How the calculator works
Find your roof on the map, place panels and enter your electricity bill. You get estimated production, yearly savings and payback, free and without giving contact details.
- Find your roof. Search your address on the satellite map.
- Place your panels. Draw the layout on your roof and choose the panel wattage.
- Enter your bill. Add your monthly spend and electricity rate.
- See your estimate. System size, yearly production, yearly savings, payback and 20-year net savings.
How the estimate is calculated
- Production comes from an hour-by-hour solar simulation for your location over a full year.
- Yearly savings count only the solar power that offsets what your bill says you use.
- The 20-year figure assumes electricity prices rise 2.5% a year and panel output falls 0.6% a year, then subtracts the estimated system cost.
This is an estimate. It does not model shade from nearby buildings or trees, and the final design and price depend on a site visit by an installer.
Common questions
Do I need to give my contact details to see the estimate?
No. You see the full estimate first. Contact details are only needed if you ask for a quote.
How long does the calculation take?
Usually a minute or two, because the simulation runs for your exact location.