How long does it take for solar panels to pay for themselves?

Payback depends on three numbers you can look up: your installer's quote, the PVWatts production for your address and the rate on your bill. On this page's presets, payback runs from 6.3 years (the High Electricity Rate preset, 7 kW in Massachusetts at a 30-cent scenario rate) to 14.6 years (the Low Sun Region preset, 6 kW in Oregon at a 14-cent scenario rate); the Average Home preset at the EIA average rate takes 10.2 years. After payback, the savings for the rest of the calculator's 25-year horizon are net gain.

Does the federal solar tax credit apply to battery storage?

Not any more. The federal residential credit that covered battery storage (Section 25D) ended for expenditures after December 31, 2025 under Public Law 119-21, so batteries installed from 2026 onward earn no federal credit. Systems completed by the 2025 deadline could claim 30%, including batteries charged primarily from the solar array. Some states still run their own storage incentives. Check the DSIRE database before assuming a credit applies.

How does electricity rate inflation affect solar ROI?

Rising electricity rates improve solar returns over time because each kWh your system makes offsets a rate that keeps climbing. EIA's residential average rose from 12.52 to 16.48 cents per kWh between 2014 and 2024, a compound 2.8% a year (the calculator's default); at that rate 17.23 cents per kWh becomes about 33 cents per kWh by year 25. While the rate rises faster than the panels degrade, each year saves more than the year before. At the page defaults the 25-year net savings are $30,945 with the 2.8% increase against $17,258 with none, about 1.79 times as much.

Is solar still worth it if my electricity rate is low?

Solar can still pay back at low rates, but the payback stretches. The Low Sun Region preset (6 kW in Oregon at 45.49 N, 122.70 W, 6,709 kWh/yr from PVWatts, $16,080, a 14-cent scenario rate) takes 14.6 years, against 10.2 years for the same size in North Carolina at 17.23 cents: still inside the 25-year horizon, but less compelling than high-rate areas. The math improves if your utility is raising rates aggressively, if you have strong state incentives, or if your primary motivation includes energy independence and backup power. Run the numbers with your actual rate and projected increases before deciding. Our electricity costs guide explains how to read your utility bill and find your true marginal rate.

Solar ROI Calculator - Payback Period

8 min read

Solar panels are a long-term financial commitment, not just an environmental one. This solar ROI calculator shows you the real numbers: how many years until your system pays for itself, what you save over 25 years, and how rising electricity prices tilt the math further in your favour. Plug in your actual quotes and utility rate to get a personalised answer instead of relying on industry averages.

Solar ROI figures showing a 10.2-year payback, a $16,080 system cost and $1,415 first-year savings.

Steps to Evaluate Solar as an Investment

Get at least three installer quotes. Prices vary 20-40% between installers in the same city. Each quote should itemise equipment, labour, permitting, and interconnection fees. NLR's Q1 2023 benchmark for a residential system is $2.68 per watt DC (NREL/TP-7A40-87303, in 2022 dollars), so a 6kW system comes to $16,080 before credits; the benchmark leaves out optional items such as additional electrical or roofing work, which a quote may include.
Look up your actual electricity rate. Your utility bill shows the rate per kWh (not the total bill divided by usage, which includes fixed charges). The rate that matters is the marginal rate: the price of the last kWh you consume. Some utilities have tiered rates where solar offsets the most expensive tier first, making the payback faster than average-rate calculations suggest.
Calculate your net cost after incentives. The federal residential credit (IRC Section 25D) ended for installations completed after December 31, 2025 under Public Law 119-21, so for most buyers today the installed price is the net federal cost: for example, an $18,000 quote stays $18,000. State incentives and utility rebates are now the main levers, and they still apply in many states; check the DSIRE database for yours.
Compare 25-year savings to your net cost. At the defaults, a 6kW system makes 8,214 kWh in its first year (PVWatts for North Carolina), valued at 17.23 cents per kWh rising 2.8% a year with 0.5% annual degradation; that electricity is worth about $47,000 over 25 years against the $16,080 default cost: a 10.2-year payback and $30,945 net. Enter your own quote, PVWatts figure and rate for your result. Our solar panel output calculator gives a quick panel-level estimate; on this page, the PVWatts figure for your address is the one to enter.

Cumulative savings curve for a 6kW system crossing the $16,080 cost at 10.2 years, the payback at the defaults. — At this page's defaults a 6kW residential system pays for itself in 10.2 years, then generates net savings for the remaining 14.8 years of the 25-year horizon.

How the Federal Solar Tax Credit Works

The federal residential clean energy credit (IRC Section 25D) is no longer available for new installations: Public Law 119-21 (July 4, 2025) ended it for expenditures after December 31, 2025, and the IRS treats an installation completed after that date as made after it. While it applied, from 2022 through the end of 2025, it returned 30% of system cost as a dollar-for-dollar federal credit, which is why 30% figures still circulate in older guides and installer marketing.

Buyers whose installations were completed by the December 31, 2025 deadline claim the credit on their 2025 return; it covered panels, inverters, racking, wiring, labour, battery storage, and certain roof work. For installations from 2026 onward there is currently no federal residential credit: run the calculator above with 0% federal, or with your state credit percentage where one exists.

State incentives are now the main game. States and utilities run their own incentive and net-metering programmes, and they differ from state to state; your state's own programme page is the source for yours. Check the DSIRE database for current incentives in your state.

Preset Payback Periods and Assumptions

Preset	System	PVWatts point	Annual production	Cost at $2.68/W	Rate	Rate increase	Payback
Small Home	4 kW	35.81 N, 78.62 W (North Carolina)	5,476 kWh/yr	$10,720	17.23 cents	2.8%	10.2 years
Average Home	6 kW	35.81 N, 78.62 W (North Carolina)	8,214 kWh/yr	$16,080	17.23 cents	2.8%	10.2 years
Large Home	10 kW	35.81 N, 78.62 W (North Carolina)	13,689 kWh/yr	$26,800	17.23 cents	2.8%	10.2 years
Low Sun Region	6 kW	45.49 N, 122.70 W (Oregon)	6,709 kWh/yr	$16,080	14 cents (scenario)	2.8%	14.6 years
High Electricity Rate	7 kW	42.37 N, 71.06 W (Massachusetts)	9,113 kWh/yr	$18,760	30 cents (scenario)	4% (scenario)	6.3 years

Every preset's production is a PVWatts v8 run (the NLR model, 14 % system losses, tilt 20, azimuth 180) at the point shown, and every cost is the system size times NLR's $2.68 per W DC benchmark. The 17.23-cent rate is the page default, the 2025 U.S. residential average (EIA-861). The 14-cent and 30-cent rates and the 4% rate increase are scenario assumptions, not state averages. Your own PVWatts run, quote and bill replace all of them.

Assumptions. The calculator runs for 25 years, the length of the 25 Year power warranty Trina prints on its TSM-DE09.05 datasheet. It values every kWh the system makes at your retail rate, which assumes net metering credits your exports at that rate; your utility's net-metering tariff is the source for what exports actually earn. It does not discount future savings and does not include inverter replacement or maintenance.

On these presets the rate does more than the sunshine: the Massachusetts preset makes less per kW than the North Carolina ones (9,113 / 7 = 1,302 kWh against 8,214 / 6 = 1,369 kWh) yet pays back fastest. Use our solar panel and battery sizing calculator to determine whether adding storage improves your economics under time-of-use billing.

Worked Examples

Average American Home Going Solar

Context

A homeowner in North Carolina installs a 6kW solar system for $18,000. Their electricity rate is $0.16/kWh (a scenario rate for this example), PVWatts gives 8,214 kWh/yr for 6 kW DC at 35.81 N, 78.62 W (14 % losses, tilt 20, azimuth 180), and they expect 3% annual rate increases. Panel degradation is 0.5% per year. With the federal residential credit (Section 25D) ended for installations completed after December 31, 2025, no federal credit applies.

Calculation

Net cost = $18,000 (no federal credit applies)

Year 1 production = 8,214 kWh (the PVWatts AC Energy figure for this system and place)

Year 1 savings = 8,214 × $0.16 = $1,314

Year y savings = 8,214 × 0.995^(y - 1) × $0.16 × 1.03^(y - 1)

Cumulative savings pass $18,000 in year 12: payback 11.9 years

Interpretation

The system pays for itself in about 11.9 years. Over 25 years, cumulative savings reach about $44,800 depending on actual rate increases: about $26,800 net of the system cost, a 149% return on investment. Use the solar panel size calculator to confirm the array wattage matches your roof space and daily consumption.

Takeaway

An 11.9-year payback inside the 25-year horizon leaves about 13 years of net savings, but the arithmetic is leaner than before: when the 30% federal credit applied (installations completed by December 31, 2025), this same system paid back in about 8.7 years. State and utility incentives are now the main levers for shortening payback.

High-Rate State Investment

Context

A homeowner in Massachusetts installs an 8kW system for $24,000. Their electricity rate is $0.28/kWh (a scenario rate for this example, among the highest in the US), PVWatts gives 10,415 kWh/yr for 8 kW DC at 42.37 N, 71.06 W (14 % losses, tilt 20, azimuth 180), and they expect 4% annual rate increases due to regional grid costs. Panel degradation is 0.5% per year. No federal credit applies (Section 25D ended December 31, 2025).

Calculation

Net cost = $24,000 (no federal credit applies)

Year 1 production = 10,415 kWh (the PVWatts AC Energy figure for this system and place)

Year 1 savings = 10,415 × $0.28 = $2,916

Year y savings = 10,415 × 0.995^(y - 1) × $0.28 × 1.04^(y - 1)

Cumulative savings pass $24,000 in year 8: payback 7.4 years

Interpretation

Despite making less per kW than the North Carolina example, the high electricity rate drives a 7.4-year payback. Over 25 years, this system generates about $113,300 in cumulative savings (about $89,300 net of cost) at 4% annual rate increases. The cost per kWh calculator prices a device's use at the rate you enter, such as your blended rate if you have tiered pricing.

Takeaway

High electricity rates outweigh sunshine for ROI. Per kW this system makes 10,415 / 8 = 1,302 kWh a year against 8,214 / 6 = 1,369 kWh in the North Carolina example, about 5% less, yet each kWh is worth $0.28 against $0.16, 1.75 times as much, so it pays back in 7.4 years against 11.9.

Frequently Asked Questions

Glossary

Payback Period

The number of years it takes for cumulative electricity savings to equal the net cost of a solar installation. After payback, every kWh produced is effectively free. On this page's presets payback runs from 6.3 to 14.6 years, depending on the quote, the production and the electricity rate.

Net Metering

A billing arrangement where excess solar electricity sent to the grid earns credits on your utility bill, typically at the full retail rate. Net metering effectively turns the grid into a free battery: you export surplus during the day and draw credited power at night. Policies vary widely by state and utility.

Panel Degradation Rate

The annual percentage decrease in a solar panel's electricity output as it ages. The median of nearly 2,000 reported rates is 0.5% per year (Jordan and Kurtz, NLR); at that rate a panel rated at 400W produces about 380W after 10 years and 353W after 25 years. Makers print their own warranty terms: Trina's Vertex S datasheet prints 2% first-year degradation, 0.55% annual degradation from year 2 to 25 and 84.8% of rated output at year 25 on its warranty chart; Sungrow's module datasheet prints first-year power degradation under 1%, under 0.4% a year from year 2 to 30, and 87.4% on its 30-year warranty chart. This calculator takes year one as the production figure you enter and applies the yearly rate from year two on, with no separate first-year drop. The first-year light-induced loss is in the PVWatts figure instead: PVWatts' default 14% system losses include 1.5% for light-induced degradation in the first few months of operation, and Jordan and Kurtz's long-term rates leave short-term light-induced degradation out.

Not sure how many panels fit on your roof? Our solar power roof area calculator tells you the maximum array size for your available space.

Solar ROI depends on three things you can look up in 10 minutes: your electricity rate, the PVWatts production for your address, and the installed cost from a local quote. Plug those real numbers in above. Generic industry averages hide whether solar makes sense for your specific house. With the federal 30% credit gone (Section 25D ended for installations completed after December 31, 2025), your electricity rate and any state incentives are the biggest levers. Households charging an EV from a rooftop array see some of the cheapest per-mile driving costs in the US. Our walkthrough of the four levers that drive EV charging cost shows how solar+EV ranks against the other driver profiles. Our solar payback period guide walks through the full calculation step by step, including how financing choices affect your return.

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Last updated: October 25, 2026

Written and maintained by Dan Dadovic, Commercial Director at Ezoic Inc. & PhD Candidate in Information Sciences. On the energy side, Dan has hands-on experience with residential solar panel installation, DIY battery bank construction, off-grid power systems, wind power, and EV ownership/driving, all from building, maintaining, and operating his own systems.

Disclaimer: Calculator results are estimates based on theoretical formulas. Actual performance varies with temperature, battery age, load patterns, and equipment condition. For critical electrical work, consult a licensed electrician.

Methodology reviewed by Doc. dr. sc. Damir Topić, Assistant Professor, FERIT Osijek.