical breaks down during that time).
$16K in parts, PE drawings and tree removal. With 30% of that back in tax rebate. I did the install myself with help from my wife. 11.64KW DC worth of panels. Anything more than 11.7KW and I would have gone from class 1 to class 2. I didn't want to deal with all that required.
My degree is in computer engineering and I used to work in power generation so I was very comfortable with the electric design and working with high voltage and current. You might not be so comfortable. A similar system without battery was quoted to me at $24K by an installer.
Battery was about $2K. Tree was $1K. After rebate cost was $11.2K. It's reduced my power bill by about $210 a month. So about 4.4 years to break even.
It was a lot of work on my end but I know I didn't cut corners and was very careful to make a system that should last.