Solar energy installation costs in 2026: price per watt, by system size, by state
Last reviewed · all figures assume no federal credit
Installed solar runs about $3.00 per watt in 2026, so a typical 7 kW system costs roughly $21,000 — and there is no federal tax credit left to subtract, because the 30% Residential Clean Energy Credit ended for systems completed after December 31, 2025. Every number below is derived from the same model the payback calculator uses.
The formula behind every quote
Installation cost is almost boringly linear: cost = system size in watts × installed price per watt. What varies is the two inputs. Size comes from your usage and your state's sunshine — the same house needs a smaller array in Arizona than in Michigan. Price per watt moves with roof complexity, hardware tier and, most of all, how many installers you let compete. That is the entire arithmetic; a quote that resists being broken down into those two numbers is hiding something in one of them.
Cost by system size
A modern panel is roughly 375–410 W, so panel counts scale with the array. Sizes below bracket most single-family homes:
| System size | Approx. panels | Installed cost | Per watt |
|---|---|---|---|
| 4 kW | 10–11 panels | $12,000 | $3.00/W |
| 5 kW | 12–13 panels | $15,000 | $3.00/W |
| 6 kW | 15–16 panels | $18,000 | $3.00/W |
| 7 kW | 17–19 panels | $21,000 | $3.00/W |
| 8 kW | 20–21 panels | $24,000 | $3.00/W |
| 10 kW | 24–27 panels | $30,000 | $3.00/W |
| 12 kW | 29–32 panels | $36,000 | $3.00/W |
Two honest caveats. Small systems often price above the per-watt average because fixed costs — permitting, mobilisation, design — have nowhere to spread. And a battery, if you add one, is priced on energy capacity (kilowatt-hours), not watts, so it does not belong in this table at all.
What moves the price up or down
Up: steep or multi-plane roofs, second-story work, premium module tiers, trenching to a detached structure, rapid-shutdown hardware on small arrays, and low-competition rural markets where the nearest bidder is two hours away.
Down: simple single-plane roofs, standard-tier modules from a healthy brand, utilities with straightforward interconnection, and — more than any hardware choice — getting three or more competing bids. Quote dispersion for the same roof routinely exceeds any brand premium.
Cost and payback by state
The same physical system earns different money in different states, because electricity rates and sun hours differ. The table sizes a system to a representative $150-a-month bill in each state and shows what it would cost installed, sorted from fastest to slowest payback:
| State | $ / kWh | Sun hrs | System | Installed cost | Payback |
|---|---|---|---|---|---|
| Hawaii | $0.41 | 5.8 | 2.6 kW | $7,777 | 4.3 yrs |
| California | $0.31 | 5.5 | 3.6 kW | $10,846 | 6.0 yrs |
| Massachusetts | $0.30 | 4.0 | 5.1 kW | $15,411 | 8.6 yrs |
| Connecticut | $0.28 | 4.0 | 5.5 kW | $16,512 | 9.2 yrs |
| Arizona | $0.15 | 6.5 | 6.3 kW | $18,967 | 10.5 yrs |
| New Mexico | $0.15 | 6.5 | 6.3 kW | $18,967 | 10.5 yrs |
| Nevada | $0.15 | 6.4 | 6.4 kW | $19,264 | 10.7 yrs |
| Maine | $0.23 | 4.0 | 6.7 kW | $20,101 | 11.2 yrs |
| New York | $0.23 | 3.8 | 7.1 kW | $21,159 | 11.8 yrs |
| Colorado | $0.15 | 5.5 | 7.5 kW | $22,416 | 12.5 yrs |
| Florida | $0.15 | 5.3 | 7.8 kW | $23,262 | 12.9 yrs |
| Texas | $0.15 | 5.2 | 7.9 kW | $23,709 | 13.2 yrs |
| Maryland | $0.18 | 4.2 | 8.2 kW | $24,462 | 13.6 yrs |
| New Jersey | $0.18 | 4.2 | 8.2 kW | $24,462 | 13.6 yrs |
| Michigan | $0.19 | 3.8 | 8.5 kW | $25,614 | 14.2 yrs |
| South Carolina | $0.15 | 4.7 | 8.7 kW | $26,231 | 14.6 yrs |
| Pennsylvania | $0.18 | 3.9 | 8.8 kW | $26,344 | 14.6 yrs |
| Washington DC | $0.16 | 4.2 | 9.2 kW | $27,520 | 15.3 yrs |
| Georgia | $0.14 | 4.7 | 9.4 kW | $28,105 | 15.6 yrs |
| Illinois | $0.16 | 4.0 | 9.6 kW | $28,896 | 16.1 yrs |
| Ohio | $0.16 | 3.9 | 9.9 kW | $29,636 | 16.5 yrs |
| Virginia | $0.14 | 4.4 | 10.0 kW | $30,021 | 16.7 yrs |
| North Carolina | $0.13 | 4.7 | 10.1 kW | $30,267 | 16.8 yrs |
| Washington | $0.11 | 3.5 | 16.0 kW | $48,034 | 26.7 yrs |
Read the extremes together: in Hawaii the combination of high rates and good sun pays a system back in about 4.3 years even with no federal credit, while in Washington the same bill needs roughly 26.7 years. Every state's full breakdown — incentives, utilities, net-metering posture — is on its state page.
What the end of the federal credit did to these prices
Nothing to the sticker price — and everything to the net price. Installed costs per watt did not jump when §25D ended; what disappeared is the 30% cheque that used to follow. A system that netted $14,700 in 2025 nets the full $21,000 in 2026. The details, including the completed-installation rule that catches systems paid for in 2025 but switched on later, are in the federal credit explainer.
A checklist for comparing quotes
- Installed cost per watt — total contract price ÷ system watts. Ask every bidder for this one number and make them defend it.
- System size against your usage — a bid sized to your roof's revenue rather than your bill is a red flag. Size it yourself first with the calculator.
- What tier of module and inverter — mid-tier hardware from a bankable brand is usually the value pick; premium tiers must justify themselves in production, not in brochure pages.
- Incentives claimed — the 30% federal credit ended for systems completed after December 31, 2025, so any bid still showing one was written before the law changed. State and utility incentives are real; verify them against your state page.
- Production estimate — compare promised annual kilowatt-hours across bids at the same tariff, not nameplate watts.
Price your own system
The homepage payback calculator turns your power bill and state into system size, installed cost, payback years and 25-year net — the same model this page's tables come from, with your numbers instead of a representative ones. No phone number, no salesperson, no signup.
Questions people ask
How much does solar cost to install in 2026?
About $3.00 per watt installed, so the total tracks system size: roughly $36,000 for a 12 kW array down to about $12,000 for a 4 kW one. The size you actually need comes from your usage and your state's sun, not from a sales pitch — the calculator on the homepage sizes it from your power bill.
What is a good price per watt for solar panels?
Treat $3.00/W as the midpoint of a normal range — roughly $2.50 to $3.50 per watt fully installed in most of the country. Below that, check what has been quietly dropped (permitting, monitoring, inverter tier); above it, you are usually paying a premium brand or a hard roof. Always compare quotes on installed cost per watt, never on monthly payment.
Do these prices include the federal tax credit?
No — and none should. The 30% federal Residential Clean Energy Credit ended for systems whose installation was completed after December 31, 2025, so a system finished today has no federal credit to subtract. Any quote that still shows one is out of date. State and utility incentives still exist and vary widely; they are listed on each state page.
How do I estimate the installation cost for my house?
Take your monthly power bill, divide by your state's rate to get annual kilowatt-hours, divide again by your state's peak-sun-hours × 0.8 to get system size in kilowatts, and multiply by $3000 per kilowatt. Or skip the arithmetic: the homepage calculator does all four steps from your bill and state, with no signup.
Cost model: $3.00/W installed, performance ratio 0.8, representative bill $150/month — the same constants as the methodology page, last reviewed by SolarDime editorial. Estimates for guidance only; real quotes depend on your roof, shading, utility and installer.
Data sources and assumptions
- Electricity ratesU.S. EIA · 2026 state averages
- Solar resourceNREL · 2026 state averages
- Federal tax treatmentIRS · Credit ended for installations completed after 31 Dec 2025 (P.L. 119-21)
- Installed costInstalled cost per watt · 2026 estimate, user-editable
State assumptions last reviewed: . Rules can change; verify your utility and state program before signing a contract. Full methodology.