Glasgow has the lowest solar output of the 24 cities on Solar Yield, but it still produces useful power. PVGIS, the European Commission’s free solar model, estimates 853 kWh per kWp a year for a south-facing roof at 35 degrees. That is about 16% below London at 1,019 kWh per kWp.
Solar Yield is an independent estimator and does not install panels. This page explains what the Glasgow figures mean, so you can test an installer’s estimate against an open source.
What a typical Glasgow system could produce
Output scales with system size. A 4 kWp system could generate about 3,412 kWh a year in Glasgow, and a 4.5 kWp system about 3,839 kWh. In Aberdeen, at 893 kWh per kWp, the same 4 kWp system would give 3,572 kWh.
Ofgem’s medium household uses 2,500 kWh of electricity a year on a standard meter, according to its typical consumption values. A 4 kWp roof can therefore still out-produce that over a year. However, the amount you save depends on when you use the power.
Our explainer on kWh per kWp shows how to turn the PVGIS figure into your own estimate.
Best month and worst month
May is the strongest month in Glasgow at 115.8 kWh per kWp. December is the weakest at 19.4 kWh per kWp, so the best month produces about 6 times the worst. That is a wider seasonal swing than Oxford or Cardiff.
May, June and July together give 336.8 kWh per kWp. In contrast, November, December and January together give only 76.5 kWh per kWp. Winter output is therefore small.
Tilt and direction
PVGIS puts the optimal tilt for Glasgow at 41 degrees, with 855 kWh per kWp a year. Since a 35 degree roof gives 853 kWh per kWp, a normal pitched roof loses almost nothing.
Direction has a bigger effect. At 35 degrees, PVGIS gives 673 kWh per kWp for an east-facing roof and 683 for a west-facing one. A north-facing roof gives 469. Energy Saving Trust does not recommend north-facing panels.
Planning rules and Glasgow City Council
Scotland has its own rules. Class 6HA gives householders permitted development rights for solar panels. No part may protrude more than 1 m from the wall, roof plane, ridge or chimney. The Scottish Government’s Circular 1/2024 sets out the detail.
However, the right does not apply to a listed building, its curtilage or a World Heritage Site. In a conservation area, fit panels only on a rear elevation, or a side elevation that does not front a road. Glasgow City Council is the local planning authority. Ask the council before you buy if your home is in a conservation area.
Grid connection under SP Energy Networks
Your network operator depends on your postcode, and in Glasgow it is usually SP Energy Networks. Under G98, a type-tested system up to 16 A per phase connects first. That is about 3.68 kW on a single-phase supply, and the installer tells the operator within 28 days.
Because larger systems fall under G99, the installer must apply and get approval before installing. The operator may limit export. MCS explains both routes on its notifying network operators page.
Output over time and cost
Panels lose a little output each year. A review of nearly 2,000 measured rates found a median loss of 0.5% a year. Our post on solar panel degradation explains what that means over 25 years.
DESNZ puts the 2025 to 2026 median installed cost at about £1,595 per kW for systems up to 4 kW. That makes a 4 kWp system about £6,400, according to the DESNZ cost data. Home Energy Scotland lists support schemes, but its solar help is narrow, so check homeenergyscotland.org before you rely on it.
Our pages on solar panel installation and solar battery storage explain how referrals work. Once panels are up, our upcoming guide on whether cleaning panels increases output covers upkeep. For nearby comparisons, see the solar output figures for Edinburgh and the Aberdeen solar installation page.
Next steps
Run your own roof through the solar yield calculator first. Then use get quotes to send one enquiry to MCS-certified installers. Solar Yield passes on your request and does not install anything itself.