Tools

Is a plug-in solar kit worth it for you?

An honest payback number — counting only the electricity you'd actually use, because a plug-in system earns nothing for what it exports.

Kit price

Panels, inverter, mount and cable — the all-in price.

Panel rating (W DC)

Output is capped at 800 W AC by law; panels above that only add a little.

Which way will it face?

Shading

Who's home in the daytime?

Plug-in solar only saves money on electricity you use while the sun is out. Anything you don't use flows out to the grid — and on a plug-in system, you are not paid for it.

Electricity unit rate (p/kWh)

Pre-filled with the Ofgem price-cap rate for Oct–Dec 2026. Check your bill and change it if yours differs.

Simple payback

Your kit would pay for itself in about

—

saving £0 a year on your bill

This is a guide, not financial advice. It uses the government's own yield assumptions for an 800 W plug-in system under average UK sunshine (DESNZ impact assessment, July 2026), the SAP shading factors, and a flat electricity price. Real output varies with weather, location and how well the panels are placed; it also falls slightly each year as panels age. Panels above 800 W DC are credited at half value for the part above the inverter cap, and anything above 2000 W DC is not allowed under the plug-in route. The 20-year figure ignores inflation, inverter replacement and the chance you move house.

Read the full guide: Plug-in solar panels: are they worth it in the UK? — the legal rules since 27 August 2026, the battery catch, how to notify your network operator, and a checklist for renters and leaseholders.