Solar Panel Calculator

Solar payback by state in 2026

Payback depends on two things that change from state to state: what electricity costs and how much sun the panels get. Under net metering it does not depend on the size of the system, because cost and savings both scale with size. That makes it possible to compare every state on the same footing.

The table below uses the calculator’s defaults for each state: the January–July 2026 EIA residential price, PVWatts output for a reference city, the $4.0/W median installed price, prices rising 2.79% a year, output falling 0.5% a year, cash purchase, net metering, no rebates. The range column shows payback at $3.0/W and $5.2/W. The last column is what each kW of panels saves over 25 years after paying for itself.

Two patterns stand out. First, price beats sunshine. Massachusetts gets about a quarter less sun than Arizona but pays back faster, because its electricity costs almost twice as much. Second, the sunniest states with cheap power (Nevada, Utah, New Mexico) land in the middle of the table, not at the top.

What solar panels cost in 2026

The most reliable public figure for what US homeowners pay is Lawrence Berkeley National Laboratory’s annual Tracking the Sun study, built from project-level records for roughly 4.9 million systems. Its 2025 Data Update (October 2025) covers systems installed in 2024. These are gross prices before any incentive, for homeowner-owned systems without batteries, in 2024 dollars.

The median home system installed in 2024 was 7.2 kW, which is why the table prices a 7 kW system. Three findings from the same report matter for buyers:

• Loans cost more up front. Loan-financed systems had a median price $1.2 per watt higher than cash purchases in 2024, partly because dealer fees are rolled into the price. That gap was $0.6 per watt in 2017.
• The most common price is below the median. For cash purchases, the most frequent price was under $3 per watt. A few very expensive systems pull the median up.
• Installers differ widely. Among the 100 largest residential installers, roughly half had a median price below $4 per watt, only a handful were below $3, and almost one in five were above $5.

Prices were broadly flat from 2023 to 2024 after inflation. The calculator uses these 2024 figures as published and does not inflate them, so treat them as a reference point and replace them with the price on your quote.

The federal solar tax credit has ended

From 2022 to 2025, homeowners could claim 30% of the cost of a solar system as a federal tax credit under section 25D of the tax code. The law signed on 4 July 2025 (Public Law 119-21) ended that credit early. The IRS guidance sets out two rules that matter:

• No credit is allowed for expenditures made after 31 December 2025.
• An expenditure counts as made when installation is completed, not when you pay. A system paid for in 2025 but finished in 2026 gets no credit.

Unused 25D credit from an earlier year can still be carried forward on your tax return. That only helps people who installed in 2025 or before.

Leases and power purchase agreements, where a company owns the panels on your roof, fall under different, business-side tax rules. This calculator models only a system you buy outright. State and utility rebates still exist in some places; enter them under More options.

How the calculator works

The 2.79% growth rate is the actual compound growth of the US average residential price from 12.52¢ in 2014 to 16.48¢ in 2024 (EIA Electric Power Annual, Table 2.4). It is history, not a forecast. It includes the 2021–2023 jump; from 2014 to 2020 alone prices grew only 0.82% a year. If you expect slower increases, lower it under More options. Payback gets longer.

The 25-year horizon matches the length of a typical panel performance warranty. Panels often keep producing after that, so the 25-year saving is conservative on that side.

Worked example: a Texas home with a $150 bill

This is the example the calculator loads with. All inputs are the defaults for Texas.

The same house in Los Angeles pays back in 6.7 years: electricity costs more than twice as much (33.25¢) and the panels make 18% more power. In Seattle it takes 20.4 years: cheaper power and much less sun.

Net metering and reduced export rates

Solar panels make most of their power in the middle of the day, when many households use little. The surplus goes to the grid. What your utility pays for it decides a large part of your savings.

• Net metering credits each exported kWh at the full retail price, as if your meter ran backwards. The calculator assumes this by default.
• Reduced export credit pays a lower rate for exports. California’s Net Billing Tariff, which replaced net metering for new customers in April 2023, is the best-known example, and other utilities have followed.

To model a reduced rate, choose Reduced export rate under More options, enter what your utility pays per exported kWh, and set the share of solar you use yourself as it is produced. The default 40% is a GreenCalculus assumption for a home without a battery. It varies with when you use power. For the California example at a 5¢ export rate and 40% self-use, payback rises from 6.7 to 13.1 years. That one setting can double payback, so check your utility’s current tariff before you trust any result. Where exports earn little, a battery can store midday solar for the evening; the home battery cost calculator shows what one costs and the rate gap it needs to pay back.

What changes your payback the most

Ranked by how far they move the result for a typical home:

1. How exports are paid. Net metering versus a low export rate can double payback.
2. Your installed price. Moving from $4.0 to $3.0 per watt cuts payback by about a quarter in every state; $5.2 adds about the same.
3. Your electricity price. It is the multiplier on every kWh. Use the rate from your bill, including delivery charges that scale with use.
4. Solar output. A shaded or east-west roof can produce noticeably less than the PVWatts reference figure. Your installer’s production estimate for your roof is better than a state average.
5. Price growth. Lower growth stretches payback, higher growth shortens it.

System size barely matters to payback under net metering. It matters a great deal under a reduced export rate, because a bigger system exports a larger share of its output at the lower rate.

Measure your use before you size solar

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The calculator sizes a system from your yearly use, so a real figure beats an estimate. Twelve months of bills give you the total; a whole-home monitor shows when your home uses power and which circuits use the most, which also helps you judge how much solar output you would use yourself rather than export. These are widely sold products, as listed on Amazon in October 2026; specifications are the makers’ own.

A monitor in the panel should be fitted by an electrician if you are not comfortable working there.

How to check an installer’s quote

Because price is the biggest lever you control, it pays to compare quotes. Berkeley Lab found that the median price charged by the largest installers ranged from under $3 to over $5 per watt.

• Work out the price per watt. Divide the total price by the system size in watts (DC). Compare it with the $3.0–5.2 range above.
• Ask for the production estimate. A good quote states expected annual kWh for your roof. Enter it as Solar output (kWh ÷ system kW).
• Separate the loan from the system. If financing is offered, ask for the cash price too. The difference is the cost of the loan.
• Check the tax credit line. A 2026 quote should not include the federal 25D credit for a system you will own.
• Confirm the export terms. Ask which tariff your utility will put you on and what it pays for exports.

Then put the quote’s size, price and production into the calculator and compare the payback with your state’s line in the table.

The carbon side

Every kWh your panels produce is a kWh the grid does not have to generate. The calculator values that using your state’s grid emission factor from EPA eGRID. The Texas example avoids about 3.9 tonnes of CO₂ a year. The benefit is largest where the grid burns the most coal and gas: each kW of panels avoids about 1.3 tonnes a year in Wyoming and about 0.13 tonnes in Washington, whose grid is mostly hydropower.

For how solar compares with a heat pump and other home changes, see how to reduce the carbon footprint of your home.

Solar panels also take carbon to make. The calculator shows how long the panels take to repay it on your state’s grid; in Texas it is under three years. For the full carbon accounting, including panel origin and a decarbonising grid, use the solar carbon payback calculator, and for what goes into a panel see the carbon footprint of a solar panel.

Weighing your heating too? The heat pump installation cost calculator compares a heat pump’s running cost with gas, propane or oil in every state.

Data sources and updates

Every figure is stored in the GreenCalculus MasterBrain with its exact source cell, and the calculator reads the live values; the version is shown under each result. Electricity prices are refreshed when EIA publishes new monthly data, and installed prices when Berkeley Lab releases its next annual update. You can see every factor the result used under View calculation detail and export them as JSON or CSV.

Frequently asked questions

Methodology notes and limitations

State averages, not your tariff. EIA’s figure is average revenue per kWh across all residential customers in the state, including fixed charges spread over usage. Your own rate, time-of-use plan and fixed charges will differ. The January–July average covers only part of the year, so it can differ from a full-year figure.

One reference city per state. PVWatts output is for a single location in each state (listed in the table) with a standard south-facing, 20° roof system. Large states such as California and Texas vary a lot inside their borders, and a real roof’s direction, tilt and shading change output.

Installed prices are 2024 medians. They are in 2024 dollars and are not adjusted to 2026. Battery-paired systems cost more per watt and are not included.

Cash purchase, undiscounted. The 25-year savings are a simple sum, without a discount rate, financing cost, inverter replacement, maintenance, insurance or property-tax effects. Including those would lengthen payback somewhat.

Not financial or tax advice. Use the result to judge a quote, then confirm the numbers with your installer, your utility’s tariff and a tax professional.