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Solar economics, explained without the installer pitch
Every article here pairs with a calculator on this site. Concept on the left, math on the right — both written by a solo operator, both cited to primary sources (DSIRE, NREL PVWatts, IRC §48E, IRS Form 5695, EIA Form EIA-861), both reviewed on a quarterly cadence. IRC §25D expired January 1, 2026. The math doesn't disappear — it shifts to state incentive stacking, financing comparison, and 25-year NPV modeling. This is launch content; more articles are in progress.
Anchor articles available now: “Solar panels in 2026: the complete guide after §25D expires”, “State solar incentives in 2026: what's still available” , and “Did you install solar before Dec 31, 2025? Claim your §25D credit”.
State Incentives
State solar incentives in 2026: what's still available after the federal credit ends
§25D is gone but DSIRE tracks 3,000+ active state and utility programs that remain. Massachusetts, New York, and California homeowners can stack credits worth more than the old federal 30%. Here's the operator-grade state incentive map for 2026.
Updated May 23, 2026 · Pairs with /calculators/state-solar-incentive-stacker
Did you install solar before Dec 31, 2025? Claim your §25D credit before it's gone
Solar installed before Dec 31, 2025 still qualifies for the full 30% §25D federal credit — but you must claim it on Form 5695 on your 2025 return. §25D has no carryforward. If you don't claim it this cycle, it's gone. Here's the exact form-level walkthrough.
Updated May 23, 2026 · Pairs with /calculators/solar-payback-npv