These solar calculators help homeowners in the UK, Ireland and the rest of Europe size, price and get the most from solar panels and home batteries. Each tool is free, works on your phone, shows its formula and working, and starts with example figures from sources such as EU PVGIS, the Energy Saving Trust and Ofgem that you can replace with your own.
Quick answer: Solar calculators turn a few numbers from your bill, roof and quote into answers: how many panels you need, what they cost, how much electricity they make, what exports earn and whether a battery pays back. Start with the solar panel cost and how many solar panels calculators, then check output, export income and battery savings.
Which Solar Calculator Do You Need?
Pick the calculator that matches the question you are trying to answer right now.
- Planning a system: the how many solar panels calculator and the solar roof space calculator.
- Comparing quotes: the solar panel cost calculator and the solar panel finance calculator.
- Checking output and savings: the solar panel output calculator, the solar panel calculator and the solar export calculator.
- Adding storage: the solar battery savings calculator.
- Roof angle: the solar panel angle calculator.
- Off grid cabins, vans and sheds: the off grid solar calculator and the solar charge controller calculator.
How Much Electricity Do Solar Panels Make in Northern Europe?
Each kWp of south facing panels at the best tilt makes about 900 to 1,050 kWh a year across the UK, Ireland and nearby countries, according to EU PVGIS data used in these calculators.
| Location | Yearly yield per kWp | June per kWp | December per kWp |
|---|---|---|---|
| London | 1,023 kWh | 120 kWh | 38 kWh |
| Dublin | 988 kWh | 114 kWh | 37 kWh |
| Amsterdam | 1,027 kWh | 126 kWh | 29 kWh |
| Hamburg | 980 kWh | 124 kWh | 24 kWh |
| Copenhagen | 1,053 kWh | 139 kWh | 18 kWh |
| Edinburgh | 908 kWh | 108 kWh | 24 kWh |
Summer months make three to eight times more than December, which matters for batteries and off grid systems. For your own address, the PVGIS tool from the EU Joint Research Centre gives a yield you can type into the custom yield box of any solar calculator here.
How Do These Solar Calculators Work Out Savings?
Solar saves money in two ways: every kWh you use yourself avoids buying it at your import rate, and every kWh you export earns your export rate.
Because import rates are usually more than twice export rates, the share of solar power you use at home matters as much as the size of the system. The calculators default to the Ofgem price cap unit rate of 26.32p for October to December 2026 and an example export rate of 12p, the figure the Energy Saving Trust quotes for the Smart Export Guarantee. Change both to match your tariffs.
Solar Calculator FAQs
How many solar panels does an average UK home need?
For 2,700 kWh a year with a London yield of 1,023 kWh per kWp, you need about 2.6 kWp, or seven 430 Wp panels. Use the how many solar panels calculator with your own use and location.
How much does a home solar system cost in the UK?
The Energy Saving Trust puts a typical 4.5 kWp system at around £7,600 installed. Batteries add around £5,000 to £8,000. Use the solar panel cost calculator with your own quote.
Are solar panels worth it in Ireland and the EU?
Higher electricity prices in many EU countries make each kWh you use yourself worth more. Enter your tariff in euros and a PVGIS yield for your address to see the savings for your home.
Do I need planning permission for solar panels?
In England most roof mounted panels on houses are permitted development, with extra rules for listed buildings and conservation areas. Check the Planning Portal or your local council, and the rules for your own country.
Can I trust the results?
Each calculator shows its formula and working, uses sourced example figures and lets you enter your own numbers. Results are estimates for planning. Electrical work must be designed and installed by a qualified, certified installer.
Checked October 2026. Sources: EU Joint Research Centre PVGIS, Energy Saving Trust, Ofgem energy price cap, HMRC VAT Notice 708/6.