Over on the Hijack thread RTH noted the lack of a solar thread, so I figured I would start one. The Two Bit DaVinci video description of solar options is worth the 20-minute view if you don’t know about solar.
We have solar here at Maybelot. It went on line on 6 December, so it hasn’t been a full month yet. We have 45 panels, with 19.3 kWp peak generating capacity (that’s the limit our electric cooperative - our electric company, or the co-op) allows a private generator to feed to the grid. We have two Solar Edge inverters.
Here’s how it works: Our system generates DC current. The inverters convert it to AC, and send it to the panel. Our house uses what it uses, and any excess goes to the co-op. When our house uses more power than we’re generating, we draw from the co-op. The meter measures what the co-op delivers to us, what it has received from us, and the net difference. This month, we’ll pay because the co-op delivered more than we used. As the days get longer and sunnier (and we make our house more energy efficient by adding things like insulation - I swear, I don’t know how the previous owners didn’t freeze to death), the system will make more power, and we’ll eventually make more than we use in a month.
When that happens, the excess power will be carried over in the form of credit which, for our co-op at least, always accrues and never expires (some electric companies reset at the end of each year, and may or may not pay you for the excess, and if they do pay, they may or may not pay you the same rate you would have paid them). Eventually we should have enough credit built up from the summer months to carry us through the winter.
Then there is “renewable energy credit.” REC is your system’s generating capacity. The capacity is a commodity that can be sold on the open market. Electric power companies and co-ops are required to certify to the government that a certain percentage of the power they deliver comes from green sources. Some companies allow the individual customer to elect green power, although they charge more for it (which, considering that they’re basically getting it for free is kind of a rip-off, IMO, although it does incentivize the production of green power). Anyhoo, our little generator, and the thousands of others like it, when combined together, are a significant enough source of green power to make companies with reporting requirements want to call dibs on it. They bid for the right to claim our power, and working that process is one of the services our installer provides. They’ll skim a little off the top and we’ll get a check (not a ton of money - $500 to $1K maybe?). It’ll help to offset the cost.
This system cost $50K. Twent-six percent of that - $13K - will be deducted from our federal taxes, so the net cost is really $37K. We anticipate about a 10-12 year payback.