UK Regional Solar Performance
Solar panel performance varies across the UK based on sunshine hours, latitude, and local weather patterns. See how your region compares and what output you can expect from a solar installation.
| Region | Sun Hours/Year | Output (kWh/kWp) | Performance | Optimal Tilt | ROI Years |
|---|---|---|---|---|---|
South West England Best performing region in the UK with highest sunshine hours | 1,750 | 1050 | Excellent | 35° | 6 |
South East England Excellent solar potential, slightly higher installation costs | 1,700 | 1020 | Excellent | 35° | 6.5 |
East of England Low rainfall and flat terrain beneficial for solar | 1,650 | 1000 | Excellent | 36° | 7 |
Greater London Urban heat island effect can slightly reduce efficiency | 1,550 | 950 | Very Good | 35° | 7 |
East Midlands Good central location with moderate performance | 1,500 | 920 | Very Good | 37° | 7.5 |
West Midlands Slightly more rainfall than eastern regions | 1,450 | 900 | Very Good | 37° | 7.5 |
Wales Western coastal areas receive more rainfall | 1,400 | 880 | Good | 38° | 8 |
Yorkshire & Humber Eastern coast benefits from lower rainfall | 1,400 | 870 | Good | 38° | 8 |
North West England Higher rainfall but still economically viable | 1,350 | 850 | Good | 38° | 8.5 |
North East England Coastal areas can be windier, affecting maintenance | 1,350 | 840 | Moderate | 39° | 8.5 |
Northern Ireland Growing solar market with good government incentives | 1,300 | 820 | Moderate | 39° | 9 |
Scotland (Lowlands) Longer summer days partially compensate for less sun | 1,300 | 810 | Moderate | 40° | 9 |
Scotland (Highlands) Variable weather but solar still viable in many areas | 1,200 | 780 | Moderate | 42° | 10 |
* Output figures based on south-facing roof at optimal tilt angle with no shading. Actual results may vary based on specific installation conditions.
kWh per kWp
This measures how much energy (kWh) you generate per kilowatt of solar capacity installed. A 4kWp system in the South West would produce approximately 4,200 kWh annually (4 x 1,050).
Irradiance
Solar irradiance measures the power of sunlight per square metre. Higher irradiance means more energy available for your panels to convert into electricity.
Optimal Tilt Angle
The best angle for panels varies by latitude. Southern regions benefit from lower angles (35°), while northern areas perform better with steeper tilts (40-42°) to capture lower sun angles.
ROI Calculation
Based on average installation costs of £5,000-7,000 for a 4kWp system, electricity prices of 24p/kWh, and SEG export rates of 4-15p/kWh. Actual ROI depends on your energy usage patterns.
Roof Orientation
South-facing roofs produce 100% of potential output. South-east/west achieve 95%, east/west 80-85%. Even north-facing roofs can generate 50-60% in northern latitudes.
Shading
Trees, chimneys, and nearby buildings can significantly reduce output. Even partial shading on one panel can affect the entire string. Consider microinverters for shaded installations.
Temperature
Solar panels actually work better in cooler temperatures. Scottish installations benefit from this effect, partially offsetting lower sunshine hours.
Panel Quality
Premium panels (21-22% efficiency) can produce 10-15% more than budget panels (17-18% efficiency) in the same conditions.
Solar output varies dramatically throughout the year. Understanding this helps you plan battery storage and energy usage patterns.
Summer
June - August
of annual output
Daylight: 16-17h
Peak generation period, may export significant surplus
Spring
March - May
of annual output
Daylight: 12-14h
Good generation with increasing daylight hours
Autumn
September - November
of annual output
Daylight: 10-12h
Decreasing output, cooler temps improve efficiency
Winter
December - February
of annual output
Daylight: 7-8h
Lowest output, but panels still generate on cloudy days
Best for: Maximum solar generation and fastest ROI
Consider: Battery storage to capture summer surplus
System size: 3-4kWp often sufficient for average home
Export potential: High - may export 50%+ of generation
Best for: Balanced generation and self-consumption
Consider: Slightly larger system (4-5kWp) to offset lower output
Tip: East-west split arrays can spread generation throughout day
Export potential: Moderate - aim for 70% self-use
Best for: Summer self-sufficiency, longer payback acceptable
Consider: Larger system (5-6kWp) with battery for winter
Advantage: Cooler temps boost panel efficiency
Tip: Longer summer days (17+ hours) provide excellent generation
Calculate Your Specific Output
Get a personalized estimate based on your exact location, roof orientation, and energy usage. Our calculator uses real Met Office data for accurate predictions.
Try Our Savings CalculatorIs solar worth it in Scotland?
Yes. While output is lower than southern England, solar is still economically viable. Scottish homes often have higher electricity consumption (due to heating needs), making solar savings more impactful. The longer summer days also mean June generation can match or exceed southern installations.
Do panels work on cloudy days?
Yes, solar panels generate electricity from daylight, not direct sunlight. On overcast days, panels typically produce 10-25% of their rated capacity. Modern panels are increasingly efficient at capturing diffuse light.
Why does optimal tilt vary by region?
The sun is lower in the sky at higher latitudes. A steeper tilt angle helps panels face the sun more directly. In practice, most UK roofs (25-45°) work well across all regions, with only minor efficiency differences.
How accurate are these figures?
These are regional averages based on Met Office sunshine data and industry benchmarks. Actual performance depends on your specific roof orientation, shading, panel quality, and inverter efficiency. We recommend getting site-specific quotes from MCS-certified installers.