It depends, $180/mo for 25 years is the agreement and it’s directly connected to the grid both ways which required additional work from the power company to inspect and approve. I think given the projections it was rated for about 25,000 kWh per year * 25 years (approaching 85% efficiency after 30 years), which is a good amount of total production for my needs. Edit: it’s worth considering what $180/mo will look like in 5 to 20 years… it will probably be significantly cheaper compared to other power sources because it’s generated locally.