One of the most common questions we hear at D&R Energy is whether solar panels work well enough in the South West of England to justify the investment. The short answer is a resounding yes. In fact, the South West has the highest solar irradiance of any region in the UK, making it one of the best places in the country to install solar panels. This article explains why the South West is so well-suited to solar energy and what performance you can realistically expect from your system.
South West Solar Irradiance: The Numbers
Solar irradiance measures the amount of solar energy that reaches a given area, and it directly determines how much electricity your solar panels will generate. The South West of England receives more solar radiation than any other UK region, with annual solar yields of 950-1,100 kWh per kWp (kilowatt-hours per kilowatt-peak). This means that for every kilowatt of solar panel capacity you install, you can expect to generate between 950 and 1,100 kilowatt-hours of electricity per year.
To put this in context, the national average for the UK is approximately 800-950 kWh per kWp. The South West's superior irradiance means your solar panels will generate up to 15% more electricity than an identical system installed in the Midlands, and up to 20-25% more than one in Scotland. This higher output directly translates to greater energy savings, faster payback periods, and a better return on your investment.
How Much Electricity Will My System Generate?
Using the South West's solar irradiance figures, here is what you can expect from the three most common residential system sizes:
- 3.6kWp system (9 panels): 3,420-3,960 kWh per year, covering a significant portion of a 2-3 bed home's annual electricity needs.
- 4.5kWp system (12 panels): 4,275-4,950 kWh per year, close to or exceeding the average UK household's annual electricity consumption of approximately 3,500-4,000 kWh.
- 6.3-7.0kWp system (18 panels): 5,985-7,700 kWh per year, enough to cover even high-consumption households with EV charging and home office equipment.
These figures assume a south-facing roof with an optimal tilt angle of approximately 30-35 degrees. South-east and south-west facing roofs typically achieve 95% of these figures, while east or west-facing roofs achieve approximately 80-85%. Even on a less-than-ideal roof orientation, the South West's strong irradiance means your system will still perform well above the national average.
Do Solar Panels Work on Cloudy Days?
Yes, solar panels absolutely work on cloudy days. Modern solar panels are designed to capture diffuse light as well as direct sunlight, which means they continue generating electricity even when the sky is overcast. On a typical cloudy day in the South West, your panels will generate approximately 10-25% of their peak output. On a bright but overcast day, this can rise to 50-70% of peak output.
The UK's climate means that a significant portion of your annual solar generation comes from diffuse light on cloudy and partially cloudy days. Solar panel manufacturers account for this in their performance ratings, and the annual yield figures of 950-1,100 kWh per kWp already include the effect of cloudy days, rainy periods, and shorter winter days. Your system does not need constant sunshine to deliver strong financial returns.
Seasonal Variation in the South West
Solar generation varies throughout the year, with the highest output in summer and the lowest in winter. In the South West, a typical monthly generation pattern for a 4.5kWp system looks like this:
- Summer months (May-August): 500-600 kWh per month. Long days and high sun angles mean your panels generate more than most homes consume, with the surplus charging your battery or being exported for SEG payments.
- Spring and Autumn (March-April, September-October): 300-450 kWh per month. Still strong generation, covering the majority of household electricity needs.
- Winter months (November-February): 100-200 kWh per month. Shorter days and lower sun angles reduce output, but your panels still generate meaningful electricity. Battery storage helps bridge the gap by storing any surplus for evening use.
The key to maximising year-round performance is combining solar panels with battery storage. A battery ensures that surplus energy generated during the day is available in the evening when your household consumption is typically highest, rather than being exported to the grid at a lower rate.
Bristol and Somerset: Local Performance
Bristol and Somerset sit in the heart of the South West's high-irradiance zone. Bristol, in particular, benefits from its relatively mild climate and coastal proximity, which can reduce the frequency of prolonged cold snaps that sometimes reduce panel efficiency in other regions. The city's latitude of approximately 51.4 degrees north is optimal for solar generation in the UK context.
D&R Energy has completed hundreds of installations across the Bristol and Somerset area, and our real-world data consistently confirms that local systems meet or exceed the expected yield figures. Whether your property is in Bristol, Somerset, or Gloucestershire, you can be confident that your solar panels will deliver excellent performance.
The Verdict
The South West is the best region in the UK for solar energy. With annual yields of 950-1,100 kWh per kWp, up to 15% above the national average, and effective performance even on cloudy days, solar panels in Bristol and Somerset deliver outstanding financial returns. Combined with 0% VAT, Smart Export Guarantee payments, and potential grant funding, there has never been a better time to go solar in the South West. Contact D&R Energy for a free quote and find out exactly how much your property could generate.
