I'm not sure about the US as installation costs there are very expensive, but in my part of Europe I had 10kW of roof mount solar installed for €10,800 at the end of last year.
The calculations I did for it in 2020 were that the payback period would be 7 years, or 6 with government incentives. That was when electricity was 15c/kWh though... if energy prices stay at the current level I will break even in less than 4 years. I generate around 8000kWh a year, which at current prices is €3200.
The panels should last forever (assuming no physical damage from hail storms etc), they just decrease in efficiency. The inverter should last at least 10 years, but that's easy to replace as it's not on the roof.
The calculations I did for it in 2020 were that the payback period would be 7 years, or 6 with government incentives. That was when electricity was 15c/kWh though... if energy prices stay at the current level I will break even in less than 4 years. I generate around 8000kWh a year, which at current prices is €3200.
The panels should last forever (assuming no physical damage from hail storms etc), they just decrease in efficiency. The inverter should last at least 10 years, but that's easy to replace as it's not on the roof.