Rooftop solar installation typically costs about $23,100, with most projects ranging from $19,100 to $23,800 depending on system size and location. Under current federal law, the Residential Solar Tax Credit (ITC) ended for customer-owned systems on December 31, 2025. Solar Costs Have Reached Historic Lows: Average residential solar costs have dropped to $3. 30 per watt in 2025, representing a 60% decrease from 2010 levels. Combined with the 30% federal tax credit extended through 2032, most homeowners can achieve payback periods of 6-12 years with 25+. The cost associated with rooftop solar power generation varies significantly based on several factors, with key elements such as 1.