A typical 4.4kW solar panel system in England has a payback period of about 8 to 10 years at late 2026 prices. On our figures it is 8.0 years in Brighton, 8.8 years in London and 9.7 years in Manchester, for a family home using 3,500 kWh a year and exporting surplus at 12p per kWh. Add a battery and payback stretches to roughly 10 to 12 years, although your total saving each year goes up.
- 8 to 10 years payback for a 4.4kW system across England at a 12p export rate
- £668 to £812 a year saved and earned, Manchester to Brighton, in our worked examples
- 4.1p vs 12p export rate is the difference between a 13 and a 9 year payback in Birmingham
- 25 to 30 years typical panel warranty, so most of a system's life comes after payback
Most payback figures online are a single number with no workings. Below we show every step, so you can swap in your own usage, tariff and price.
The payback sum
Payback period is simply the upfront cost divided by what the system saves and earns each year:
Payback (years) = system price / (value of solar you use + export income)
Each part needs a real number:
- System price. Our 4.4kW package (10 x 440W panels with a hybrid inverter) is from £6,495, including scaffolding and at 0% VAT. For comparison, the government's MCS cost data for 2025/26 gives a median of £1,546 per kW for 4 to 10kW systems, which would be about £6,802 for 4.4kW.
- Generation. We used PVGIS, the European Commission's solar modelling tool, for a south-facing roof at 35 degrees in each town. A 4.4kW system makes 3,898 kWh a year in Manchester and 5,100 kWh in Brighton.
- Solar you use at home. Without a battery, much of your solar arrives in the middle of the day when many homes use little, so a large share is exported. We assumed 1,400 kWh a year, 40% of a 3,500 kWh home's demand.
- Value of that solar. Every unit you use is one you do not buy. The Ofgem price cap unit rate for October to December 2026 is 26.32p per kWh.
- Export income. Everything else goes to the grid under the Smart Export Guarantee. We used 12p per kWh, the current Outgoing Octopus rate.
Worked example: a 4.4kW system in Manchester
- Generation: 886 kWh per kWp x 4.4kW = 3,898 kWh a year.
- Used at home: 1,400 kWh x 26.32p = £368.48.
- Exported: 3,898 - 1,400 = 2,498 kWh x 12p = £299.76.
- Yearly benefit: £368.48 + £299.76 = £668.24.
- Payback: £6,495 / £668.24 = 9.7 years.
Run the same sum in Brighton, where the roof makes 5,100 kWh, and the export share rises to 3,700 kWh (£444.00). The yearly benefit becomes £812.48 and payback falls to 8.0 years. The saving on your own use is the same in both towns in our model, because the extra southern sunshine mostly arrives on summer middays when your home is already covered.
Payback by town
Same 4.4kW system at £6,495, same 3,500 kWh home, same assumptions as above. The battery column uses our 4.4kW plus 5.8kWh battery package from £9,295, explained further down.
| Town | Output a year | Yearly benefit (12p export) | Payback at 12p export | Payback at 15p export | Payback at 4.1p export | Payback with 5.8kWh battery |
|---|---|---|---|---|---|---|
| Manchester | 3,898 kWh | £668 | 9.7 years | 8.7 years | 13.8 years | 11.6 years |
| Leeds | 4,162 kWh | £700 | 9.3 years | 8.3 years | 13.5 years | 11.1 years |
| Birmingham | 4,277 kWh | £714 | 9.1 years | 8.1 years | 13.4 years | 11.0 years |
| London | 4,510 kWh | £742 | 8.8 years | 7.8 years | 13.1 years | 10.6 years |
| Bristol | 4,536 kWh | £745 | 8.7 years | 7.7 years | 13.1 years | 10.6 years |
| Southampton | 4,752 kWh | £771 | 8.4 years | 7.5 years | 12.8 years | 10.3 years |
| Brighton | 5,100 kWh | £812 | 8.0 years | 7.0 years | 12.5 years | 9.8 years |
Two lessons jump out. Location matters, but less than people think: the gap between Manchester and Brighton is under two years. Your export tariff matters more. Choosing a 4.1p flat SEG rate over a 12p tariff adds about four years to payback everywhere. Our guide to the Smart Export Guarantee explains how to pick one, and you can check local figures on our pages for solar panels in Manchester and Brighton.
Does a battery pay back faster?
A battery lets you use more of your own solar in the evening, so the yearly benefit rises. But it adds to the upfront cost, and some energy is lost charging and discharging it. Here is the Manchester sum again with our 4.4kW plus 5.8kWh battery package at £9,295:
- Used at home: the battery lifts direct use from 1,400 kWh to 2,450 kWh (70% of the home's 3,500 kWh). 2,450 x 26.32p = £644.84.
- Battery losses: to deliver the extra 1,050 kWh, the battery must store about 1,180 kWh, based on a round-trip efficiency of 89% (the figure Tesla publishes for Powerwall 3). 1,050 / 0.89 = 1,180.
- Exported: 3,898 - 1,400 - 1,180 = 1,318 kWh x 12p = £158.16.
- Yearly benefit: £644.84 + £158.16 = £803.00, about £135 more than panels alone.
- Payback: £9,295 / £803.00 = 11.6 years.
So on solar alone, the battery lengthens payback. The picture changes if you also charge the battery from the grid on a cheap overnight rate in winter, when the panels cannot fill it. If you have an EV and a tariff such as Intelligent Octopus Go (8p per kWh between 11:30pm and 5:30am), each kWh you shift saves the difference between that rate, plus losses, and your daytime rate. Our guides on what size solar battery you need and on solar panels with a battery go through this in detail.
Simple rule: if you are out all day and your export rate is low, a battery helps payback. If you are on a 12p or better export rate and use a lot of power in daylight, panels alone usually pay back sooner.
What moves the number
How much solar you use yourself
Each kWh you use saves 26.32p; each one you export earns 12p. Shifting 300 kWh a year from export to home use, by running the washing machine and dishwasher at midday, adds 300 x (26.32p - 12p) = £42.96 a year. On the Manchester example that trims payback from 9.7 to 9.1 years.
Energy prices
We used flat prices for every year, which is cautious. If unit rates rise, your savings rise with them and payback shortens. If they fall, payback lengthens. Standing charges (54.83p a day on the current cap) are not affected by solar, so do not count them as a saving.
VAT after March 2027
Residential solar panels and batteries are zero rated for VAT until 31 March 2027, then 5% from 1 April 2027. On a £6,495 system that is an extra £324.75, which takes the Manchester payback from 9.7 to 10.2 years.
Panel ageing and inverter replacement
Panels lose output slowly, around 0.5% a year on the median of the long-term studies reviewed by the US National Renewable Energy Laboratory. The inverter usually needs replacing once in a system's life; the Energy Saving Trust puts the cost at around £800. Neither has much effect on a 9 or 10 year payback, but both matter for lifetime returns.
Your roof
East or west-facing roofs make about 15 to 20% less than south-facing ones, which adds a year or two. Shading adds more. See whether your roof is suitable for solar.
What you get after payback
Payback is only half the story. Using the Manchester example, and allowing for 0.5% a year panel ageing at flat 2026 prices:
- Total benefit over 25 years: £668.24 x 23.56 (the sum of the yearly output factors after ageing) = about £15,744.
- Less the system price of £6,495 and one inverter replacement at about £800.
- Net gain: about £8,449 over 25 years, before any price rises.
That is why we prefer to talk about lifetime value rather than payback alone. A 9.7 year payback on a system warranted for 25 years or more leaves over 15 years of free electricity to come.
Honest caveats
- Our 1,400 kWh self-use figure is an assumption. A retired couple at home all day may use more; a household out from 8 to 6 may use less. Your smart meter data is the best guide.
- Export rates are variable. The 12p Outgoing Octopus rate can change, and some higher rates are only available if you buy your system from that supplier.
- If you move house before payback, you do not lose the money, but you depend on the buyer valuing the system. Our guide to solar panels and selling your house covers this.
- PVGIS figures are long-run averages. A dull year will come in lower and a sunny one higher, so judge the system over several years.
If you want the sum done for your own home, our solar savings calculator takes your postcode, roof and usage. Or book a free survey and we will give you a fixed written price, which is the only number that really settles a payback calculation.
Sources
Costs: DESNZ solar PV cost data 2025/26. Unit rate and standing charge: Ofgem energy price cap, October to December 2026. Export rates: Outgoing Octopus and Octopus SEG tariff. Off-peak rate: Intelligent Octopus Go. Generation: our modelling with PVGIS, European Commission Joint Research Centre. VAT: HMRC VAT Notice 708/6. Battery efficiency: Tesla Powerwall 3 datasheet. Panel ageing: Jordan and Kurtz, Photovoltaic Degradation Rates, NREL. Inverter cost: Energy Saving Trust, solar power facts.
