Cambridge in the PVGIS data
PVGIS models Cambridge at 1,041 kWh per kWp a year. That assumes a south-facing roof at a 35 degree tilt. The figure sits just above the London value of 1,019.
A 4 kWp system therefore comes to about 4,164 kWh a year. London would give about 4,076 kWh and Aberdeen about 3,572 kWh for the same system. Cambridge lands about 2% above London and 17% above Aberdeen.
Norwich, on the nearby list, scores 1,032, so the two East of England cities are only 9 kWh per kWp apart. The page on solar panels in Norwich lets you compare them. In practice, roof direction and shade will outweigh that small gap.
Best and worst months
July is the best month in Cambridge at 124.3 kWh per kWp, with June at 123.8 and May at 123.0. December is the weakest at 36.2. The best month is therefore about 3.4 times the worst.
May to August supply about 47% of the year. November, December and January supply about 12%. The summer to winter ratio is a little lower than in Plymouth or Brighton.
The value of that output depends on how you use it. Ofgem’s price cap sets electricity at 26.32p per kWh at the time of writing. Exports typically earn around 12p per kWh.
Export and the Smart Export Guarantee
The Smart Export Guarantee pays you for power you send to the grid. Suppliers with at least 150,000 domestic customers must offer a tariff, and Ofgem does not set the rate. Our guide to the Smart Export Guarantee compares the options.
Your system needs an MCS certificate and a meter that records export. The scheme covers England, Scotland and Wales. Check the current offers before you choose a supplier, because rates change often.
Batteries
A battery stores midday surplus for the evening. DESNZ data puts the median retrofit cost at about £890 per kWh for 6 to 11kWh batteries. Our post on whether a solar battery is worth it weighs that against likely savings.
You can also read about solar battery storage before you ask for prices. Heat pumps raise electricity use, so a planned post on solar panels and heat pumps covers how they fit with solar.
Tilt and direction
PVGIS gives an optimal tilt of 41 degrees for Cambridge. At that angle output rises to 1,046 kWh per kWp, which is 5 kWh above the baseline. However, your roof pitch will usually decide the angle.
Direction matters more. Energy Saving Trust says east or west-facing systems tend to get 15% to 20% less than a south-facing one. Test each roof face before you rule one out.
Planning and the council
Cambridge is in England, so the national rules apply. Roof panels on a house are normally permitted development. They must project no more than 200mm and stay below the highest part of the roof, as the Planning Portal sets out.
Listed buildings need planning permission and listed building consent. In a conservation area, you cannot fit panels to a wall, balcony or roof enclosure that fronts a highway. Cambridge City Council is the planning authority, so ask it about Article 4 directions on your street.
UK Power Networks and G98
Cambridge is usually in the UK Power Networks area, although your postcode decides it. The Energy Networks Association has a lookup tool. Your installer normally files the notification.
Under G98, a type-tested system up to 16A per phase, about 3.68kW on a single phase, connects first. The installer notifies the operator within 28 days. A larger system needs G99 approval before installation, and the operator may limit export.
Cost and quotes
DESNZ puts the median cost for systems up to 4kW at £1,595 per kW for 2025 to 2026. A 4 kWp system therefore costs about £6,400 without a battery. Solar installs are currently zero-rated for VAT until 31 March 2027.
Solar Yield is an independent estimator and referral service, and we do not install anything. We pass enquiries to MCS-certified installers. Our page on solar panel installation describes the service.
You can check any installer on the MCS Find an Installer search. Ask each one to show the kWh per kWp and shade factor behind their estimate. For a wider view, the page on solar output in London gives the capital’s value. Further north, solar panels in Leicester shows the East Midlands.
Next steps
Use the Solar Yield calculator to test your roof. Then send one enquiry through the get quotes page. Compare each estimate with the PVGIS figures above.