Solar panels in Plymouth: sizing, grid connection and planning

Sizing a system for Plymouth

Plymouth has a strong yield on the numbers, and the tilt matters little. The EU’s PVGIS tool models about 1,121 kWh a year per kWp for a south roof at 35 degrees. The ideal tilt here is near 39 degrees, giving 1,123 kWh per kWp. By comparison, Nottingham comes out at 979 kWh on the same terms.

Try a few sizes. A 3 kWp system is about 3 x 1,121, or 3,363 kWh a year. A 4 kWp system is about 4,484 kWh, and a 5 kWp system is about 5,605 kWh. These are modelled estimates, so treat them as a guide.

Which size suits you? That depends on your use and your roof space, because both set a limit. Our guide on how many solar panels you need shows how to size from your bills. A bigger array makes more power, but only the part you use or export earns you anything.

PVGIS also builds in a default 14% loss for cables, inverters, dirt and ageing. Shade and roof direction will therefore move your result further. If you want to see how cities compare, our table of solar output across 24 UK cities explains what drives the gaps.

Power you do not use

Midday output can top what a home needs. The Smart Export Guarantee fills that gap, because suppliers pay you for exported power. Ofgem notes that larger suppliers, those with at least 150,000 domestic customers, must offer a tariff. Smaller ones can join voluntarily.

Rates differ, however, so it pays to shop around. You apply directly to the supplier you choose.

Choosing an installer in Plymouth

Certification is the first test. MCS is the UK quality mark for small-scale renewables, and its search tool lets you check any firm by name. You also need MCS-certified work to claim Smart Export Guarantee payments.

Next, ask about consumer protection, since deposits can be large. Renewable Energy Consumer Code members must insure deposits and workmanship warranties. This helps if the installer stops trading while you hold an unfinished job.

Then compare at least a few quotes. Each should show the system size in kWp, the expected yearly output and the panel and inverter makes. It should also say who handles the network notification and what the warranty covers. A quote with those details is easier to compare than a single headline price.

Our page on solar panel installation explains how a typical job runs from survey to sign-off. The guide to solar panel costs shows how to read the price. Exeter is nearby, so solar panels in Exeter offers a nearby comparison.

Grid connection in the South West

Plymouth sits on the South West network run by National Grid Electricity Distribution. It is the distribution network operator, or DNO. Every new system must be reported to it.

The MCS standard sets the route by size, so ask which one yours is. Systems up to and including 16 A per phase follow G98, and larger ones follow G99. The total of all generators counts, so a solar array plus a battery can cross the line.

The MCS standard says the MCS contractor must carry out the notification. For G98, the operator asks for notice within 28 days of commissioning. Your installer should confirm the dates in writing.

Planning in Plymouth

The planning authority is Plymouth City Council. Plymouth is in England, where the rules changed on 27 August 2026. The Planning Portal explains the update, including separate rules for houses and blocks of flats.

Projects that no longer qualify can still use the earlier rules until 26 August 2027. Those rules limited panels on a wall facing a highway in a conservation area. They also excluded buildings in the grounds of a listed building.

Flats need particular care, since the roof is rarely yours alone. Stand-alone solar on a block of flats can need a prior approval step with the council. Meanwhile, leasehold terms may also need the freeholder’s consent. If your home is listed, in a conservation area or a flat, check with the council before you sign.

Next steps

Once you have a rough size and a few questions, you can ask for quotes through this site. We are an independent guide, not an installer, and nobody contacts you unless you agree. Compare what comes back against the checklist above. A good firm will not rush you.