Updated 24 March 2026

Solar vs Grid Electricity: 25-Year Cost Comparison

Solar panels lock in your electricity rate for 25+ years while grid prices rise 2-3% annually. Here is the maths.

The Core Comparison

FactorSolarGrid
Cost per kWh$0.06-$0.08 (fixed)$0.16 (rising 2-3%/year)
Upfront cost$14,000-$21,000 (after credit)$0
25-year total cost$14,000-$21,000$55,000-$85,000
25-year savings$35,000-$65,000$0
Price predictabilityFixed for 25+ yearsIncreases every year
Home value increase+$15,000-$25,000$0

25-Year Cost by State

Based on average home usage (886 kWh/month), 7 kW system, 30% federal tax credit, and 2.5% annual grid rate increase:

StateGrid Cost (25yr)Solar CostSavings
Hawaii ($0.43/kWh)$162,000$18,000$144,000
California ($0.30/kWh)$113,000$16,000$97,000
Massachusetts ($0.28/kWh)$106,000$17,000$89,000
New York ($0.24/kWh)$90,000$16,000$74,000
Florida ($0.16/kWh)$60,000$14,000$46,000
Texas ($0.14/kWh)$53,000$15,000$38,000
Idaho ($0.10/kWh)$38,000$16,000$22,000

The Payback Timeline

Years 1-7: Payback phase

Your monthly savings ($100-$250) gradually repay the upfront cost. With the 30% tax credit applied in year 1, most homeowners break even in 6-9 years.

Years 8-15: Pure savings phase

Every dollar of electricity your panels produce is profit. Meanwhile, your neighbours' grid rates have risen 20-40% since you installed. The gap widens every year.

Years 16-25: Maximum value phase

Grid rates are now 50-80% higher than when you installed. Your panels still produce 85-90% of their original output. This is where the big savings accumulate.

What About Panel Degradation?

Solar panels lose about 0.5% efficiency per year. After 25 years, they still produce 87-90% of their original output. This is already factored into the savings above.

Most panels come with a 25-year warranty guaranteeing at least 80% production. Many panels last 30-35 years in practice.

The One Scenario Where Grid Wins

If you plan to sell your home within 3-5 years, the payback math does not work as well. However, solar adds $15,000-$25,000 to home resale value (Zillow data), which partially or fully offsets the installation cost. You may break even on the sale even without reaching payback through electricity savings.

The verdict: Solar beats grid electricity in 48 out of 50 states over 25 years. The only question is how fast it pays back. In high-rate states, you are leaving money on the table every month you wait.

Calculate your solar savings

See your payback period, 25-year savings, and cost per kWh.

Use the Calculator →