Calculators
How many years until solar pays back?
Adjust consumption, system size, price and subsidy. The calculator estimates generation, savings and payback including panel degradation and price growth.
Common questions
How much does a home solar system generate?
The calculator starts from 1000 kWh per installed kW a year. Your installer's quote should give an expected figure for your roof and location, so enter that. South-facing panels generate the most in the US; north-facing or shaded roofs generate noticeably less.
Is there still a federal tax credit?
Not for a system you buy. The IRS says the Residential Clean Energy Credit (25D) does not apply to expenditures made after December 31, 2025, and an expenditure counts as made when installation is completed. Leases and PPAs are handled differently.
What is self-consumption and why does it matter?
The share of your solar output you use yourself. Each kWh you use saves your full retail rate, while exports earn whatever your state's net metering or net billing rules pay, which can be far less. A battery or daytime usage raises it.
Is net metering still available?
It depends on your state and utility. California moved new customers to net billing in 2023, and other states set their own rules. Ask your utility how exports are credited before you size a system.