State Solar Incentives After §25D Ended

Overview

With the federal residential credit gone, state programs are no longer a bonus on top of a federal benefit — for many households they are the entire incentive stack. The problem is that state programs are numerous, capped, funding-limited and frequently revised. This page lists only what we could verify in November 2026, separates credits we model from production incentives we do not, and explains why a program you read about may not be one you can actually claim.

Credits and grants we model

New York: 25% of qualified solar cost, capped at $5,000, with a carryforward. Massachusetts: 15%, capped at $1,000. Arizona: 25%, capped at $1,000. South Carolina: 25%, capped at $3,500. New Mexico: 10%, capped at $6,000. Utah, Montana and Iowa: flat credits up to roughly $1,600, $1,000 and $5,000 respectively, with Iowa's described as funding-limited. Each is applied to the array cost, not the battery, and each is capped at the statutory maximum. Where a state is not on this list, our model uses $0 and says so.

Production incentives we do not model

New Jersey's SuSI / ADI program pays per MWh for a fixed term; Massachusetts SMART pays per kWh; Illinois Shines pays an upfront REC amount; Connecticut RSIP, Colorado utility programs, North Carolina PowerPair, New York's NY-Sun per-watt rebates and California's SGIP battery incentives are all territory-, block- or eligibility-dependent. Folding a guess into a 25-year model would be worse than leaving it out. If you have a confirmed dollar amount, enter it as a utility rebate.

Tax exemptions that are easy to miss

Sales-tax exemptions reduce the purchase price at the point of sale, and property-tax exemptions prevent an assessment increase from the added value. Both are real value, neither is a rebate check, and availability varies by state and sometimes by locality. California's property-tax exclusion for solar has a sunset that was a live issue in 2026 — confirm the current date with your installer.

How to verify

Start with DSIRE (dsireusa.org), then your utility's program page, then your state's tax authority for the credit form and cap. Ask the installer to put the program name, statutory cap, and who claims it in writing. A proposal that lists an incentive without a program name is not a number you can rely on.

Key figures worth keeping

• $5,000 — the cap on New York's 25% state credit.
• $1,000 — the caps on Massachusetts' 15% and Arizona's 25% credits.
• $3,500 — the cap on South Carolina's 25% credit.
• $6,000 — the cap on New Mexico's 10% credit.
• 8 — the number of states with a credit or grant verified and modeled in this build.

How this shows up in a real estimate

The state layer is now the whole incentive layer, so a small change in a cap can matter. On a $20,000 array, New York's 25% credit would be $5,000 before the cap and $5,000 after it — the cap binds. On a $30,000 array it also binds at $5,000. Massachusetts' 15% reaches its $1,000 cap on an array of only about $6,667, so for most real systems the cap is the number that matters, not the percentage. HelioCalc applies min(percentage × array cost, cap) and shows the resulting dollar amount in the itemized cost table rather than quoting a headline rate.

Checklist before you decide

• Find the program name and statutory cap, not just a percentage.
• Confirm whether the credit is refundable or carries forward.
• Check whether it applies to batteries or only to the array.
• Verify funding availability and waitlists before counting a rebate.
• Enter only confirmed dollar amounts in the utility rebate field.