Is the 30% federal solar tax credit still available in 2026?

IRS, Residential Clean Energy Credit (page last reviewed or updated 04-Jul-2026): "The credit is not available for any property placed in service after December 31, 2025." (Section 25D was ended for later expenditures by Public Law 119-21 of July 2025.) So the federal 30% credit does not apply to a system installed in 2026; state, utility or local incentives may, type them here That is why the incentive field starts at 0% for the US. Check your state's and your utility's programs and type what applies.

How long does solar take to pay for itself?

Net cost divided by yearly savings, so it depends on the price you pay for electricity and the sun you get. With the starting values: 9.8 years in Texas and 5.9 years in London. A higher electricity price or a cheaper quote shortens it; exporting most of the output at a low rate lengthens it.

What is the 0.5% a year output decline?

NREL, PVWatts Version 5 Manual (NREL/TP-6A20-62641, September 2014), section 11: after light-induced degradation "the module power stabilizes and subsequently follows typical long-term degradation over the lifetime of the installation (~0.5 %/year)". The Trina Vertex data sheet warrants 0.55%/year The table lowers each year's production by that share, so year 25 makes about 89% of year one.

Should I add a price increase per year?

It is a guess about the future, so the field starts at 0 and the table uses today's price for every year. The EIA table shows the US average rose from 17.47 to 18.34 ¢/kWh between June 2025 and June 2026 (about 5%); Ofgem's cap moved from 26.11 to 26.32 p/kWh between the third and fourth quarter of 2026. Type a modest figure such as 2-3% if you want to see the effect, and remember it compounds for 25 years.

What about the electricity I export?

Energy Saving Trust: "Typically, you'll get around 12p for every unit that you don't use yourself through the Smart Export Guarantee." In the US it depends on the utility's net-metering or export tariff. Type the share you expect to export and the rate; both start at 0, which values every kWh at the retail price.

Does the tool include a battery or a loan?

No. A battery adds cost and shifts some exported kWh to self-use; a loan adds interest. Both belong in an installer's quote and in your own spreadsheet. The Pro report exports the cash-flow table to Excel so you can add those lines yourself.

Free calculator

Solar payback and savings calculator

With the US starting values (7 kW at 2.6 $/W installed, no federal credit in 2026, 15.94 ¢/kWh in Texas) the system costs $18,200, saves $1,856 in year one and pays back in 9.8 years. Type your own quote, price and place.

Region and unitsSwitching region reloads that region’s places, prices and units. Somewhere else? Pick “Enter sun hours” and type your own. Your numbers stay in this browser only.

System size (kW)kWThe DC rating. The sizing tool fills it in once you have used it in this browser.Installed cost ($/W)$/WStarting value: EnergySage, "How much do solar panels cost?", read 2026-09-20; edit it.

Incentive, share of the cost (%)%Starting value: IRS, Residential Clean Energy Credit, read 2026-09-20; edit it. The federal 30% credit ended for systems placed in service after 31 December 2025; a state or utility rebate goes here.

StatePeak sun hours per dayhStarting value: Unbound Solar, "Peak Sun Hours by US State", table built from NREL's PVWatts data; "A peak sun hour is one hour of sunlight at an average intensity of 1,000 watts per square meter", read 2026-09-20; edit it.

Electricity price (¢/kWh)¢/kWhTexas: Starting value: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A "Average Price of Electricity to Ultimate Customers by End-Use Sector, by State, June 2026 and 2025", residential column, cents per kilowatthour, June 2026, read 2026-09-20; edit it.Production in year 1 (kWh)kWhFilled from size × sun hours × 365 × (1 − 14% losses) whenever the size or the place changes; type your installer's figure instead if you have one.

Price change per year (%)%0 = today's price for 25 years. A guess about the future, so it starts at 0.Share exported (%)%Production you do not use at home and sell instead. 0 = everything valued at the retail price.Export rate (¢/kWh)¢/kWhWhat your utility pays for exported kWh depends on its net-metering or export tariff; there is no national figure, so the field starts at 0.

Result

Simple payback: 9.8 years
Net savings over 25 years: $25,529
Gross cost: $18,200
Incentive: $0
Net cost: $18,200
Savings in year 1: $1,856
Production in year 1: 11,646 kWh
Paid back in the table by: year 11

Simple payback = net cost / year-1 savings. The table below lowers output by 0.5% a year (NREL) and raises the price by the escalation you typed. No maintenance, inverter replacement, financing or inflation. Estimates from published averages (NREL, EIA, Ofgem, industry cost surveys), each with its source and date: an installer's site survey and shading analysis replace them. Not financial advice.

Year by year

Year	Production	Savings	Cumulative − cost
1	11,646 kWh	$1,856	-$16,344
2	11,588 kWh	$1,847	-$14,497
3	11,530 kWh	$1,838	-$12,659
4	11,472 kWh	$1,829	-$10,830
5	11,415 kWh	$1,820	-$9,010
6	11,358 kWh	$1,810	-$7,200
7	11,301 kWh	$1,801	-$5,399
8	11,244 kWh	$1,792	-$3,606
9	11,188 kWh	$1,783	-$1,823
10	11,132 kWh	$1,774	-$48
11	11,077 kWh	$1,766	$1,717
12	11,021 kWh	$1,757	$3,474
13	10,966 kWh	$1,748	$5,222
14	10,911 kWh	$1,739	$6,961
15	10,857 kWh	$1,731	$8,692
16	10,802 kWh	$1,722	$10,414
17	10,748 kWh	$1,713	$12,127
18	10,695 kWh	$1,705	$13,832
19	10,641 kWh	$1,696	$15,528
20	10,588 kWh	$1,688	$17,216
21	10,535 kWh	$1,679	$18,895
22	10,482 kWh	$1,671	$20,566
23	10,430 kWh	$1,663	$22,228
24	10,378 kWh	$1,654	$23,883
25	10,326 kWh	$1,646	$25,529

Want it on paper? Pro prints the sizing report.

Inputs, system size, panels and roof area, production by month, cost, payback and the 25-year cash flow, with every source. Print, save as PDF or export to Excel.

See Pro

How it works

Gross cost = system kW × 1,000 × cost per watt (typed per kWp in the UK). Net cost = gross cost − incentive. Savings in year one = production × electricity price, or, if you export a share, the used share at the retail price plus the exported share at the export rate. Simple payback = net cost / year-one savings. The table then runs 25 years: production falls by 0.5% a year (NREL), the price rises by the escalation you type (0 by default), and the last column is cumulative savings minus the net cost.

With the US starting values: 7 kW × 1,000 × $2.60 per W = $18,200; production 11,646 kWh × 15.94 ¢/kWh = $1,856 a year; $18,200 / $1,856 = 9.8 years. Over 25 years the savings come to $43,727, $25,527 net of the cost. In the UK, a 4.5 kW system at £1,690 per kWp (derived from the Energy Saving Trust's "around £7,600" for a typical 4.5 kWp system, August 2026) costs £7,605; at the Ofgem cap of 26.32 p/kWh in London it saves £1,294 a year if every kWh replaces bought electricity, a payback of 5.9 years. The Energy Saving Trust's own payback for London is 9 years with export payments and a home occupied all day.

The cost per watt is a national survey average, not a quote: get three quotes and type the real figure. The electricity price is the state or country average from the regulator; your tariff replaces it. The federal residential credit (25D) ended for systems placed in service after 31 December 2025, so the US incentive starts at 0%; state or utility rebates go in that field. Not included: loan interest, maintenance, an inverter replacement around year 10-15, insurance, or the time-of-day pattern of your use.

Sources of the US starting values

Peak sun hours by US state: Unbound Solar, "Peak Sun Hours by US State" (undated, read 2026-09-20), table built from NREL's PVWatts data (National Solar Radiation Database); "A peak sun hour is one hour of sunlight at an average intensity of 1,000 watts per square meter (1 kW/m²)" — https://unboundsolar.com/solar-information/sun-hours-us-map, read on 2026-09-20
Panel wattage and area: Trina Solar, Vertex TSM-DE09 data sheet (version TSM_EN_2020_PA3), product range 390-405 W: module dimensions "1754×1096×30 mm (69.06×43.15×1.18 inches)", 21.0 kg, efficiency up to 21.1%, "25 year Power Warranty, 0.55% Annual Power Attenuation, 2% first year degradation". Area = 1.754 m × 1.096 m = 1.922 m² per panel — https://static.trinasolar.com/sites/default/files/EN_Datasheet_Vertex_DE09.pdf, read on 2026-09-20
System losses: NREL, PVWatts Version 5 Manual (NREL/TP-6A20-62641, September 2014), section 11 System Losses, Table 6: soiling 2%, shading 3%, snow 0%, mismatch 2%, wiring 2%, connections 0.5%, light-induced degradation 1.5%, nameplate rating 1%, age 0%, availability 3%; "The default total system loss is calculated to be 14 %" (the losses multiply, they do not add) — https://www.nrel.gov/docs/fy14osti/62641.pdf, read on 2026-09-20
Installed cost: EnergySage, "How much do solar panels cost?" (updated Jun 30, 2026): "systems average about $2.60 per watt before incentives"; a 12 kW system "costs an average of $31,135 before incentives". SolarReviews (published September 2026) puts the average at $3.03 per watt — https://www.energysage.com/local-data/solar-panel-cost/ and https://www.solarreviews.com/solar-panel-cost, read on 2026-09-20
Incentive: IRS, Residential Clean Energy Credit (page last reviewed or updated 04-Jul-2026): "The credit is not available for any property placed in service after December 31, 2025." (Section 25D was ended for later expenditures by Public Law 119-21 of July 2025.) So the federal 30% credit does not apply to a system installed in 2026; state, utility or local incentives may, type them here — https://www.irs.gov/credits-deductions/residential-clean-energy-credit, read on 2026-09-20
Electricity price: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A "Average Price of Electricity to Ultimate Customers by End-Use Sector, by State, June 2026 and 2025", residential column, cents per kilowatthour, June 2026 — https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_a: U.S. total 18.34 cents per kilowatthour (June 2025: 17.47). Picking a state fills in that state's figure from the same table, read on 2026-09-20
Export rate: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A "Average Price of Electricity to Ultimate Customers by End-Use Sector, by State, June 2026 and 2025", residential column, cents per kilowatthour, June 2026 — https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_a (the table has no export rates), read on 2026-09-20
Output decline per year: NREL, PVWatts Version 5 Manual (NREL/TP-6A20-62641, September 2014), section 11: after light-induced degradation "the module power stabilizes and subsequently follows typical long-term degradation over the lifetime of the installation (~0.5 %/year)". The Trina Vertex data sheet warrants 0.55%/year — https://www.nrel.gov/docs/fy14osti/62641.pdf, read on 2026-09-20

UK starting values (Energy Saving Trust, Ofgem, HMRC, PVGIS) are shown under each field when you switch region.

Estimates from published averages (NREL, EIA, Ofgem, industry cost surveys), each with its source and date: an installer's site survey and shading analysis replace them. Not financial advice.

Frequently asked questions

Is the 30% federal solar tax credit still available in 2026?: IRS, Residential Clean Energy Credit (page last reviewed or updated 04-Jul-2026): "The credit is not available for any property placed in service after December 31, 2025." (Section 25D was ended for later expenditures by Public Law 119-21 of July 2025.) So the federal 30% credit does not apply to a system installed in 2026; state, utility or local incentives may, type them here That is why the incentive field starts at 0% for the US. Check your state's and your utility's programs and type what applies.
How long does solar take to pay for itself?: Net cost divided by yearly savings, so it depends on the price you pay for electricity and the sun you get. With the starting values: 9.8 years in Texas and 5.9 years in London. A higher electricity price or a cheaper quote shortens it; exporting most of the output at a low rate lengthens it.
What is the 0.5% a year output decline?: NREL, PVWatts Version 5 Manual (NREL/TP-6A20-62641, September 2014), section 11: after light-induced degradation "the module power stabilizes and subsequently follows typical long-term degradation over the lifetime of the installation (~0.5 %/year)". The Trina Vertex data sheet warrants 0.55%/year The table lowers each year's production by that share, so year 25 makes about 89% of year one.
Should I add a price increase per year?: It is a guess about the future, so the field starts at 0 and the table uses today's price for every year. The EIA table shows the US average rose from 17.47 to 18.34 ¢/kWh between June 2025 and June 2026 (about 5%); Ofgem's cap moved from 26.11 to 26.32 p/kWh between the third and fourth quarter of 2026. Type a modest figure such as 2-3% if you want to see the effect, and remember it compounds for 25 years.
What about the electricity I export?: Energy Saving Trust: "Typically, you'll get around 12p for every unit that you don't use yourself through the Smart Export Guarantee." In the US it depends on the utility's net-metering or export tariff. Type the share you expect to export and the rate; both start at 0, which values every kWh at the retail price.
Does the tool include a battery or a loan?: No. A battery adds cost and shifts some exported kWh to self-use; a loan adds interest. Both belong in an installer's quote and in your own spreadsheet. The Pro report exports the cash-flow table to Excel so you can add those lines yourself.

Guides

How much do solar panels cost in the UK in 2026?
Around £7,600 for a typical 4.5 kWp system (Energy Saving Trust, 2026), £1,690 per kWp; 6 to 16 panels, savings at the Ofgem cap, payback by UK city.
How much do solar panels cost in Texas in 2026?
Installed cost for 4 to 15 kW at the EnergySage $ per watt, Texas output and savings at the EIA price, a 7 kW system in every state and the 25-year table.
How much do solar panels cost for a 2,000 square foot house?
About $22,880 before incentives: 22 panels of 400 W (8.8 kW) cover the 12,173 kWh a year an average 2,000-2,499 sq ft home uses (EIA), at 4.5 sun hours.