NEM - Net Energy Metering - this is how your utility "settles" up with you. I.e. it would be really nice for the *consumer* that when you generated excess power, you would get the FULL retail rate, because then you can offset pulling power from the utility company at night, when it's cloudy, etc. But it's obviously unrealistic to expect the Utility company to be an "infinite battery" for consumers as it is totally unsustainable. Much more typical these days is the utility company will pay you *wholesale* (or less!) rates when you generate excess but charge you *retail* rates when you need to pull from the grid. The arrangements can be pretty complicated -
see if you can figure out what is "best" to do with Xcel Energy per this form?!? Note that their "payback" rate is about 1.5 cents/kWh ... whereas retail prices are about 14 cents/kWh ... and can be much higher with TOU pricing. You hear a lot about how electrical rates influence the economics of Solar, but I'm increasingly convinced that NEM will have a bigger effect ... plus that can change somewhat quickly - albeit there (hopefully) will be some grandfathering. There's good reasons why Hawaii has completely dropped NEM and other places are moving in that direction ... and
California will probably change the rules for existing customers -
fact sheet here.