Solar Panel Savings Calculator
See how much a solar PV system could save you. Enter your system size, local electricity rate and sunshine to estimate yearly savings, payback period, break-even point and bill reduction.
Sets a typical annual yield (kWh per kW installed). Adjust below for your exact area.
Payback period
Saves about £752 in year one
Where the savings come from (year 1)
How this year's generation splits between money saved on your bill and income from exporting excess power.
Cumulative savings vs cost
| Year | Generated | Savings | Net position |
|---|---|---|---|
| Year 1 | 3,800 kWh | £752 | -£5,248 |
| Year 2 | 3,781 kWh | £771 | -£4,477 |
| Year 3 | 3,762 kWh | £790 | -£3,686 |
| Year 4 | 3,743 kWh | £810 | -£2,876 |
| Year 5 | 3,725 kWh | £830 | -£2,046 |
| Year 6 | 3,706 kWh | £851 | -£1,196 |
| Year 7 | 3,687 kWh | £872 | -£324 |
| Year 8 | 3,669 kWh | £893 | £570 |
| Year 9 | 3,651 kWh | £916 | £1,485 |
| Year 10 | 3,632 kWh | £938 | £2,424 |
| Year 11 | 3,614 kWh | £962 | £3,385 |
| Year 12 | 3,596 kWh | £986 | £4,371 |
| Year 13 | 3,578 kWh | £1,010 | £5,381 |
| Year 14 | 3,560 kWh | £1,035 | £6,416 |
| Year 15 | 3,542 kWh | £1,061 | £7,477 |
| Year 16 | 3,525 kWh | £1,087 | £8,565 |
| Year 17 | 3,507 kWh | £1,114 | £9,679 |
| Year 18 | 3,490 kWh | £1,142 | £10,821 |
| Year 19 | 3,472 kWh | £1,170 | £11,991 |
| Year 20 | 3,455 kWh | £1,199 | £13,191 |
| Year 21 | 3,438 kWh | £1,229 | £14,420 |
| Year 22 | 3,420 kWh | £1,260 | £15,680 |
| Year 23 | 3,403 kWh | £1,291 | £16,971 |
| Year 24 | 3,386 kWh | £1,323 | £18,294 |
| Year 25 | 3,369 kWh | £1,356 | £19,650 |
Net position is total savings minus the installation cost. The first green row is your break-even point. Assumes 0.5% panel degradation a year and your chosen electricity price rise.
Quick tips
- • A typical home system is 3–5 kW and uses 15–25 m² of roof.
- • The more solar you use directly at home, the faster it pays back — self-use savings beat export rates.
- • A battery raises self-use (often to 60–80%) but adds to the upfront cost.
- • Use the electricity price from a recent bill for the most realistic result.
Typical annual yield (per kW)
Good to know
These figures are estimates for planning only. Real savings depend on roof orientation and shading, your daily usage pattern, tariff, battery storage and future energy prices. Always get a quote and a site-specific yield estimate from an accredited installer.
About the Solar Panel Savings Calculator
The Solar Panel Savings Calculator turns a solar quote into the numbers that actually matter: how much you save each year, how long the system takes to pay for itself, and what it's worth over its lifetime. It combines your system size, local sunshine, electricity price and how much power you use at home to estimate yearly savings, the payback period, the break-even point and your overall return.
Solar savings come from two places. Every kilowatt-hour you use as it's generated is one you don't buy from the grid, saving you the full electricity price. Anything you don't use is exported and earns a lower export rate. Because self-used energy is worth far more than exported energy, your "self-use" percentage is one of the biggest levers on payback — which is why batteries, timing appliances for daytime and home working all improve the return. The lifetime view assumes panels lose about 0.5% of output a year and lets you factor in future electricity price rises, so the break-even point reflects real-world conditions rather than a flat estimate.
How to Use the Solar Panel Savings Calculator
- 1 Pick your location to set a typical annual yield, then fine-tune the kWh-per-kW figure if you have a site-specific estimate.
- 2 Choose your system size in kW with the quick chips or type an exact figure from your quote.
- 3 Enter your electricity and export rates from a recent bill, plus how much of the solar you expect to use at home.
- 4 Add the installation cost and, optionally, your yearly home usage and an expected annual price rise for a fuller picture.
- 5 Read your results — payback period, yearly savings, bill reduction and the year-by-year break-even table update instantly as you type.
Frequently Asked Questions
How is the payback period worked out? +
The calculator adds up your savings year by year — money saved by using solar at home plus income from exported power — and finds the point where the running total equals your installation cost. That crossover is the payback period and the break-even point. It also allows for panels slowly producing less over time and any electricity price rise you enter.
What is "self-use" and why does it matter so much? +
Self-use is the share of solar power you consume as it's generated, rather than exporting it. It matters because each self-used unit saves the full electricity price you'd otherwise pay, while exported units usually earn a much lower rate. A typical home without a battery self-uses 30–50%; adding a battery or running appliances during the day can push this to 60–80% and shorten payback considerably.
What annual yield should I use for my area? +
Annual yield is how many kilowatt-hours each kW of panels produces in a year, and it depends on latitude, weather, roof angle and orientation. As rough guides: the UK and northern Europe get around 900–1,000 kWh per kW, the US averages about 1,300–1,500, and very sunny regions can exceed 1,700. Use the location presets as a starting point, then refine with a local estimate for the most accurate result.
Does the calculator account for panels degrading over time? +
Yes. Solar panels lose a small amount of output each year — the model assumes about 0.5% annually, which is typical of modern panels backed by 25-year performance warranties. This slight decline is built into the year-by-year table and the 25-year savings and ROI figures, so the long-term totals aren't overstated.
Are these figures a guarantee of savings? +
No — they're planning estimates. Actual savings depend on your exact roof, shading, usage pattern, tariff, whether you add battery storage and how energy prices change in future. Treat the results as a realistic ballpark, and always get a site-specific quote and yield estimate from an accredited installer before committing.