Most UK solar panels pay for themselves in eight to eleven years, and a well-priced system on a south-facing roof in the South East can break even in under nine. Cheaper systems, higher daytime usage and a good export tariff pull that figure down. A north-facing roof, a low SEG rate or an overpriced quote push it past twelve.
This guide is written for homeowners and small businesses across Hampshire, Surrey, West Sussex and the wider South East. Every figure uses the Ofgem price cap that took effect on 1 July 2026, and every calculation is shown in full so you can swap in your own numbers.
The short answer
- Typical UK payback: 8-11 years. The Energy Saving Trust puts London at 9 years and Stirling at 12, using July 2026 fuel prices.
- Two things move the needle: what you pay for the system, and how much of the electricity you use yourself. Everything else is a rounding error by comparison.
- The Smart Export Guarantee pays you for surplus. Typical rates sit around 12p/kWh but run from about 5p to 20p, and that gap is worth more than five years of payback on a 4kW system.
- Batteries don't automatically shorten payback. At £5,000-£8,000 they often lengthen it on a standard tariff. Pair one with a time-of-use tariff and the maths flips.
- Panels last 25-30 years. You'll replace the inverter once, at around year 12, for roughly £800-£1,200.
What is the solar payback period?
Your payback period is the number of years it takes for the money a solar system saves and earns you to equal what you paid for it. Two streams feed it: the grid electricity you no longer buy, and the payments you receive for surplus electricity sent to the grid. Divide the net cost by the annual benefit and you have your answer in years.
A 4kW system costing £7,000 that delivers £670 a year of bill savings and export income breaks even in 10.4 years, depending on your usage, generation and energy costs. After that point the electricity is effectively free for the rest of the panels' working life.
Lifespan matters because it sets the size of the prize. Panels carry 25-year performance warranties and many keep generating past 30, as we cover in how long solar panels last. The inverter is the weak link, typically needing replacement around year 12 at £800-£1,200. Batteries carry 10-year warranties, which is the number that tends to undermine their payback case.
How much does a solar system cost?
The Energy Saving Trust puts the average domestic system at 4.5 kWp costing around £7,600 installed. Here's how that breaks down by size, at prices we see across the South East in August 2026.
| System size | Panels (approx.) | Roof space | Typical installed cost | Annual generation, South East |
| 3 kW | 8 | 15-18 m² | £5,000-£6,500 | ~2,850 kWh |
| 4 kW | 10 | 20-24 m² | £6,000-£8,000 | ~3,800 kWh |
| 4.5 kW | 12 | 20-30 m² | £6,800-£8,400 | ~4,275 kWh |
| 5 kW | 13 | 26-32 m² | £7,500-£9,500 | ~4,750 kWh |
| 6 kW | 15 | 30-38 m² | £8,500-£11,000 | ~5,700 kWh |
What you're actually paying for
Your total covers panels, mounting rails, the inverter, DC and AC cabling, scaffolding, the electrical work, DNO notification and your MCS certificate. Panels are rarely more than a third of it, which surprises most people.
The rest is installation. Scaffolding and labour take a bigger share than most people expect, which is why a simple two-storey gable roof costs less to fit than a complex roof with dormers, and why installing while scaffolding is already up for roof repairs saves real money. There's more detail in our breakdown of what it costs to install solar panels.
Net cost, after VAT and grants
Solar and battery installations carry 0% VAT until 31 March 2027, after which the rate reverts to 5%. On a £7,000 system that relief is worth £1,400 against the standard 20% rate, and it comes straight off your payback period.
There's no dedicated national solar grant. The Warm Home: Local Grant covers up to £30,000 of energy efficiency work for eligible households in participating councils, and the ECO4 scheme funds solar for some low-income households. Always run your payback maths on the net figure you actually pay, not the headline price.
Cash versus finance
Paying cash means your payback clock starts on day one. Financing at, say, 7.9% over 10 years on a £7,000 system adds roughly £3,000 in interest, which pushes break-even out to around 15 years.
The trade-off is that your monthly repayment may be lower than the electricity bill it replaces, so you're cashflow-positive from month one even though the break-even point sits further out. Neither is wrong. Just be clear which question you're answering.
What affects how long solar panels take to pay back?
Six variables set your break-even point, in rough order of how much they matter:
- What you pay for the system. A 4kW system at £6,300 pays back in 9.4 years. The same system at £9,000 takes 13.4 years. Nothing else on this list has that much leverage.
- How much you use yourself. Every unit you self-consume saves 26.11p. Every unit you export earns around 12p.
- Your export tariff. The spread between a 5p and a 20p SEG rate is worth £342 a year on a 4kW system.
- Roof orientation and shading. East or west costs you around 18% of output against due south.
- Where you live. Hampshire generates roughly 16% more per kWp than the East Midlands.
- Future electricity prices. Every rise makes your own generation more valuable. The cap rose 13% on 1 July 2026 alone.
Quantify each one against your own roof and bills rather than accepting a generic figure. The sections below show you how.
Roof orientation, shading and output
A south-facing roof pitched at 30-40 degrees captures the most energy across a UK year. Move away from south and output falls, though less sharply than most people assume.
| Orientation | Annual output, 4kW | Annual benefit | Payback on £7,000 |
| South | 3,800 kWh | £670 | 10.4 years |
| South East / South West | 3,610 kWh | £637 | 11.0 years |
| East or West | 3,135 kWh | £553 | 12.7 years |
| North | 2,280 kWh | £402 | 17.4 years |
An east-west split roof deserves a mention on its own. You lose peak midday output but gain a broader generation curve, with more in the early morning and evening. For a household that uses electricity at breakfast and dinner rather than lunchtime, an east-west array often self-consumes a higher share than a south-facing one, which claws back part of the loss. We go into this further in do solar panels need to face south?
Shading is the bigger risk. A single chimney, satellite dish or neighbouring tree shading one panel can drag down a whole string on a basic system. Panel-level optimisers or microinverters isolate the affected panel and typically recover most of the loss, for around £300-£600 extra on a domestic array. If your surveyor can't show you a shading analysis across the year, get another quote.
North-facing roofs aren't worth it. We'll tell you that before you pay for a survey.
System size and panel count
Modern domestic panels run 400-500W each, so panel count follows system size directly. A 4kW array is ten 400W panels, a 6kW array is fifteen. Roof space works out at roughly 5-6 m² per kW.
Cost per kWp falls as systems get larger, because scaffolding, labour, the DNO application and the MCS certificate cost much the same whether you fit eight panels or fifteen.
| System size | Typical cost | Cost per kWp | Payback (South East, 40% self-use) |
| 3 kW | £5,750 | £1,917 | 11.4 years |
| 4 kW | £7,000 | £1,750 | 10.4 years |
| 5 kW | £8,500 | £1,700 | 10.1 years |
| 6 kW | £9,750 | £1,625 | 9.7 years |
Oversizing has a real limit, though. Once your array generates far more than you can use, the extra units export at 12p rather than displacing 26.11p imports, so each additional kW earns less than half what the first ones did. Beyond about 6kW on a standard domestic supply you also pass the G98 threshold and need G99 approval from your DNO, which adds cost and time.
The sweet spot for most South East homes is a system sized to your annual consumption, then stretched by 20-30% if the roof allows and your export tariff is decent.
How you use electricity
This is where two identical systems on two identical roofs produce very different answers.
| Your day | Self-consumption | Annual benefit, 4kW | Payback on £7,000 |
| Out 9-5, nobody home | 25% | £590 | 11.9 years |
| Home part of the day | 40% | £670 | 10.4 years |
| Home all day / WFH | 50% | £724 | 9.7 years |
Working from home is worth about two years off your payback compared with an empty house, and it costs nothing to arrange.
EV charging is the single biggest lever available to most households. A car covering 8,000 miles a year needs roughly 2,300 kWh. Charge it on a daytime schedule from your own roof and you displace 2,300 kWh of grid import, worth about £600 a year on its own at current rates. Households that add an EV routinely cut two to three years off payback. See charging your car with solar PV for how the scheduling works in practice.
Heat pumps help in the shoulder seasons, though the overlap with solar is weaker in deep winter when demand peaks and generation bottoms out.
Shifts that cost nothing: run the dishwasher and washing machine on a midday timer, heat your hot water cylinder with a solar diverter rather than gas, and batch the tumble drying into sunny afternoons. A solar diverter costs £200-£400 and typically absorbs 800-1,200 kWh a year that would otherwise export at 12p.
Does battery storage shorten payback?
Not on its own, and this is the part most solar articles get wrong.
A battery does increase self-consumption, from around 40% to 75% or higher. What it doesn't automatically do is shorten your payback, because at current prices the extra electricity it lets you keep is worth less than the battery costs.
Run the numbers on a 5kW system in the South East:
| No battery | With 10kWh battery | |
| Installed cost | £8,500 | £15,000 |
| Self-consumption | 40% | 75% |
| Bill saving | £496 | £930 |
| Export income | £342 | £143 |
| Total annual benefit | £838 | £1,073 |
| Payback | 10.1 years | 14.0 years |
So when does a battery make sense? Three situations, and they're all real.
- You're on a time-of-use tariff. Charge the battery overnight at around 7p and discharge it through the evening peak instead of importing at 26.11p. On 250 cycles a year at 8kWh usable, that arbitrage alone is worth about £382 a year. Add it to the solar benefit and the same 5kW-plus-battery system pays back in 10.3 years rather than 14.
- You use a lot of electricity. The higher your consumption, the more of the stored energy you actually displace at full price. Our own customers with EVs and batteries are seeing 5.5 to 7.8 year paybacks, shown below.
- You want the power to stay on. A battery with backup functionality keeps your lights, fridge and router running through a cut. That's worth something, and it isn't a payback calculation.
If none of those apply, put the money into more panels instead. A battery buys you flexibility. Extra panels buy you generation, and generation is what pays the system off. Our guide to sizing a solar battery covers how to match storage to your evening load.
The Smart Export Guarantee and export income
The Smart Export Guarantee, launched in January 2020, obliges every licensed electricity supplier with 150,000 or more customers to offer a tariff for the surplus electricity you export. You choose your SEG tariff independently, so it needn't come from the supplier you buy your import electricity from. Most households can improve their export rate simply by shopping around.
What you need to qualify:
- An MCS certificate for the installation (or Flexi-Orb equivalent)
- A smart meter capable of half-hourly export readings, so a SMETS2 meter, or a SMETS1 that's been enrolled onto the national network
- A system of 5MW or less
- Your DNO notification completed by the installer
The smart meter is the part that trips people up. Without half-hourly export data no supplier can pay you, and some older SMETS1 meters can't provide it. Confirm yours before you bank on export income in your payback sum. Our guide to applying to the SEG scheme walks through the paperwork.
What the rates look like in August 2026:
| Tariff | Rate | Condition |
| Good Energy Solar Savings Exclusive | 25p/kWh | Must have bought the system from Good Energy, 12-month term |
| So Energy So Bright Export | 20p/kWh | Highest flat rate open to new customers |
| EDF, E.ON Next and similar | 15-18p/kWh | Usually tied to their own installations |
| Typical market rate | 12-13p/kWh | What most households actually get |
What the rate is worth on a 4kW system:
| SEG rate | Annual benefit | Payback on £7,000 |
| 5p | £511 | 13.7 years |
| 12p | £670 | 10.4 years |
| 15p | £739 | 9.5 years |
| 20p | £853 | 8.2 years |
When exporting beats storing: if your SEG rate is above roughly 15p and your evening consumption is modest, exporting the surplus outperforms buying a battery to store it. Below 10p, storage starts to look better, provided you actually use what you store.
Worked examples
All examples use the Ofgem price cap for 1 July to 30 September 2026, so 26.11p/kWh import. Export is priced at 12p/kWh unless stated. Your own figures will differ with your usage, generation and energy costs.
A 4kW system with no battery
A three-bedroom semi near Fareham. South-facing roof, no shading, two adults with one working from home two days a week.
| System | 4kW, 10 x 400W panels |
| Net cost after 0% VAT | £7,000 |
| Annual generation | 3,800 kWh |
| Self-consumed (40%) | 1,520 kWh x 26.11p = £396.87 |
| Exported (60%) | 2,280 kWh x 12p = £273.60 |
| Total annual benefit | £670.47 |
| Payback | £7,000 ÷ £670.47 = 10.4 years |
| Year | Net position |
| 1 | -£6,330 |
| 5 | -£3,648 |
| 10 | -£295 |
| 11 | +£375 (break even) |
| 12 | +£46 (inverter replaced) |
| 15 | +£2,057 |
| 20 | +£5,409 |
| 25 | +£8,762 |
A 5kW system with battery storage
The same house, upgraded: 5kW array, 10kWh battery, an EV on the drive and a time-of-use import and export tariff.
| Without battery | With battery and smart tariff | |
| Installed cost | £8,500 | £15,000 |
| Generation | 4,750 kWh | 4,750 kWh |
| Self-consumption | 40% | 80% |
| Bill saving | £496 | £992 |
| Export income | £342 | £114 |
| Overnight arbitrage | £0 | £382 |
| Total annual benefit | £838 | £1,488 |
| Payback | 10.1 years | 10.1 years |
South East versus East Midlands
| South East | East Midlands | |
| Yield per kWp | 950 kWh | 820 kWh |
| 4kW annual generation | 3,800 kWh | 3,280 kWh |
| Annual benefit | £670 | £579 |
| Payback on £7,000 | 10.4 years | 12.1 years |
What our own customers are seeing
Modelled figures use market averages. These are real installations, real bills and real payback maths from Hampshire homes, and every one reflects that household's own usage and tariff.
4.2kW solar with a 10.5kWh battery, four-bed detached, installed April 2025. Fourteen panels, SolarEdge SE4000H inverter. Across the first eight months the household paid £64 in total energy bills and held £180 of credit on the account. Annual saving £1,400 against a £7,700 system: 5.5 years.
Solar and battery retrofit, 85% bill reduction. From £2,136 a year to £316. Actual energy consumption now costs £4.66 a month. Even in January, grid imports ran at just 8-12 kWh a day. On a system of around £10,000 saving £1,820 a year: 5.5 years.
Solar only, genuine Octopus bills compared. April 2022 before, April 2025 after. Grid imports fell 61%, from 11.68 kWh a day to 4.60. Export income of £24 a month. Net annual saving £1,023 on an £8,000 system: 7.8 years.
Every one of these beats the ten-year national average, for two reasons. These households use a lot of electricity, so more of what they generate displaces full-price imports. And they didn't pay market-average prices.
How to shorten your payback
Ranked by how much each is worth, not by how easy it is.
1. Get three MCS-certified quotes. The spread between quotes for identical systems routinely runs £2,000 or more. On a 4kW system that's three years of payback, available for the cost of two extra phone calls. Check every installer at mcscertified.com.
2. Move your consumption into daylight. Timers on the dishwasher and washing machine, a solar diverter for hot water, daytime EV charging. Going from 25% to 50% self-consumption is worth 2.2 years on a 4kW system and costs nothing beyond the diverter.
3. Review your export tariff every year. Moving from 12p to 16p is worth £91 a year on a 4kW system and takes one switching form.
4. Install before 31 March 2027. The 0% VAT rate ends then and reverts to 5%. On a £7,000 system that's £350.
5. Size the battery to your evening load, not to the roof. A 5kWh battery that cycles fully every day beats a 15kWh battery that sits half empty. Oversized storage is the most common way to wreck an otherwise good payback.
6. Check your grant eligibility first. The Warm Home: Local Grant and ECO4 can cover a substantial share of the cost for eligible households, and a grant-funded system changes the arithmetic completely.
After break even: the next 15 years
Your break-even point is the moment cumulative savings overtake what you spent. For the 4kW example above that falls in year 11. From then on the electricity is effectively free for another 14 to 19 years of warranted panel life, and on that example the net position reaches +£8,762 by year 25.
Budget for one inverter replacement at £800-£1,200 around year 12. That's already in the figures above, and it's the only significant maintenance cost most systems incur.
Property value. Peer-reviewed research from the Urban Big Data Centre at the University of Glasgow found a premium of roughly 6-7% for homes with solar panels, though any uplift varies by property and local market. Buyers pay for lower running costs and a better EPC rating, and MCS-certified installations transfer cleanly on sale. Treat it as a bonus rather than part of the payback sum. We look at the study in more detail in how solar panels affect property value.
Carbon footprint. A typical home installation cuts around one tonne of CO2 a year, equivalent to driving 3,600 miles. It won't appear on your payback spreadsheet, but it's the reason a lot of people start looking at renewable energy in the first place.
The inflation hedge is the part people undervalue. The price cap rose 13% on 1 July 2026. Every rise like that makes the electricity you generate yourself more valuable, and none of them touch the units you produce on your own roof. One of our customers paid £1,041 for electricity in 2021 and £880 in 2025, over a period when grid prices roughly doubled.
How CRG Direct sizes and installs solar
We survey and install across Hampshire, Surrey, West Sussex and the South Coast, and we'd rather talk you out of a system than sell you one that won't pay back.
Free survey and honest sizing. We model your actual consumption from your bills, run a year-round shading analysis on your roof, and size the array to what you'll use rather than to what fits. If your roof is wrong for solar, we say so at survey stage rather than in month six.
MCS certified, HIES guaranteed, NICEIC approved. Your MCS certificate is what unlocks SEG payments, so it isn't optional paperwork. Installations start from £6,300 including the MCS certificate, mounting kit and HIES insurance-backed guarantee. Panel warranties run to 25 years, with inverter warranties extendable to 15.
Retrofit and grant support. We add battery storage to existing arrays, replace ageing inverters, and handle Warm Home: Local Grant and ECO4 applications for eligible households, along with all DNO G98 and G99 notifications.
Get a free quote · Try the solar payback calculator · Call 0333 253 3531
"From start to finish we found CRG helpful, professional and the workmanship excellent." Iain, CRG solar customer
FAQs
How long do solar panels take to pay back? Eight to eleven years for most UK homes. The Energy Saving Trust puts London at 9 years and Stirling at 12, using July 2026 fuel prices. In the South East, a well-priced 4kW system on a south-facing roof pays back in around 9 to 10 years, and high-consumption households with EVs regularly beat 7. Commercial installations tend to land between 4 and 7 years, because businesses use most of their generation on site during daylight hours.
Do batteries always improve payback? No, and this catches a lot of people out. A £6,500 battery typically adds around £235 a year of benefit on a standard tariff, which is a 27-year payback on a unit warranted for ten. Batteries earn their keep when you pair one with a time-of-use tariff and charge it overnight at around 7p to avoid importing at 26.11p, or when your consumption is high enough that you genuinely use everything you store. Buy one for the bill reduction, the smart-tariff arbitrage or the backup power, not on the assumption that it shortens payback by itself.
Do solar panels work in cloudy UK weather? Yes. Panels respond to daylight rather than direct sunshine, so they generate on overcast days at roughly 15-25% of peak output. UK systems are specified around this. A 4kW array in Hampshire produces about 3,800 kWh a year across genuine British weather, with July generating five to six times what December does. There's more in do solar panels work in cloudy weather.
Should I choose a grid-tied system or a hybrid? Choose grid-tied if you have no battery plans, a decent export tariff and no particular worry about power cuts. It's cheaper and simpler. Choose a hybrid inverter if you intend to add storage later, want backup power during outages, or plan to run a time-of-use tariff. The hybrid costs £300-£800 more up front and saves you replacing the inverter when you add a battery, so if storage is realistic within five years, fit the hybrid now.
How much do solar panels cost to install? The Energy Saving Trust puts the UK average at around £7,600 for a 4.5kWp system. Across the South East we typically see £6,000-£8,000 for 4kW and £8,500-£11,000 for 6kW, including scaffolding, inverter, electrical work, DNO notification and MCS certificate, at 0% VAT until 31 March 2027.
How much can solar panels save on electricity bills? A 4kW system in the South East generates about 3,800 kWh a year. At 40% self-consumption that's £397 off your bill plus £274 of export income, so £670 a year in total, depending on your usage, generation and energy costs. Push self-consumption to 50% with daytime appliance use and a solar diverter and the total rises to £724. Households with an EV and a battery on a smart tariff see £1,400 or more.
Are there any grants for solar panels? There's no dedicated national solar grant. The Warm Home: Local Grant covers up to £30,000 of energy efficiency measures for eligible households in participating council areas, and ECO4 funds solar for some low-income households. Solar also carries 0% VAT until 31 March 2027, worth £1,400 on a £7,000 system against the standard rate.
How many solar panels do I need? Divide your target system size by panel wattage. Modern panels run 400-500W, so a 4kW system is ten 400W panels and needs 20-24 m² of roof. As a starting point, take your annual consumption in kWh and divide by 950, which gives you the kWp figure for a South East roof. See how many solar panels do I need for a fuller method.
What happens after the panels pay for themselves? The electricity is free for the remaining panel life, typically another 14 to 19 years on a 25-year warranty and often longer. Budget one inverter replacement at £800-£1,200 around year 12. On the 4kW example in this guide, the net position reaches +£8,762 by year 25, and more if electricity prices keep rising.
Sources
- Ofgem, energy price cap unit rates and standing charges: 26.11p/kWh electricity, 1 July to 30 September 2026, up 13% on the April cap
- Energy Saving Trust, solar panels: costs, savings and benefits: average 4.5 kWp system at £7,600, payback by location, battery costs £5,000-£8,000
- Ofgem, Smart Export Guarantee (SEG)
- HMRC, VAT Notice 708/6: energy-saving materials: 0% rate to 31 March 2027
- Microgeneration Certification Scheme, find an installer
- Asproudis, Gedikli, Talavera and Yilmaz, "Returns to solar panels in the housing market: a meta learner approach", Energy Economics, via the Urban Big Data Centre: 6.1%-7.1% property premium
- CRG Direct installation and monitoring data, Hampshire, 2022-2026