| Expected output (PVGIS) | 1,094 kWh a year per 1 kWp, Canterbury, 35 degree pitch, south-facing, 14% losses |
|---|---|
| Distribution networks | SSEN (central southern England) and South Eastern Power Networks plc (Ofgem licensee list) |
| SSEN notification | Submit G98 Form B within 28 days of commissioning, or apply first in listed cases |
| Roof panels in England | May project no more than 0.2 m from a pitched roof and sit no higher than the roof's highest part |
What a South East roof can produce
PVGIS is the European Commission’s free solar tool. For Canterbury, with a 35 degree pitch, south-facing panels and 14% system losses, it returns about 1,094 kWh a year for each 1 kWp. That is a little higher than the 1,025 kWh it gives for central London on the same inputs, so the London figures make a useful contrast.
Treat the Canterbury number as a benchmark, not a forecast, because your own roof will change it. Direction, pitch and shade all matter. A tree on the south side can cut output, so ask how shade was handled.
Ask every installer for the expected annual kWh and the assumptions behind it. If one quote claims far more than the benchmark, ask for the shading report, since shade is one assumption that changes output. Our guide on how many panels you need shows how to turn a household’s use into a system size.
Two network operators, one region
The South East is split between more than one network operator. SSEN says it delivers power across central southern England. Ofgem’s licensee list also names South Eastern Power Networks plc and Southern Electric Power Distribution plc as distribution licensees. The ENA guide lists South Eastern England under South Eastern Power Networks and Southern England under Southern Electric Power Distribution.
So the first job is to find out which one serves your postcode. Your installer normally does this, but ask anyway, because the forms differ.
How SSEN’s process works
For up to 3.68 kW per phase at one property, SSEN sets out three steps. The installer fits equipment that meets G98 standards. Then it submits G98 Form B within 28 days of commissioning, and SSEN reviews the submission.
In some cases you must apply before you connect. These include more than one generator at a property, a total that exceeds the G98 limits, and a nearby system that the same installer fitted within the last 28 days. Our guide to G98 and G99 applications explains the two routes in plain English.
Ask the installer to send you a copy of the submission, and keep it with your MCS certificate, since it records that the notice went in.
What to check before you accept a design
A good design starts with your electricity use, not with the roof. Ask the installer to show the annual kWh they assumed for your home. Then ask how much of the output you will use yourself, because every unit you use yourself is a unit you do not buy.
Next, look at the layout drawing. It should show where each panel sits, where the inverter goes and how the cable runs. If a quote has no drawing, ask for one. A plan also helps you spot a roof face that the installer has quietly left out.
Finally, check what the quote says about scaffolding and about making good any damage. Both can add charges, so ask for them as separate lines.
Planning rules for England
England has its own permitted development rules, and they differ from those in Scotland, Wales and Northern Ireland. Under Part 14 of the England order, panels on a pitched house roof can project no more than 0.2 metres. They also cannot sit above the highest part of the roof, not counting a chimney.
The order excludes listed buildings. In a conservation area, panels cannot go on a wall that fronts a highway. If your home may be in a conservation area, ask the council before you pay a deposit. A short written reply from the planning team protects you if a neighbour complains later.
Exports and funding
The Smart Export Guarantee covers installations located in Great Britain. Licensed suppliers set their own rates and contract terms, although a rate must always be above zero. Our smart export guide shows how to compare offers.
Because we found no South East scheme on the official pages we checked, funding here follows the national picture. The grants and VAT guide lists what applies across England. Treat any “regional grant” claim in a sales pitch with caution until you see it on an official page.
Resale and warranties
Solar can matter when you sell. Our note on selling a house with solar panels covers what buyers and their solicitors ask to see. Warranty terms matter there too, because a buyer will want to know who stands behind the equipment.
Panels slowly lose output over time, so read the guide on degradation and performance warranties before you sign. Check who holds each warranty, however, since an installer that closes cannot honour its own promise.
Comparing your quotes
Line your quotes up side by side with the quote comparison checklist. Check that each one names the panels, inverter, mounting, scaffolding and grid notice, because a missing line can hide a cost. Prices vary, so get written quotes.
Two quotes can look equal while the scope differs, so compare what is included rather than the headline total. Rules change across borders too. Our pages on what West Midlands households should check and how Yorkshire and the Humber differs cover other English networks.
When you are ready, the free enquiry form can match you with MCS-certified installers.