Most homeowners spend between $12,600 and $33,376 to install a complete residential solar system in 2026, with the national average at $19,873 before incentives. Your actual cost depends on your home's energy needs, roof characteristics, location and other factors, all of which we'll break down in. How much you pay to go solar will depend on six factors, including your electricity usage, how many solar panels you install, the incentives you use, and the installer you choose. This typically translates to about $2. 50 per watt of installed capacity (more on price per watt below). Federal Tax Credit Urgency: With Congress proposing to end the 30% federal tax credit after 2025, homeowners. Solar panels cost $3. 75 per watt before factoring in available solar incentives.