How does solar PV yield vary across UK regions?

Solar yield depends on location, roof design and weather, so a regional average is only a starting point. Official Feed-in Tariff analysis reports a 9.2% median solar load factor for its 2024/25 sample [S1]. Use that historical evidence alongside a location-specific generation model and your electricity demand before judging a commercial roof's output. Checked October 2026.

Last checked 16 October 2026

How does solar PV yield vary across UK regions?

Use regional data to sense-check a proposal, then ask for a forecast for your actual roof. The official 2024/25 Feed-in Tariff analysis places South West England highest, closely followed by the East of England and North East, all around a 9.5% median load factor. London was lowest, followed by Scotland and North West England [S1]. These are historical sample results, not standard outputs for new commercial installations.

The same report describes overlapping regional distributions [S1]. For your purchasing decision, that means a regional ranking should prompt questions rather than settle the design. Request your site’s location, slope, direction and loss assumptions. Compare those inputs with the physical survey before accepting a forecast.

The table deliberately avoids invented regional energy bands. Its observations come from the report’s text and chart, rather than estimates read from unlabelled points on a graph [S1].

For a business in East Anglia, use East of England guidance alongside your own survey. Being in a leading region does not establish a particular roof’s output or financial result.

What do load factor and yield mean for your roof?

A kilowatt (kW) measures power; a kilowatt-hour (kWh) measures energy. Kilowatt-peak (kWp) is the rated power of the array under test conditions [S4]. Specific yield expresses annual energy per unit of installed peak power, usually written kWh/kWp/year. Ask the installer to label units so you can compare different system sizes.

Load factor is actual generation divided by the energy that continuous operation at rated capacity would produce over the period [S1]. It is not the percentage of daylight captured or the percentage of your bill removed. The historical sample and a design forecast also describe different populations, so do not substitute one for the other without explaining the purpose.

For an arithmetic illustration, assume a non-leap year has 8,760 hours and a system achieves a 10% load factor. Its specific yield would be 8,760 × 0.10 = 876 kWh/kW for that year. The 10% input is an assumption, not a new regional observation. This calculation shows how the units connect; use the actual period when analysing records.

Read commercial solar sizing to translate a verified design yield into a trial array capacity. Keep the distinction between the proposed array and the site’s electricity demand.

How do you check a UK solar yield calculator?

PVGIS, the European Commission’s Photovoltaic Geographical Information System, accepts a location and system inputs and produces generation estimates [S2]. Ask for a saved model with each quote. Request confirmation that the location is your premises rather than a convenient nearby postcode.

Use this comparison checklist when reviewing competing models:

• Ask whether each model uses the same installed capacity and roof layout.
• Identify separate roof faces and ask how their outputs were combined.
• Request a schedule of losses and any extra site adjustments.
• Ask which shading information comes from the survey.
• Keep monthly results beside annual totals.
• Identify whether export restrictions have been applied outside the generation model.

These are review steps, not prescribed design settings. Avoid setting every quote to an optimistic orientation simply to make the totals comparable. Instead, compare the actual buildable layouts and explain their differences. Ask for a revised calculation if the accepted roof layout changes during survey or procurement.

How much electricity will solar produce in winter?

Request monthly output instead of a single annual total divided equally across the calendar. The official sample shows a seasonal pattern [S1]. PVGIS can supply average monthly production for the proposed grid-connected design [S3]. Use those results to investigate your site’s winter needs, rather than importing a household winter ratio.

Make a monthly worksheet with generation, direct site use, surplus and grid imports. A pub with evening demand, a depot charging overnight and a summer attraction need different consumption profiles. Ask which loads can actually move into generation hours without affecting operations. Keep uncertain changes in a separate scenario.

For illustration, assume a 50 kWp array has specific yield scenarios of 800, 900 and 1,000 kWh/kWp/year. Multiplying capacity by yield gives 40,000, 45,000 and 50,000 kWh/year. These are sensitivity assumptions, not verified outputs assigned to particular regions. Do not use them to promise winter supply or export income.

How should yield affect your investment decision?

Hold tariffs and demand assumptions constant while comparing output scenarios. Then repeat the comparison with different consumption overlap. This separates weather and design risk from the value of the electricity used. Read self-consumption versus export for the financial calculation.

Ask the installer to show curtailed energy and model limitations explicitly. No site-specific regional forecast is published here because a consistent set of location calculations was not verified. Your own roof model remains the next evidence needed, alongside structural suitability.

What should you do next?

Request the saved generation model, monthly output and a demand comparison. Use installer selection to assess who can explain that evidence.

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