After driving a Prius for 19 years, last year we switched to an EV--a Chevy Bolt. It is great. We will never go back to a gasoline car. This year we had Sun's Free Solar install solar panels on our roof., which faces SSW--ideal for solar generation. The cost of installing 10 400w panels including the federal tax credit was $11,800. Now our panels more than cover our electicity usage, including keeping our car charged.
AMP's tiered electricity charge is 11.1 cents per kwh for level one, 17.9 cents for level two, and 27.2 cents for level three. If you drive your EV quite a lot and you move into level two or three, your electricity bill can go up considerably, even if you charge at night. It is still considerably cheaper, however, than filling your gas tank.
Electricity we do not use that is generated by our solar panels goes to AMP, which credits us at 6.9 cents/kwh. Therefore, we now charge our car during sunlight hours so we are using our own solar power rather than AMP-supplied power. There are two benefits to this: 1) Our rate for AMP-supplied power during non-sunlight hours never exceeds AMP's first tier (11.1 cents/kwh).; and 2) The value of the solar power we generate and use is equivalent to 11.1, 17.9, or 27.2 cents/kwh rather than the 6.9 cents/kwh we get if we send the power to AMP.
I estimate we will recoup the cost of our solar panels in 11 to 15 years. The lifetime of the panels is at least 30 years. But the most important think to us is that we are helping to support carbon-free transportation. I still mostly ride a bike instead of driving.