Average Monthly Electric Bill with Solar Panels UK (2026)
What does a typical UK electricity bill look like after installing solar panels? Real monthly figures by household size, with and without battery storage, plus how to push your bill even lower.
One of the most asked questions before installing solar is: what will my electricity bill actually look like afterwards? The honest answer is “it depends”, but with realistic UK assumptions you can model it within £10–£20 a month. This guide breaks down typical post-solar bills, including standing charges, by household size, system size, and whether you have a battery.
The headline: average monthly electric bill with solar panels in the UK
For a typical 3-bedroom UK household using 2,700 kWh a year, with a 4kW solar system and no battery, the average post-solar electricity bill is around £40–£55 a month, down from £75–£100 a month without solar. Adding a battery typically cuts this further to £15–£35 a month.
Below we break that down, including what the standing charge alone costs, why bills don’t hit zero, and how to push them as low as possible.
Average bills before and after solar (2026 prices)
Based on the Ofgem Default Tariff Cap of 26.7p/kWh and a 65p/day standing charge (single-rate, dual-fuel, average UK):
| Household | Annual usage | Bill: no solar | Bill: 4kW solar | Bill: 4kW solar + battery |
|---|---|---|---|---|
| 1-bed flat | 1,800 kWh | £60/mo | £35/mo | £24/mo |
| 2-bed semi | 2,200 kWh | £68/mo | £40/mo | £24/mo |
| 3-bed semi | 2,700 kWh | £80/mo | £48/mo | £28/mo |
| 4-bed detached | 3,800 kWh | £105/mo | £68/mo | £42/mo |
| 5-bed + EV + heat pump | 7,500 kWh | £185/mo | £130/mo | £75/mo |
Bills after solar include a Smart Export Guarantee credit for surplus electricity sent back to the grid (typically 15p/kWh on Octopus Outgoing or similar), netted off your import cost.
Why bills don’t go to £0
Even with a generously sized solar + battery system, most UK homes still pay something each month. The reasons:
- Standing charge. A flat daily fee for being connected to the grid, currently 65p/day, or about £20/month. You pay this even if you import zero electricity. Switching to a tariff with a higher unit rate and lower standing charge can help if you import very little.
- Winter months (Nov–Feb). A 4kW solar system generates roughly 80kWh in December vs 600kWh in June. Battery or not, you’ll import most of your winter usage from the grid.
- High-demand events. An electric oven, kettle, EV charger, or heat pump can draw 3–9kW, more than even a sunny solar peak can supply, so the difference comes from the grid (or your battery).
What changes month-to-month
Solar bills are highly seasonal. Here’s the typical month-by-month profile for a 4kW system on a 3-bed semi (2,700 kWh/year):
| Month | Generation | Bill (no battery) | Bill (with 10kWh battery) |
|---|---|---|---|
| January | 110 kWh | £75 | £62 |
| February | 180 kWh | £62 | £48 |
| March | 320 kWh | £42 | £25 |
| April | 450 kWh | £25 | £10 |
| May | 520 kWh | £20 | £8 |
| June | 540 kWh | £18 | £8 |
| July | 510 kWh | £20 | £10 |
| August | 440 kWh | £25 | £12 |
| September | 340 kWh | £38 | £22 |
| October | 210 kWh | £55 | £38 |
| November | 110 kWh | £70 | £55 |
| December | 80 kWh | £82 | £68 |
Many solar households are in credit with their supplier from April to September, then draw on that credit through winter. Annual budgets even out into manageable monthly direct debits.
How to push your bill even lower
- Switch to a smart tariff. Octopus Flux and Agile reward exporting at peak times (4–7pm). For solar + battery homes, this can knock another £150–£300 a year off bills. See our Octopus tariffs comparison.
- Add a battery (if you don’t have one). Without storage, you self-consume only 25–35% of generation; with a battery, that climbs to 70–85%. More on solar batteries.
- Run heavy loads during the day. Dishwashers, washing machines, tumble dryers, and EV charging. Use timers or smart plugs to align with peak generation.
- Add a solar diverter for hot water. Diverts surplus solar to your immersion heater instead of exporting it. Saves around £100–£200/year on a gas-heated home.
- Consider a 3-rate tariff. Flux pays 20–30p/kWh for export 4–7pm vs 4–6p import overnight. Combined with a battery, this is the cheapest tariff structure for solar homes in 2026.
Real-world example: a 3-bed semi in Manchester
Sarah and James have a 3-bed semi in Manchester, two adults, no kids, both work from home 2 days a week. Annual usage 2,500 kWh. They installed a 4.2kW system and 9.5kWh battery in October 2024.
- Pre-solar bill: £74/month average
- Post-solar bill (Year 1, with battery, on Octopus Flux): £22/month average
- Annual saving: £624 in bill reduction + £180 in SEG export = £804/year
- System cost: £11,200 with 0% VAT
- Estimated payback: 11.5 years
Their highest single month was £52 (December); their lowest was £6 in May (mostly standing charge).
FAQs
Will solar panels eliminate my electricity bill entirely?
No, the standing charge alone is around £20/month, and winter generation is too low to cover usage. A well-sized solar + battery system can get you to £15–£35/month for an average home, but not £0.
How much does a 4kW solar system save per year?
For a typical UK home, a 4kW system saves £350–£500/year without a battery and £700–£950/year with a battery. Higher-usage homes save more.
What is the average UK electricity bill in 2026?
For a 3-bed home using 2,700 kWh/year on the Default Tariff Cap, around £80/month (~£960/year). Higher in winter, lower in summer.
Is solar still worth it with cheap energy tariffs?
Yes. Even on Octopus’s cheapest fixed tariffs, the unit rate is around 23–25p/kWh, well above the 4–6p you can charge a battery overnight on Flux or Cosy. Solar plus battery on a smart tariff is the cheapest electricity any UK home can run on in 2026.
Get a personalised estimate of your post-solar bill from MCS-certified installers near you using our free quote tool.
John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He researches every battery and inverter brand against manufacturer datasheets, MCS and Ofgem data, and feedback from the MCS-certified installers in our directory before publishing.