On average, a 10kW solar energy system costs roughly $29,935 before any tax incentives or rebates are applied. If you qualify for the federal solar tax credit, though, it can reduce your net investment by 30%, lowering the average 10kW system's cost to just $20,954. That is about 1,000 to 1,500 kWh per month, or about 12,000 to 18,000 kWh per year. Here's what affects the production: Location: In sunny states like Arizona or California, your system will produce more power. We'll outline everything you need to know about 10kW solar systems below, including how much they cost, what they can power and how to determine if a 10kW solar energy system is right for you.