| Expected output (PVGIS) | 1,025 kWh a year per 1 kWp, central London, 35 degree pitch, south-facing, 14% losses |
|---|---|
| Distribution licence area | London Power Networks plc (the London distribution licensee on Ofgem's list) |
| Roof panels in England | May project no more than 0.2 m from a pitched roof and sit no higher than the highest part of the roof |
| Export payments | The Smart Export Guarantee covers installations located in Great Britain |
What a London roof can produce
The European Commission’s PVGIS tool gives a neutral benchmark because anyone can run it with the same inputs. For central London, with a 35 degree pitch, south-facing panels and 14% system losses, it returns about 1,025 kWh a year for every 1 kWp installed. On those inputs, a 4 kWp array would model near 4,100 kWh a year.
Real roofs differ, so treat that as a yardstick rather than a promise. For comparison, the same tool gives about 1,060 kWh per kWp for Exeter. The gap is modest, so shade from neighbouring buildings and roof direction will often move your figure more than the postcode does.
Some London terraces still suit an east-west split, because a narrow plot may have no south-facing slope at all. Our guide to east-west against south-facing layouts explains the trade-off. Ask each installer to state the assumed output in kWh and the inputs behind it. If a number sits far above the yardstick, ask why.
Planning rules in England
Planning rules differ across the UK nations, and England has its own order. Under Part 14 of the England order, panels on a house roof count as permitted development when they stick out no more than 0.2 metres from a pitched roof slope. They also cannot sit higher than the highest part of the roof, not counting a chimney.
Two limits matter most in London. First, the order excludes a listed building, so you would need to apply for permission. Second, in a conservation area, panels cannot go on a wall that fronts a highway. Our planning permission guide walks through these checks in order.
Your council can confirm whether your street sits in a conservation area. Do not rely on the installer’s word alone, because the council holds the record. Ask for the answer in writing before the install date.
Flats and flat roofs
If you live in a flat, note that the order has separate wording for a block of flats. It excludes a listed block there too. On the flat roof of a house, equipment cannot rise more than 0.6 metres above the highest part of the roof.
If your building has a flat roof, read our note on solar panels on a flat roof before you accept a mounting design. Permitted development is not the only hurdle for a flat, since lease terms may need the owner’s consent. Ask the freeholder early.
What to check on the survey visit
A good survey in a dense city looks at more than the roof. The surveyor should note chimneys, dormers, roof lights and any taller buildings nearby, because each one can cast shade for part of the day. Ask to see the shading assumption in the quote.
Next, check the route for cables and the spot for the inverter. In a flat or a tight terrace, a loft or hallway may still be the only option. Ask whether the inverter will be quiet enough for a bedroom wall, and whether the installer will make good any holes.
Finally, ask for the plan in a drawing. A sketch of the panel layout on your own roof lets you compare quotes fairly. It also shows whether a proposal quietly leaves out part of the roof.
Access, scaffolding and timing
Terraced streets and tight rear yards can change how an installer reaches the roof. Because we hold no sourced London price for access, do not accept a vague line item. Instead, ask for scaffolding to appear as its own line, and ask who arranges any road or pavement permissions.
Our scaffolding cost guide explains how to read that line. Similarly, the note on how long installation takes helps you judge whether a quoted timetable looks realistic.
Connecting to the grid
Ofgem’s licensee list names London Power Networks plc as the distribution licensee for London. Your installer normally handles the paperwork, although you should know who files it. National Grid describes G98 as the route for fully type-tested installations under 16 A per phase, where the installer fits the system and then tells the network operator. National Grid and SSEN both ask for this notice within 28 days of commissioning.
Larger systems, or sites with more than one generator, can need approval first. Ask your installer which route applies and who files it. Put the answer in writing.
Getting paid for exports
The Smart Export Guarantee covers installations located in Great Britain, so London homes qualify. Licensed suppliers set their own rates and contract lengths, although the rate must always be above zero. Ofgem tells generators to shop around.
Our smart export guide explains how the payments work.
London’s group-buying scheme
The Mayor of London’s page describes Solar Together London as a group-buying programme that iChoosr runs. It says over 3,000 homes now have panels through the scheme. It also says some customers needed help after one installation company failed.
If you see the scheme on offer, read the current terms on the official page, because they can change. Then compare its price with at least one independent quote.
Comparing London quotes
Start with the line-by-line quote comparison so each quote covers the same scope. Then check the price against our solar panel cost guide. Prices vary, so get written quotes.
Before you sign, work through the questions to ask an installer and the list of what belongs in a solar quote. Planning to compare other nations too? Our pages on what households in the south west should check and how Welsh rules differ show where the rules change.
When you have two or three quotes, the free enquiry form can match you with MCS-certified installers.