In Missouri, a 9.2-kW system for an average home costs about $23,008 after incentives in 2026, saves about $1,777 in the first year and pays back in 11.1 years.
| Item | Amount |
|---|---|
| Solar, 9.24 kW × $2.49/W | $23,008 |
| Federal credit (0%) | $0 |
| Net cost | $23,008 |
| Scenario | Net cost | Year-1 savings | Payback | 25-yr net |
|---|---|---|---|---|
| State averages (above) | $23,008 | $1,777 | 11.1 yr | $39,298 |
| Rates rise 5.6%/yr (2020–25 pace) | $23,008 | $1,777 | 10 yr | $64,566 |
| Rates stay flat | $23,008 | $1,777 | 13 yr | $19,987 |
| Survey price $3.6/W (LBNL) | $33,264 | $1,777 | 15.2 yr | $29,042 |
| Add 13.5-kWh battery | $37,979 | $1,777 | 17 yr | $24,327 |
| Exports cut to 50% of retail | $16,434 | $917 | 15 yr | $14,829 |
Verdict: at average Missouri numbers, solar is a solid investment in 2026 — payback takes 11.1 years, leaving you $39,298 ahead after 25 years. The main reasons: 1:1 net metering, which credits every exported kWh at the full retail price. Pay cash if you can: Berkeley Lab found loan-financed systems priced about $1.50/W above cash installs in 2025, which can add years to the payback.
Net metering and exports in Missouri: Net metering required at >= avoided fuel cost; Evergy 1:1, Ameren pays 5.39¢ (summer) / 3.92¢ (winter) for excess.
Battery: a 13.5-kWh battery at the Missouri average of $1,109/kWh adds $14,972 and saves almost nothing extra under 1:1 net metering — buy it for backup, not payback; payback becomes 17 years.
EnergySage's Missouri page lists a 17.2-year payback. Its method is not fully published; ours uses EIA's Jan–Aug 2026 price, 1:1 net metering, 3%/yr rate growth and 0.5%/yr panel aging, with no federal credit.
The full method, material data and tips are on the main solar payback calculator page.