Bristol sits in the upper half of the UK output range. PVGIS, the European Commission’s solar model, gives about 1,023 kWh per kWp a year for a south-facing roof at 35 degrees. That figure assumes no shade and a clear view of the sky. Your own roof will differ, so use it as a starting point.
What a Bristol roof can produce
A 4 kWp system is a common size for a house. At 1,023 kWh per kWp, it would make about 4,092 kWh a year. London gets about 1,019 kWh per kWp, so Bristol matches the capital to within a fraction of a percent. Aberdeen gets about 893 kWh per kWp, so Bristol produces about 15% more than the far north.
Manchester gets about 886 kWh per kWp, so Bristol beats it by about 15% too. Even so, a shaded Bristol roof can lose more than that, because shade and direction cut output faster than latitude does.
Summer against winter
Bristol’s best month is May, at 126.2 kWh per kWp. Its worst is December, at 33.8 kWh per kWp. May therefore delivers about 3.7 times the output of December.
For a 4 kWp system, that means roughly 505 kWh in May and 135 kWh in December. Most homes use more power in winter, so a Bristol system will export in spring and summer. In winter, however, it will fall short.
Two of our posts show the pattern in more detail. The first covers how much a 4kW system generates through the year. The winter output guide explains why December is so weak.
Tilt and direction
PVGIS puts the best fixed tilt for Bristol at 39 degrees. That gives 1,025 kWh per kWp, only a little above the 1,023 you get at 35 degrees. Most pitched roofs already sit near that range.
Direction matters more. Our London run shows an east-facing roof at 35 degrees loses about 20% against south, and a west-facing one loses about 23%. The calculator lets you test your own angle and compass direction. Our page on solar battery storage covers how a battery stores summer surplus for the evening.
Planning in Bristol
In England, panels on a house roof are normally permitted development. Their limit is 200mm out from the roof slope, and they must stay below the highest part of the roof. The Planning Portal sets out the full rules.
Listed buildings need planning permission and listed building consent. In a conservation area, however, panels cannot go on a wall or roof section that fronts a highway. Bristol City Council is the planning authority, and it can tell you whether an Article 4 direction applies to your street.
The grid connection
Most of Bristol takes its power from National Grid Electricity Distribution. Since your postcode fixes the operator, use the Energy Networks Association lookup if you are unsure.
A system up to 16A per phase, about 3.68kW on a single-phase supply, falls under rule G98. Your installer tells the network operator within 28 days of commissioning. Larger systems fall under G99, which needs approval before installation, as MCS explains.
Getting quotes
Solar Yield is an independent estimator and referral service. It does not install panels. It passes your enquiry to MCS-certified installers, and you can check any installer on the MCS register.
Read our guide to solar panel installation before you compare offers. Our post on how many panels you need helps you pick a size first. MCS rules say an estimate is guidance, not a guarantee, so treat any promise of a fixed output with care.
You may also want a comparison with nearby areas. See solar output in Cardiff and the Exeter estimate for neighbouring figures. While the numbers sit close together, your roof details still decide the result.
Next steps
Use the Solar Yield calculator to estimate output for your own roof. Then send your details through our quote form to receive offers from MCS-certified installers. Estimate openly, then check it against the installer’s figures.