Solar Panel Savings Calculator
Solar savings come from the electricity your panels generate offsetting what you would buy from the grid, so payback depends on your system size, sunlight and power price. Enter your details to estimate yearly savings and payback time.
Work out your payback period, ROI, savings per year and over 25 years, plus the CO₂ you avoid, for any rooftop solar PV system — from your electric bill, system cost, size and local sun hours. Works worldwide in your own currency.
How this solar savings calculator works
Going solar comes down to two numbers: how much electricity your photovoltaic (PV) panels make, and what that electricity is worth. The calculator estimates your first-year generation as system size (kW) × peak sun hours × 365 days, scaled by a performance factor of about 0.8 to allow for inverter, heat, wiring and soiling losses. It then values the power you use on-site at your electricity rate, and any surplus you export at the feed-in or net-metering credit you enter, to get your yearly saving.
From there it projects 25 years, the length of a typical panel warranty. Each year the electricity rate rises by your annual-increase figure while output slips by your degradation figure, so later years usually save more in dollars even as the panels age. Adding those savings and subtracting your net cost gives your payback year (when the running total first covers the cost), your lifetime net savings, and your return on investment (lifetime profit ÷ net cost).
Did the federal solar tax credit end in 2026?
Yes — for homeowners who buy their own system. The 30% Residential Clean Energy Credit (Section 25D) that the Inflation Reduction Act had extended through 2032 was repealed early by the One Big Beautiful Bill Act, signed in July 2025. It no longer applies to expenditures made after 31 December 2025, so a homeowner-owned system placed in service in 2026 or later receives $0 in federal tax credit.
A few things still soften the blow: a project completed and switched on by the end of 2025 can still be claimed on a 2025 tax return (and unused credit carries forward); lease and PPA arrangements let the third-party owner claim the separate commercial credit (Section 48E, available through 2027) and pass some value on; and many state, local and utility incentives, plus net metering, remain. Because of this change the calculator defaults the credit to 0% — set it higher only if a real incentive applies to you.
Solar incentives around the world (2026)
The maths of solar is the same everywhere — generation × price, minus cost — but the incentives differ a lot by country, and they largely decide whether solar panels are worth it where you live. Pick your currency above, enter any upfront rebate as a percentage, and put your export or feed-in price in the export field. Here is the 2026 picture at a glance (always confirm the current figures with your own government or utility):
| Country | Upfront help (2026) | Reward for surplus power |
|---|---|---|
| United States | 30% federal credit ended 31 Dec 2025; some state & local rebates and SREC income remain | Net metering (varies by state & utility) |
| United Kingdom | 0% VAT on qualifying installs (to Mar 2027); ECO4 for eligible homes | Smart Export Guarantee (~4–15p/kWh, supplier-set) |
| Canada | No federal residential credit; provincial rebates + interest-free Greener Homes Loan | Net metering, near retail in many provinces |
| Australia | Upfront STC rebate (~A$400–600/kW, phasing out by 2030) + state battery rebates | Feed-in tariff (~2–9c/kWh, set by retailer) |
| New Zealand | No national subsidy; some council low-interest loans | Buy-back / feed-in ~7–16c/kWh (retailer-set) |
| Malaysia | Solar ATAP (replaced NEM in Jan 2026), via SEDA | Export offset at the System Marginal Price |
| Europe (e.g. Germany) | 0% VAT in several countries; PV income tax-free in Germany | EEG-style feed-in (~12c€/kWh, 20-yr in Germany) |
To model any of these, put your upfront rebate in the incentive box (for example a A$1,500 rebate on a A$9,000 system is about 17%) and your export price in the export / feed-in credit box. The US federal credit is 0% for 2026 purchases, so US homeowners should leave the incentive at 0 unless a state or local program applies. The same tool works whether you have the UK’s SEG, Australia’s feed-in tariff, Malaysia’s Solar ATAP, the Philippines’ net metering or a New Zealand buy-back rate — so it doubles as a solar payback calculator for the UK, Australia, Canada and beyond.
What changes your solar payback and ROI
- Electricity rate — the higher your rate, the more each kWh of solar is worth, and the faster you break even. In high-rate states like California and Hawaii, payback comes years sooner than where power is cheap.
- Sun hours — a sunny desert roof can out-produce a cloudy northern one by 50% or more for the same panels.
- Install price — residential solar commonly runs about $2.50–$3.50 per watt installed; a lower price shortens payback directly.
- Rate increases — utility power has historically risen a few percent a year, which quietly grows your savings over time.
- Degradation — panels lose roughly 0.3–0.8% of output per year, a small drag on the later years.
- Net metering / feed-in — the export credit you enter decides what your surplus power is worth; power you use yourself is always valued at your full retail rate.
The environmental payback of solar
Every kilowatt-hour your panels make is one the grid does not have to. On the US average grid that avoids roughly 0.8 pounds of CO₂ per kWh (EIA), so a typical home system keeps many tons of carbon out of the atmosphere across its life. The calculator translates that into everyday terms — trees planted, cars taken off the road for a year, and gallons of gasoline not burned — using US EPA equivalency factors, so it doubles as a solar PV carbon-savings calculator.
Worked example
Related tools: pairing solar with an electric car? See how much you could save switching from petrol with our electric vehicle savings calculator, or compare going solar against investing the same money using the compound interest calculator.
How to use it & key terms
Enter your system size and cost, your electricity rate and daily sun hours, then press Calculate for your payback, 25-year savings and CO₂ avoided.
| Term | What it means |
|---|---|
| System size (kW) | The rated power of your solar array. |
| Peak sun hours | The daily hours of full-strength sun used to estimate generation. |
| Payback period | The years for savings to repay the net system cost. |
| Degradation | The roughly 0.3–0.8% a year that panel output slowly declines. |
| Net metering / feed-in | Credit for surplus power you export to the grid. |
| kWh | A unit of electricity; savings are kWh generated × your rate. |
Sources & methodology
First-year generation = system size (kW) × peak sun hours × 365 × 0.8 performance factor. Each year's saving = electricity used on-site × your rate (escalated by your annual-increase input) + any surplus exported × your export / feed-in credit (held flat, since export rates rarely rise); generation is reduced each year by your degradation input. Payback is the year the running savings first cover the net cost (system cost less any incentive); lifetime net savings and ROI (lifetime profit ÷ net cost) run over a 25-year panel life. CO₂ avoided uses ~0.8 lb/kWh and is converted with EPA equivalency factors (≈0.060 t CO₂ per urban tree over 10 years, ≈4.6 t per car-year, ≈0.00889 t per gallon of gasoline).
Sources: US EIA (average electricity price and ~0.8 lb CO₂/kWh generation factor); US EPA Greenhouse Gas Equivalencies Calculator; NREL PVWatts and panel-degradation studies (~0.5%/yr); IRS and the One Big Beautiful Bill Act (H.R.1) for the end of the Section 25D residential credit on 31 Dec 2025; Ofgem Smart Export Guarantee (UK), energy.gov.au Small-scale Renewable Energy Scheme (Australia) and provincial net-metering programs (Canada) for the international summary.
Self-consumption: the solar lever most in your control
Solar power pays you back in two different ways, and they are not worth the same. Every kilowatt-hour you use in the house the moment it is generated replaces one you would otherwise have bought, so it is worth your full retail electricity rate. Every kilowatt-hour you do not use spills onto the grid as export, and that surplus earns only your feed-in or net-metering credit, which in most places is markedly lower than retail. The share of your generation that you manage to use on-site — your self-consumption ratio — therefore quietly shapes your payback. Two identical systems on two identical roofs can return very different savings simply because one household is home using the power and the other is exporting most of it.
The encouraging part is that self-consumption is one of the few levers you control without spending a penny. Solar produces most in the middle of the day, which is exactly when many homes are empty, so shifting flexible loads into daylight hours captures power that would otherwise be exported cheaply. Running the dishwasher and washing machine on a daytime timer, heating water in the early afternoon, and charging an electric car or a pool pump while the sun is high all turn low-value export into full-value self-use. None of it changes how much your panels make; it changes how much of that output you keep at the higher price, and that is what shortens the payback.
A home battery takes the same idea further by storing the midday surplus and releasing it in the evening, when you are back home and the panels have stopped — lifting self-consumption well above what daytime habits alone can reach. That extra value comes at the cost of the battery itself, so it is worth modelling on its own rather than assuming it always pays. To reflect any of this in the calculator, be realistic about the split between the power you will actually use on-site and the power you will export, and set the export credit to your true feed-in rate rather than your retail rate. The wider the gap between those two prices, the more every point of self-consumption is worth to you.
- Self-use beats export — power used at home earns the full retail rate.
- Shift loads into daylight — timers on big appliances capture midday output.
- A battery lifts it further — stored midday power covers the evening, at a cost.
Frequently asked questions
How is solar payback calculated?
Payback is your net system cost divided by your yearly savings. This tool goes further and projects each year on its own — raising your electricity rate by your annual increase and lowering output by your degradation rate — so the break-even year is more realistic.
Is there still a federal solar tax credit in 2026?
Not for homeowners who buy their own system. The 30% Residential Clean Energy Credit (Section 25D) ended on 31 December 2025 under the One Big Beautiful Bill Act, so a system placed in service in 2026 earns no federal credit. Projects finished by the end of 2025 can still be claimed on a 2025 return, and lease/PPA or state incentives may still help — which is why the credit field defaults to 0%.
What is a good solar payback period?
For a purchased grid-tied system, roughly 8–12 years is common. It is shorter where electricity is expensive or incentives apply, and longer where power is cheap. After payback, the rest of the panels' 25-year life is profit.
Is solar still worth it in 2026 without the tax credit?
It depends on your electricity rate, sun hours and install price. Payback is longer now that the federal credit has ended, but many homes still come out ahead over 25 years — especially where electricity is expensive and utility rates keep climbing.
How much can solar panels save me?
Power you use yourself is valued at your electricity rate; any surplus you export is valued at the feed-in or net-metering credit you enter (zero by default). The calculator projects that saving across 25 years using your rate-increase and degradation assumptions.
What is panel degradation?
Panels slowly lose output as they age — about 0.3–0.8% per year — and are often warrantied to still make around 80–90% of their rating after 25 years. The calculator trims each year's generation by your degradation rate.
What is net metering?
It is a billing arrangement that credits you for surplus power your panels send to the grid. Enter your export price in the export / feed-in credit box: power you use yourself counts at your retail rate and any surplus at that export rate. Leave it at zero to stay conservative.
How much CO₂ does solar avoid?
Each kWh from the US grid emits roughly 0.8 lb of CO₂ on average, so over 25 years a typical home system avoids many tons. The tool converts that into trees, cars and gasoline using EPA equivalency factors.
Can I use this calculator outside the United States?
Yes. Pick your currency ($, C$, £, A$ or €), then enter your local electricity rate, system cost, any upfront rebate as a percentage and your export or feed-in credit per kWh. The payback, ROI, savings and CO₂ maths is the same everywhere — only the prices and incentives change.
How do I include net metering or a feed-in tariff?
Put your export price per kWh in the export / feed-in credit box. Power you use on-site is valued at your retail rate, while surplus sent to the grid is valued at that export rate — covering US net metering, the UK Smart Export Guarantee and Australian or Canadian feed-in tariffs.
What solar incentives are there in the UK, Canada and Australia in 2026?
The UK offers 0% VAT on qualifying installs plus Smart Export Guarantee export payments. Canada has no federal residential credit but many provinces offer near-retail net metering, provincial rebates and an interest-free federal Greener Homes Loan. Australia gives an upfront STC rebate that phases out by 2030, plus state battery rebates and feed-in tariffs. Enter whichever applies in the incentive and export boxes.
What is the maintenance cost of solar panels?
Solar panels are low-maintenance — with no moving parts, most owners spend little beyond occasional cleaning and an inspection, often a few hundred dollars a year or less. The main mid-life cost is usually replacing the inverter once, roughly every 10–15 years. This calculator focuses on energy savings, so budget any maintenance you expect separately.
How do I calculate solar savings myself?
Estimate yearly generation as system size (kW) × daily peak sun hours × 365, then multiply by about 0.8 for real-world losses. Value the power you use at your electricity rate, add any exported surplus × your feed-in rate, and divide the net cost by that yearly saving for a rough payback. This tool does it all and projects 25 years with rate rises and degradation.
Why are my solar panels not saving money?
Usual culprits: an under- or over-sized system, a low electricity rate, a high install price, shading or a poor roof orientation, and weak export/net-metering terms that pay little for surplus. Fixed grid charges also stay on the bill. Put honest numbers in above and the payback and 25-year figure will show if it really pays off.
How much will solar panels save per year?
Roughly your first-year generation valued at your electricity rate. A typical 6 kW system making ~7,900 kWh a year saves anywhere from a few hundred to well over a thousand in your currency, depending on your rate — the calculator shows your exact first-year and 25-year savings.
Are solar panels worth it in the UK, Australia, Canada or New Zealand?
Often yes, even without a big upfront subsidy, because power is expensive. Typical 2026 payback is roughly 7–10 years in the UK and New Zealand, about 4–7 years in sunny Australia with the STC rebate, and similar across much of Canada with near-retail net metering. Set your currency, then enter your local rate, cost and export price to see your own payback and 25-year savings.