How much does balcony solar save?

An 800Wp kit generates roughly 384–680 kWh a year depending on position: a south-facing tilted panel at the top of that range, an east/west vertical one at the bottom. Used at home at the 26.32p cap rate that is about £101–£179 a year if you use all of it, and less for what you export.

Is balcony solar worth it without a battery?

It has to be, for now: the UK plug-in rules don't allow self-installed kits with batteries. It's often worth it if you use power during the day; without an export payment, generation you can't use at the time is largely wasted.

Balcony Solar Savings Calculator

Plug-in solar is legal in Great Britain up to 800W of output, with up to 2,000W of panels. Set your panel size and see what a kit generates, what the 800W cap clips, and what it saves. The battery option models an electrician-installed battery, because plug-in kits can't include one under the current rules.

Panel capacity1,200 Wp

Inverter output is fixed at 800W and panels can total up to 2,000W, the UK plug-in limits. Surplus above 800W is clipped.

Balcony position

Kit cost600Battery size (electrician-installed)0 kWhElectricity price26.32p

Price cap average; enter a postcode for your region's rate.

Export rate0pUsed at home (daytime)50%

Panels generate

816 kWh/yr

Lost to 800W cap

41 kWh/yr

Annual saving

£102

Payback

5.9 yrs

Little clipping at this panel size, so the saving depends mostly on how much you use during daylight.

Estimate only: real output depends on your exact balcony, shading and usage pattern.

Assumptions

Yield: 0.85 / 0.68 / 0.48 kWh per Wp for south-tilted / SE-SW-or-vertical-south / E-W-or-shaded, sanity-checked against PVGIS (EC JRC PVGIS)
Clipping: Piecewise curve calibrated to German Balkonkraftwerk simulations: 2,000Wp on 800W loses ~20%
Import price: 26.32p/kWh, Ofgem price cap, 1 October to 31 December 2026; enter a postcode above the calculator for your region's Octopus rates (Ofgem)

Rates checked 20 September 2026. Check them again before you commit to anything.

Balcony Solar Savings Calculator

Assumptions

Next steps