Solar vs Grid-Only: 25-Year Cost Comparison

A US household using 10,800 kWh per year at 0.17 dollars per kWh pays 1,836 dollars annually. With 4% rate inflation, that grows to 4,920 dollars by year 25 and totals 76,500 dollars over 25 years. Same household with an 8 kW solar system covering 80% of usage: net install 16,800 dollars after ITC, plus 25-year residual electricity cost of ~15,000 dollars, plus inverter replacement at year 13 (~2,000 dollars). Total 25-year cost with solar: ~33,800 dollars. Net savings: ~42,700 dollars. Plus ~50 tonnes of CO2 avoided.