$12K Net Solar Cost → 6-Year Payback → $55-$75K of Real 25-Year Savings
7kW residential system in 2026: $18-22K gross, $8-15K net after federal 30% ITC + state incentives. ~$2K/year savings → 6-year payback. Then 19+ years of essentially free electricity. Math depends entirely on local sun + rate.