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Solar PV Yield Estimator
Estimate realistic UK solar generation from region, roof orientation, pitch, shading, and system size. See annual yield, monthly output, self-consumption, exports, SEG income, total bill savings, and carbon reduction in one place.
Estimated results
3,990 kWh/year
4.0 kWp system · 10 panels · about 17.0 m² of roof
Specific yield
998 kWh/kWp
Self-consumed on site
1,556 kWh
Exported to grid
2,434 kWh
SEG export income
£134/year
Total bill saving
£515/year
CO₂ avoided
826 kg/year
Monthly generation profile
Typical UK seasonalityWhat this estimate assumes
Uses region-specific UK irradiance with orientation, pitch, and shading adjustments. Real output also depends on inverter sizing, exact azimuth, local weather, temperature, soiling, and whether trees or chimneys affect the array at key times.
Methodology
How this solar yield estimate works
The model starts with typical annual specific yield for the selected UK region, expressed in kWh per installed kWp. South England is set highest, with lower baselines for the Midlands, North, Scotland, Wales, and Northern Ireland.
It then applies practical adjustments for roof orientation, roof pitch, and shading. South-facing roofs at around 30-40° perform best, while east/west and flat arrays typically deliver a little less. Shading reductions are deliberately meaningful because even partial shading can materially reduce annual generation.
Savings are split into self-consumed solar electricity and exported electricity. Self-consumed energy offsets grid electricity at the selected standard UK electricity rate, while exports earn a typical Smart Export Guarantee value of 5.5p/kWh.
Self-consumption is estimated from array size and roof direction using a realistic domestic range rather than assuming every unit generated is used on site. Homes with batteries, EV charging, heat pumps, or high daytime demand may achieve better on-site use than shown here.