How much do solar panels save per month in the UK?

The headline: roughly £60–£100 a month

Take a typical 4kW system on an unshaded south-facing UK roof. It generates around 3,400kWh a year (estimate, at ~850kWh per kWp). At the October 2026 price cap of 26.32p/kWh, every unit you generate and use yourself is a unit you don't buy — worth 26.32p. Every surplus unit you export earns 3–6p under the Smart Export Guarantee.

A household that is home during the day might self-consume half its generation: 1,700kWh × 26.32p ≈ £447 a year of avoided imports, plus ~1,700kWh × 4p ≈ £68 of export payments. Total: around £515 a year, or £43 a month. A high daytime user — working from home, running the washing machine and dishwasher at midday — can push self-consumption toward 70% and land nearer £700–£900 a year, roughly £60–£75 a month (all estimates).

Add a battery and the picture improves further: storing the midday surplus for the evening peak typically lifts savings by another 30–50% (estimate), taking a keen household toward £90–£120 a month on average. Our solar savings estimator runs these numbers for your exact usage.

But "per month" is misleading — solar is seasonal

Here is the honest shape of the year. A UK system makes roughly three-quarters of its annual energy between April and September. In June and July, a 4kW system can wipe out most of a typical daytime electricity bill — savings of £100–£150 in a good month (estimate) are realistic for high daytime users.

In December and January, the same system might generate a tenth of that. Monthly savings collapse to £10–£20 (estimate), and you are buying almost everything from the grid again. Anyone quoting you a flat monthly saving is averaging the summer bounty across the winter drought. The annual total is what matters — and it is the annual total the payback maths runs on.

What moves your number up or down?

When you use electricity. This is the single biggest lever. A unit used at 1pm is worth 26.32p; the same unit exported at 1pm and bought back at 7pm nets you roughly 22p less. Timers on hot water, dishwashers and washing machines are free money.

Roof direction and shade. South-facing and unshaded is the benchmark everything else is measured against. East-west still performs respectably; heavy shade can gut the economics.

Your tariff. The 26.32p figure is the October 2026 price cap. If you are on a cheaper fixed deal, savings shrink; on an expensive standard variable tariff, they grow. Export tariffs vary too — 12–16p/kWh is available when your import tariff is with the same supplier, which changes the self-consumption arithmetic.

System size vs usage. Oversizing relative to your daytime use just exports more at 4p. The sweet spot is a system sized to your actual consumption — see how many panels you need.

Will it eliminate your bill?

No — and be wary of anyone who says otherwise. Even the best system leaves two things untouched: the winter shortfall, when you buy most of your power from the grid, and the standing charge of roughly £180–£200 a year, which you pay simply for being connected. A realistic expectation is cutting your electricity bill by a third to two-thirds, not erasing it.

Why the monthly figure swings so much

Solar in Britain is a seasonal animal. A 4kW system that averages ~£55 a month over the year (estimate) might deliver £70–£110 in June and only £15–£25 in December (estimates). This is why "per month" is slightly misleading: you save little in winter when you need power most, and a lot in summer when you need it least.

Three things flatten that curve. A battery lets you shift daytime surplus into the evening, pushing self-consumption from ~35% toward 70%+ and making each kWh worth the full 26.32p instead of a few pence of SEG export. Shifting usage — running the washing machine, dishwasher and hot water at midday rather than 7pm — is free and worth real money. And SEG payments land quarterly or annually depending on your supplier, so they don't smooth the monthly picture at all.

The honest way to read any "per month" figure: it's the annual saving divided by twelve. Budget for the annual number, not the June one.

FAQs

How much do solar panels save per month in the UK?

Roughly £60–£100 a month on average across the year for a typical 4kW system at October 2026 prices (estimate) — far more in summer, far less in winter.

Do solar panels save money in winter?

Only a little. December generation can be a tenth of June's, so winter monthly savings are typically £10–£20 (estimate).

Does a battery increase solar savings?

Yes — typically by 30–50% (estimate), by shifting midday surplus into the expensive evening peak instead of exporting it for 3–6p.

How much does the Smart Export Guarantee pay?

About 3–6p per kWh on standalone tariffs in October 2026, or 12–16p when your import tariff is with the same supplier. A 4kW system might earn £80–£200 a year (estimate).

Can solar panels eliminate my electricity bill?

No. The winter shortfall and the ~£180–£200 annual standing charge remain. Expect a substantial cut, not zero.