Solar ROI Calculator UK

Estimate solar panel payback, battery savings, export income and long-term investment returns for your UK home.

Calculate the real return from solar panels and battery storage before speaking to installers. Start with a quick representative estimate, then personalise the assumptions after sign-up.

Average projected profit£20,958

20-year solar + battery projection

Average payback time11.3 Years

Typical solar + battery installation

Average UK electricity bill£1,265

Per year, before any upgrades

Profile confidence0%

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Quick estimate

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Enter a few key details to get an instant returns estimate.

Representative estimate

Compare solar, storage and combined investment paths.

Baseline spend without upgrades is £37,662 over 20 years.

Decision summary

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Add the property basics to build your initial quote. This first pass can reach up to 50% confidence before a more tailored quote is unlocked.

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Solar + battery looks strongest

Your initial quote points to solar + battery as the best investment option based on your details when modelled with our assumptions.

Projected net profit£20,958

Estimated ROI162%

Based on a 20-year horizon.

Estimate confidence0%

To increase your estimate accuracy, create a personalised quote with tailored usage, roof, installation and household details.

Edit Inputs Our assumptions

Solar only

Representative estimate

Projected net profit£17,379

Payback: 8.7 yrs
Annual benefit: £825
Upfront cost: £7,200
Generation: 3,880.1 kWh

1,872.2 kWh self-consumed, 2,008 kWh exported.

Sensitivity range: £13,556 to £20,507.

How this scenario is calculated

Annual consumption uses electricity-consumption-v1-manual-seed-2026-05 at 3,800 kWh/year (good directional confidence).
Generation lookup uses UK Average at 907 kWh per kWp per year for a south-west roof.
Average semi-detached install size assumed at 4.6 kWp across 23 m2 of roof area.
Solar cost model uses £2,100 fixed plus £1,100 per kWp for semi-detached homes.
Energy prices assumed to rise by 4% per year.
Standing charge held constant at £201 per year.
Self-consumption estimated at 48% based on occupancy, day usage and storage.

Battery only

Representative estimate

Projected net profit£275

Payback: 28.4 yrs
Annual benefit: £201
Upfront cost: £5,700
Generation: 0 kWh

0 kWh self-consumed, 0 kWh exported.

Sensitivity range: £214 to £324.

How this scenario is calculated

Annual consumption uses electricity-consumption-v1-manual-seed-2026-05 at 3,800 kWh/year (good directional confidence).
Generation lookup uses UK Average at 907 kWh per kWp per year for a south-west roof.
Average semi-detached install size assumed at 4.6 kWp across 23 m2 of roof area.
Solar cost model uses £2,100 fixed plus £1,100 per kWp for semi-detached homes.
Energy prices assumed to rise by 4% per year.
Standing charge held constant at £201 per year.
Battery-only value estimated from off-peak charging arbitrage against the import tariff.

Solar + battery

Best fit today

Representative estimate

Projected net profit£20,958

Payback: 11.3 yrs
Annual benefit: £1,137
Upfront cost: £12,900
Generation: 3,880.1 kWh

2,725.8 kWh self-consumed, 1,154.3 kWh exported.

Sensitivity range: £16,347 to £24,731.

How this scenario is calculated

Annual consumption uses electricity-consumption-v1-manual-seed-2026-05 at 3,800 kWh/year (good directional confidence).
Generation lookup uses UK Average at 907 kWh per kWp per year for a south-west roof.
Average semi-detached install size assumed at 4.6 kWp across 23 m2 of roof area.
Solar cost model uses £2,100 fixed plus £1,100 per kWp for semi-detached homes.
Energy prices assumed to rise by 4% per year.
Standing charge held constant at £201 per year.
Self-consumption estimated at 70% based on occupancy, day usage and storage.

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How this is calculated

Assumptions used for this estimate

Electricity model: Representative estimate
Estimated annual use: 3,800 kWh
Model range: 2,774-5,016 kWh
Monthly shape: standard-electric
Solar system: 4.6 kW
Solar cost: £7,200
Battery: 8.3 kWh
Battery cost: £5,700
Import tariff: 28p/kWh
Export tariff: 15p/kWh
Daytime use: 45%
Energy inflation: 4%