If you have an old analogue meter it will run in reverse, but this is illegal (you are reducing your metered usage of grid electricity, but the price of that in

If you have an old analogue meter it will run in reverse, but this is illegal (you are reducing your metered usage of grid electricity, but the price of that includes grid transmission costs, taxes etc). The modern ones have a separate meter if you want to feed it to the grid, but it's not worth it, there are some fees for that so you'd end up with a few bucks every year. So the way it works, you plug it in, and your appliances can use it and not the electricity from the grid. The excess you don't use gets fed in the grid, generally for free. You save basically on all the taxes, transmission costs etc, which are the majority of the price, if you use your own electricity. The more you can use, the more you will save.