This dataset estimates how location, direction and mounting angle affect balcony solar generation. We ran the European Commission's PVGIS model for twelve UK cities, six panel directions and three angles, giving 216 annual scenarios and 2,592 monthly values. These are climate-model outputs, rather than measured installations, product tests or forecasts for the coming winter.
Download all monthly generation data as CSV. The file includes city coordinates, panel direction, angle, month, energy per 1 kWp, annual energy, loss allowance, radiation database and download date.
South-facing vertical panels by city
The examples below scale the 1 kWp model to a 600 Wp array at 90° from horizontal. This is a consistent comparison; it does not include the shadows cast by nearby buildings or railings.
| City | Annual generation | December–February |
|---|---|---|
| London | 445.7 kWh | 85.3 kWh |
| Exeter | 453.4 kWh | 86.6 kWh |
| Brighton | 496.1 kWh | 92.5 kWh |
| Norwich | 456.1 kWh | 84.4 kWh |
| Nottingham | 430.2 kWh | 81.3 kWh |
| Birmingham | 426.1 kWh | 80.8 kWh |
| Leeds | 422.5 kWh | 78.4 kWh |
| Manchester | 387.9 kWh | 65.7 kWh |
| Newcastle | 430.1 kWh | 78.3 kWh |
| Cardiff | 447.1 kWh | 79.4 kWh |
| Edinburgh | 409.5 kWh | 67.6 kWh |
| Belfast | 409.7 kWh | 70.0 kWh |
Reproduce the model
Every request used PVGIS 5.3 PVcalc, PVGIS-SARAH3, crystalline silicon, free-standing mounting, 1 kWp peak power, 14% system losses and the default terrain horizon. Directions use PVGIS's azimuth convention: 0° south, −45° south east, 45° south west, −90° east, 90° west and 180° north. Slopes are 35°, 60° and 90° from horizontal.
For example, the London vertical south-facing request is:
https://re.jrc.ec.europa.eu/api/v5_3/PVcalc?lat=51.5074&lon=-0.1278&aspect=0&angle=90&peakpower=1&loss=14&pvtechchoice=crystSi&mountingplace=free&raddatabase=PVGIS-SARAH3&usehorizon=1&outputformat=json
Read the official PVGIS API documentation for parameter definitions. Monthly E_m and annual E_y are energy output in kWh. Scale by panel rating in kWp; the 14% loss allowance is already included.
What the data can and cannot tell you
The cities are representative points, rather than regional averages or postcode estimates. Terrain shading is included; individual buildings, overhangs, trees, parapets and rails are not. The model does not simulate a specific microinverter's output cap, your hourly self-consumption or the fitted cost. A 1 kWp reference is a scaling basis, rather than a claim that every 1 kWp array works without clipping on an 800 VA inverter.
Use the savings calculator to explore 300–800 Wp scenarios with your unit rate, self-use and shade allowance. Our winter guide explains the monthly comparison. For buying decisions, check the dated register tracker separately; energy modelling does not establish product compliance or permission to install.
For publishers and researchers
You are welcome to reuse our comparison tables and accompanying commentary with attribution to Balcony Solar Guide and a link to this methodology page. Credit the underlying modelling to the European Commission's Joint Research Centre, PVGIS 5.3. Preserve the assumptions and describe the figures as modelled. This permission covers our added material; the underlying PVGIS data remains subject to its own terms.
You can also embed the free calculator. For a source check, a different comparison or a correction, contact hello@balconysolarguide.co.uk.
Have a real installation to contribute?
We would like to compare these estimates with measured UK results. Send the kit and inverter model, panel wattage, direction, angle, approximate region, an itemised installation cost and dated generation exports. Please remove addresses, account numbers and other identifying information. Include whether you own or rent, any relevant permissions, and which photos or results you permit us to publish. We will agree attribution before using them.