50 per watt installed on average, with homeowners spending about $3. A 6- to 10-kW solar panel installation costs $12,600 to $31,500 after the 30% federal tax credit. . Average price of solar modules, expressed in US dollars per watt, adjusted for inflation. Data source: IRENA (2025); Nemet (2009); Farmer and Lafond (2016) – Learn more about this data Note: Costs are expressed in constant 2024 US$ per watt. Global estimates are used before 2010; European market. . NLR analyzes the total costs associated with installing photovoltaic (PV) systems for residential rooftop, commercial rooftop, and utility-scale ground-mount systems. This work has grown to include cost models for solar-plus-storage systems. Your actual cost depends on your home's energy needs, roof characteristics, location and other factors, all of which we'll break down in. . Solar panels cost about $21,816 on average when purchased with cash or $26,004 when purchased with a loan for a 7. is between $15,000 and $25,000 before incentives.