Long Island Solar Installation Pros — Calculator
Long Island Solar Payback Calculator
Simple payback estimator for Long Island homes — PSEG Long Island, Freeport Electric, RVC, Greenport. NY 25% credit applied; federal sunset locked in (no 30% baked into 2026 numbers).
How this calculator works
The estimator models annual solar production for a Long Island home using a conservative ~1,100 kWh/kW capacity factor (de-rated by your shade input), values it at the applicable utility rate, applies the New York State 25% credit (capped at $5,000), and divides the net cost by the annual offset to produce a simple payback range.
Federal residential incentives are explicitly NOT applied — the IRS Residential Clean Energy Credit applied to qualified property installed from 2022 through December 31, 2025 and is not available for property placed in service after that date. Rate inflation, financing structures, and battery storage are all NOT modeled. For the full picture, see our payback period resource or request an itemized assessment.
Inputs
Typical LI residential systems run 6–12 kW. From your installer quote, or estimate from your annual usage.
From your installer quote — equipment + labor + soft costs.
Most LI addresses are PSEG Long Island. Freeport, RVC, and Greenport villages have their own municipal utilities with different rate structures.
Simple payback estimate
Simple payback range
8.1–9.8 yrs
From net cost ($22,000 after NY 25% credit) divided by annual offset value ($2,459/yr at PSEG Long Island).
Annual production
9,108 kWh
System × LI capacity × shade
Annual offset value
$2,459
At today's utility rate
NY State credit applied
$5,000
25% capped at $5,000
Net cost after NY credit
$22,000
Cost − NY credit
What this estimate does and does not do
- Uses a conservative LI annual production of ~1,100 kWh/kW (de-rated by your shade input).
- Applies the NY State 25% credit (capped at $5,000).
- Does NOT apply a federal residential credit. The IRS Residential Clean Energy Credit applied to property installed through Dec 31, 2025 and is not available for property placed in service after that date.
- Does NOT model rate inflation — simple payback only.
- Does NOT model financing (cash vs $0-down loan vs lease) — see our lease-vs-buy resource for that math.
Want payback calculated against your real installer quote?
We'll model your specific roof, your last 12 months of PSEG (or municipal utility) usage, your actual quote, and the financing structure — and walk through what payback looks like under cash vs loan vs lease scenarios.
Request a Long Island assessmentCommon questions
What is solar payback period?
Payback period is the number of years until the cumulative bill savings (plus any incentive cash) equal the upfront cost of the system. It is a simple, useful frame for comparing solar to other capital investments. This estimator calculates simple payback — no rate inflation assumption is baked in.
What is a typical solar payback period on Long Island?
For PSEG Long Island customers with full-sun roofs and the NY State 25% credit applied, simple payback typically falls in the 7–12 year range depending on system cost, annual usage, and rate plan. Municipal-utility customers (Freeport Electric, Rockville Centre Electric, Greenport Municipal Light) typically see longer simple payback because the rate is lower than PSEG.
Why does this not include the federal solar tax credit?
The IRS Residential Clean Energy Credit applied to qualified clean energy property installed from 2022 through December 31, 2025 and is not available for property placed in service after that date. We do not bake a 30% federal credit into 2026 payback estimates. Any active federal program at the time of your install is verified during the planning consultation.
Does payback differ between cash, $0-down loan, and lease?
Yes — significantly. This estimator calculates the cash-purchase case. $0-down loans add finance costs that lengthen the effective payback (and 2026 loans should be re-examined for the federal-credit-sunset interaction with the loan reamortization clause). Leases and PPAs shift incentive ownership to the leasing company and produce different payback math. See our lease-vs-buy resource for the full breakdown.
Does this estimator model rate inflation?
No — this is a simple payback calculator. Long Island electric rates have historically risen over time, which would shorten the effective payback. We do not model rate inflation in the estimator because the assumption is the single largest lever in long-payback math, and we prefer to surface that conversation explicitly rather than bake an optimistic assumption into the number.
Want payback calculated against your real installer quote?
We'll model your specific roof, your last 12 months of PSEG (or municipal utility) usage, your actual installer quote, and the financing structure.