In Rhode Island, a 5.7-kW system for an average home costs about $6,521 after incentives in 2026, saves about $1,959 in the first year and pays back in 3.2 years.
| Item | Amount |
|---|---|
| Solar, 5.72 kW × $2.79/W | $15,959 |
| Federal credit (0%) | $0 |
| State incentive | −$9,438 |
| Net cost | $6,521 |
| Scenario | Net cost | Year-1 savings | Payback | 25-yr net |
|---|---|---|---|---|
| State averages (above) | $6,521 | $1,959 | 3.2 yr | $63,979 |
| Rates rise 5.6%/yr (2020–25 pace) | $6,521 | $1,959 | 3.1 yr | $92,831 |
| Rates stay flat | $6,521 | $1,959 | 3.3 yr | $41,961 |
| Survey price $3.5/W (LBNL) | $10,582 | $1,959 | 5.1 yr | $59,918 |
| Add 13.5-kWh battery | $19,170 | $1,959 | 8.7 yr | $51,330 |
| Exports cut to 50% of retail | $4,514 | $1,020 | 4.2 yr | $30,268 |
Verdict: at average Rhode Island numbers, solar is a strong investment in 2026 — payback takes 3.2 years, leaving you $63,979 ahead after 25 years. The main reasons: electricity that costs more than in all but 5 states; weak sun (the 8th-lowest yield of 51); 1:1 net metering, which credits every exported kWh at the full retail price; a state incentive worth about $9,438. 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 Rhode Island: Retail net metering up to 100% of usage; excess at avoided cost (cap 125%).
Battery: a 13.5-kWh battery at the Rhode Island average of $937/kWh adds $12,650 and saves almost nothing extra under 1:1 net metering — buy it for backup, not payback; payback becomes 8.7 years.
EnergySage's Rhode Island page lists a 9.6-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.