Rhode Island is the only state in this calculator where the first decision isn't a number — it's a path. RI homeowners choose at install between two mutually exclusive incentive structures, and once you enroll in one, you forfeit the other for the life of that contract. Read this section before sizing a system; it changes everything that follows.
Path B (Net metering + REF grant). Self-consumed solar offsets full retail (about $0.29/kWh — one of the higher rates in the US, New England grid). Exports get 80% of retail (about $0.232/kWh) — a 20% haircut from full 1:1, applied to systems interconnected after April 15, 2023 (earlier systems are grandfathered into 1:1). On top of that, the Renewable Energy Fund (REF) grant from Commerce RI pays $0.65 per Watt upfront, capped at $5,000 — a cash discount at install, NOT a tax credit.
Path A (REG production tariff). The Renewable Energy Growth program pays $0.2723/kWh (PY2026 ceiling) on ALL the electricity your system generates — self-consumed and exported, not just exports — for 15 years, locked at the rate when you enroll. During the REG contract you do NOT use net metering and CANNOT take the REF grant. After 15 years your system reverts to the standard 80% net metering (years 16–25 in our 25-year model).
These programs cannot stack. The state's Office of Energy Resources phrases it directly: choose one at install. For many small residential systems the REF/net-metering path pays back faster (the upfront grant moves a lot of cash forward); for larger systems and longer-horizon math, REG often wins because it pays for every kWh you generate for 15 years.
What changed (and what RI's own state site is still wrong about)
The federal Residential Clean Energy Credit (§25D) — the 30% homeowner credit — was repealed for systems installed after December 31, 2025. For 2026 Rhode Island buyers, the federal credit on a purchased system is $0. The same applies to home batteries purchased outright. The §48E commercial credit (30%) still exists, but only for leased or third-party-owned systems where construction begins before July 4, 2026 — and the lessor claims it, not you. Full federal context here.
The repeal came through the One Big Beautiful Bill Act (P.L. 119-21), signed in July 2025. Most aggregator and installer sites have not updated. In Rhode Island specifically, even the state's own Office of Energy Resources page on solar has not been updated to reflect the repeal as of mid-2026. If you see "30% federal solar tax credit" on a 2026 RI solar quote — or on the OER page — that math is outdated. Verify with IRS.
Path B: Net metering + REF grant
This is the default path for most RI residential solar buyers, and the one we model first in the calculator. The math is straightforward and the cash arrives early.
Net metering on RI Energy (post-April 15, 2023). Self-consumed solar offsets your full retail rate; exports are credited at 80% of retail — a 20% haircut from the older true 1:1 structure. Concretely, at a retail rate of about $0.29/kWh, exports earn about $0.232/kWh. Net metering terms are protected by state law through 2039, which is unusually long-tail protection compared to states like Washington (PSE moving away from 1:1 in 2026) or Pennsylvania (PPL filing a similar shift). Year-end surplus (each March) settles at avoided cost — about $0.03–0.05/kWh — far below retail, so don't oversize. Size to at most 125% of your annual use.
Two utility footnotes that matter if they apply to you:
- Pre-April 15, 2023 systems are grandfathered into the older true 1:1 export crediting at full retail. If you already have one, the 80% haircut doesn't apply.
- Pascoag Utility District and Block Island Power Company are small municipal utilities that still offer true 1:1 full retail net metering. They are not on the RI Energy tariff and not modeled in the calculator — if you're a Pascoag or Block Island customer, your export math is materially better than what this article describes.
The REF grant. Rhode Island Commerce administers the Renewable Energy Fund (REF), which pays a flat $0.65/W upfront for net-metered residential solar, capped at $5,000. Structure that matters:
- Upfront cash discount, not a tax credit. Applied directly to your install cost; you don't need state tax liability to use it, and you don't wait for a tax-time refund.
- Path B only. REF cannot be combined with REG enrollment. If you go REG, you lose REF eligibility for that system.
- Battery adder: $2,000. If you pair a battery with your solar install, REF adds $2,000 to the grant.
- The cap binds at systems above about 7.7 kW: a 5 kW system gets $3,250; an 8 kW system gets $5,000 (capped).
On a representative 5 kW system in RI: gross cost roughly $14,250 (at default install pricing), federal credit zero, REF grant $3,250, net cost about $11,000, with year-1 electricity savings from full-retail self-consumption plus 80% export crediting, payback near 6.2 years in the calculator's defaults. Path B works for most small residential buyers because the REF money moves the needle hard against a system this size.
VERIFIED 2026-06 · RI Energy tariff (post-April 15 2023); Commerce RI REF program; RIPUCPath A: REG production tariff
This is the second path, and structurally it's a different kind of program. Where Path B credits your offset electricity bill (and gives you upfront cash), Path A buys your electricity from you outright — every kWh you generate, regardless of whether you use it or export it.
The REG mechanics. Rhode Island Energy administers the Renewable Energy Growth (REG) program. PY2026 enrollment pays $0.2723/kWh on all production for 15 years, locked at the rate when you enroll. Self-consumed kWh and exported kWh are paid the same. The contract is administered as a tariff with RI Energy — the payments come from the utility, not as a tax credit.
Key constraints:
- System size limit: 25 kW residential.
- Annual generation cap: 125% of your annual consumption. Oversizing beyond your usage doesn't help — the cap clips your earnings.
- Enrollment opens April 1 for each program year. Capacity is limited and allocated as enrollments come in; popular years close partway through.
- Replaces net metering during the contract. You do not net-meter while enrolled in REG. After 15 years, the system reverts to the standard 80% net metering structure (years 16–25 in the 25-year horizon).
- No REF grant. Path A enrollees cannot take the REF upfront grant. This is the cash you give up to take REG.
- Rate declines yearly for new enrollees. PY2026 = $0.2723; PY2025 was $0.2861; PY2024 was $0.3012. If you're considering REG, the timing of enrollment relative to ceiling decreases matters.
This is NOT how New Jersey SuSI or Minnesota Solar*Rewards work. Both of those are stack incentives — they pay $/kWh on production on top of net metering, so you collect electricity bill savings AND the production payment. REG replaces net metering. The mechanism is fundamentally different, and any quote that adds REG income on top of net metering credit is wrong.
On the same representative 5 kW system: gross cost roughly $14,250, federal credit zero, no REF grant (Path A forfeits it), net cost $14,250, year-1 REG payment about $1,761, total REG payments across years 1–15 around $25,494 (with panel degradation), plus the post-REG net metering tail in years 16–25, payback near 8.1 years. On this size system, Path B's faster cash beats Path A's longer-tail payment — but on bigger systems, that flips.
VERIFIED 2026-06 · RI Energy REG program, PY2026 ceiling $0.2723/kWh; RI OERHow to choose — a heuristic, not a decision
The calculator at the top of this page renders both paths side-by-side for your specific system size. Use that for your real number. As a rule of thumb:
- Small system (under about 6 kW), short horizon, or you care about quick payback: Path B usually wins. The REF grant moves enough upfront cash to beat a 15-year stream of small REG payments.
- Larger system (7–25 kW), or you're planning to hold the system for the full 25 years: Path A usually wins. REG pays for every kWh you generate — both the kWh you use yourself and the kWh you'd otherwise export at 80% retail — so the per-kWh value is high for production-heavy systems.
- Pre-April 15, 2023 system, or Pascoag / Block Island customer: You're on true 1:1 net metering already, and this article's haircut math doesn't apply to you. Path B's net-metering portion is materially better than what we describe; REF grant rules still apply.
There's no single right answer — RI's design forces a real choice based on system size, expected horizon, and cash-flow preference. The calculator handles the per-system math; the structural facts are what this article gives you.
Run your real Rhode Island payback (with the path toggle) →What both paths share
These facts apply regardless of which path you pick.
Retail electricity rate. About $0.29/kWh statewide — among the higher US rates, typical of the New England grid (imported energy, aging transmission). High retail makes self-consumption valuable in Path B and shapes the post-REG tail in Path A.
VERIFIED 2026-06 · eia.govSales tax — EXEMPT. Rhode Island exempts solar equipment from its 7% state sales tax under RI Div. of Taxation Ruling 2018-01. On a typical residential system that's about $1,736 saved at install. Your installed quote should NOT include sales tax — if it does, ask the installer to correct it before signing.
Property tax — EXEMPT for 20 years. Rhode Island exempts the added home value from residential solar from property tax for two decades. No application required.
No state income tax credit. Rhode Island does not offer a state-level solar income tax credit. Its incentive picture is REG (Path A), REF (Path B), net metering, and tax exemptions — not a tax credit on top. Don't budget for one.
Battery in Rhode Island. Rhode Island has an active, unusual battery program: National Grid / RI Energy's ConnectedSolutions pays roughly $225/kW/year to homeowners whose batteries dispatch into summer peak grid events — a performance-based payment, not a flat rebate. On top of that, the REF grant adds a $2,000 battery adder for Path B enrollees (Path A REG enrollees forfeit this along with the rest of REF). Federal credit on the battery purchase is $0 (§25D repealed for storage). The economic case for a Rhode Island battery is genuinely stronger than in most states because of ConnectedSolutions plus the high retail rate (each outage hour avoided is worth more) — but it remains an additional purchase, not a payback-shortener for solar alone.
The federal credit — gone, and the state site is wrong
Worth repeating because RI is unusual on this point. The federal 30% Residential Clean Energy Credit (§25D) was repealed by the One Big Beautiful Bill Act (P.L. 119-21), signed in July 2025. For 2026 purchases, the federal credit is zero for both solar panels and batteries.
The §48E commercial credit (30%) still exists, but only for leased or third-party-owned systems where construction begins before July 4, 2026 — the lessor claims it on your behalf in a PPA, you do not.
The Rhode Island OER (Office of Energy Resources) public page on residential solar has not been updated to reflect the repeal as of mid-2026, and still references the 30% credit as a live incentive. This is unusual — most state energy agencies updated their materials within months of the OBBBA signing. Treat OER's 30% language as outdated, not authoritative. Verify with the IRS or with this calculator, which uses the post-repeal rules.
If a contractor proposal or installer quote includes "30% federal" on a 2026 RI residential purchase, ask them to redo the math with $0 federal. Any reference back to the state OER page as a justification for the 30% number is itself outdated.
VERIFIED 2026-06 · IRS §25D repeal under OBBBA P.L. 119-21The honest picture
| Fact | Path B (default) | Path A (REG) | Source |
|---|---|---|---|
| Federal credit | $0 | $0 | IRS — §25D repealed |
| State income tax credit | None | None | RI OER |
| Net metering — self-consumption | 100% retail (about $0.29) | N/A during contract; standard NM in years 16–25 | RI Energy tariff |
| Export rate | 80% retail (about $0.232) | N/A during contract; 80% in years 16–25 | RI Energy post-April 15, 2023 |
| REF grant | $0.65/W up to $5,000 (+$2,000 battery adder) | Forfeited | Commerce RI REF |
| REG production payment | Not enrolled | $0.2723/kWh × ALL production × 15 yr (locked) | RI Energy REG PY2026 |
| Stacking | Cannot combine with REG | Cannot combine with REF | RI OER program rules |
| Post-15-year status | Continuous | Reverts to standard 80% NM | RI Energy REG |
| System size cap | Net-metering limits apply | 25 kW residential, 125% annual use | RI Energy REG |
| Sales tax | EXEMPT (7%, saves about $1,736) | EXEMPT (same) | RI Div. of Taxation Ruling 2018-01 |
| Property tax | EXEMPT (20 years) | EXEMPT (same) | RI statute |
| Battery (solar paired) | ConnectedSolutions about $225/kW/yr + REF $2,000 adder | ConnectedSolutions; no REF adder | National Grid / RI Energy ConnectedSolutions; Commerce RI REF |
Before you commit:
- Reject any quote that includes a 30% federal credit. Repealed for 2026 purchases. Even RI OER's own page is out of date on this.
- Decide Path A vs Path B explicitly — the two cannot be combined, and the choice is locked at install. Run both numbers in the calculator for your specific system size and horizon before signing.
- Don't budget for REF if you're going REG, and don't budget for REG income if you're going REF — they exclude each other.
- REG enrollment opens April 1 with limited capacity; if you're targeting Path A, time your application.
- Pre-April 15, 2023 systems are grandfathered into true 1:1 net metering — the 80% haircut doesn't apply to you.
- Pascoag or Block Island customers are on different municipal tariffs (true 1:1) — verify locally.
- Don't oversize. Path B's annual surplus settles at avoided cost (about $0.03–0.05); Path A's 125% cap clips earnings beyond your consumption.
- Confirm the sales tax exemption is applied to your installed quote — RI Div. of Taxation Ruling 2018-01, saves about $1,736 on a typical system.
- If you want a battery, check current ConnectedSolutions enrollment and the REF battery adder (Path B only) before committing — the performance-based program pays real annual money.
Estimates only — REG rates change yearly, REF funding is annual and limited, ConnectedSolutions and battery rebates are program-year-dependent. Pre-April 15, 2023 systems and Pascoag/Block Island customers are not modeled. Verify with RI Energy, Rhode Island Commerce, and the RI Office of Energy Resources. This is not financial advice.