Property-specific solar estimate
Solar roof calculator for UK homes
Check an exact UK property for solar panels, compare Google’s roof model with a PVGIS generation estimate, then test savings and payback using your own electricity use and tariff.
Step 1
Find the exact property
Choose a full address so the roof model is matched to the building, not the centre of its postcode.
Your address is sent to Google to locate the property. Energy Review does not save it or include it in analytics.
How the solar roof calculator works
Google’s result is a building-specific technical estimate. PVGIS is a separate location and orientation model. A close match is useful reassurance; a wide gap is a reason to ask an installer which roof planes, losses and shading assumptions are in their proposal. It is not a reason to average the figures.
The financial result is deliberately simpler. It separates electricity used in the home from electricity exported, values each at the rate you enter, and divides the illustrative installed cost by that annual benefit. It does not predict future tariffs or finance costs.
Before signing an installation contract
Ask for a site survey, an itemised generation estimate, the assumed shading and system losses, equipment warranties, and evidence that the installer and products meet any requirements attached to your chosen export tariff. You can also use our seven-day solar forecast after the system is installed.
If you do not want to select an address, use our quicker solar panel cost and payback calculator. It estimates costs, savings and export earnings from the system details you enter rather than a building model.
Questions about the estimate
How accurate is this solar roof calculator?
Where available, the calculator uses Google Solar roof geometry and shading-aware panel layouts, then lets you run the same roof segments through PVGIS. Both are estimates and neither replaces an installer survey, structural assessment or quotation.
What happens when detailed roof data is unavailable?
The calculator keeps the selected property coordinates and switches to a manual system description. PVGIS then estimates generation for the location, system size, roof pitch and direction you provide.
Does Energy Review store my address?
No. The address is used during the calculation to obtain property coordinates and is not saved by Energy Review or included in analytics events. Google processes the address lookup under its own terms and privacy policy.
Why can Google Solar and PVGIS show different figures?
They use different weather datasets and modelling methods. Google models the detected roof and nearby shading, while PVGIS calculates each supplied roof plane with an explicit system-loss assumption. The calculator shows both rather than silently averaging them.
What makes a roof suitable for solar panels?
Usable roof area, direction, pitch, shading and the roof structure all matter. This calculator can model area, direction, pitch and some nearby shading where detailed data exists, but an installer still needs to assess condition, access and structural suitability on site.