Solar panel savings calculator — how much will solar save you?
Use our lookup table to estimate annual solar savings for your region and system size. Based on 2026 UK electricity prices, real UK regional yield data, and typical self-consumption rates — with and without a home battery.
Annual savings by system size and region
| System size | Panels | Annual generation | South England | Midlands | North England / Scotland | South + battery | Payback (no battery) |
|---|---|---|---|---|---|---|---|
| 3 kWp | 6–8 | 2,550–3,150 kWh/yr | £570–£700 | £510–£630 | £450–£570 | £670–£820 | 10–15 years |
| 4 kWp | 8–10 | 3,400–4,200 kWh/yr | £760–£940 | £680–£840 | £600–£740 | £890–£1,100 | 9–14 years |
| 5 kWp | 10–13 | 4,250–5,250 kWh/yr | £950–£1,175 | £850–£1,050 | £750–£925 | £1,110–£1,375 | 9–13 years |
| 6 kWp | 12–15 | 5,100–6,300 kWh/yr | £1,140–£1,410 | £1,020–£1,260 | £900–£1,110 | £1,335–£1,650 | 8–13 years |
| 10 kWp | 20–25 | 8,500–10,500 kWh/yr | £1,900–£2,350 | £1,700–£2,100 | £1,500–£1,850 | £2,225–£2,750 | 8–12 years |
Savings include: bill savings from self-consumed solar + Smart Export Guarantee income on exported surplus. Figures rounded to nearest £10. Install costs vary: 3kWp ~£5,000–£7,500; 4kWp ~£6,000–£9,000; 6kWp ~£8,000–£13,000. System costs have fallen ~20% since 2022.
How to use this table
1. Find your region. South England (roughly south of Birmingham) gets approximately 10% more solar energy than the Midlands, and 20% more than northern Scotland. The difference in annual savings is roughly £100–£200 for a 4kWp system.
2. Choose a system size. A typical 3-bedroom semi uses 3,000–4,000 kWh/year. A 4kWp system will produce roughly that amount in the Midlands — so a well-matched system can cover a significant proportion of your electricity use.
3. Consider a battery.The 'South + battery' column shows the uplift from adding a 5–10 kWh battery. In the Midlands and North, add approximately £100–£150 for the battery uplift vs the no-battery South England figure to estimate your savings.
4. Get a site-specific quote. These figures are estimates. An MCS-certified installer will survey your roof, measure shading with specialist tools, calculate your actual heat loss or energy use, and give you a precise payback forecast.
Solar savings calculator FAQs
How accurate are these solar savings estimates?
These are ballpark estimates based on UK average electricity prices, regional solar yield data, and typical self-consumption patterns. Your actual savings depend on: your exact electricity unit rate, your home's roof orientation and shading, how much electricity you use during the day, and whether you have a Smart Export Guarantee tariff. A proper site survey from an MCS-certified installer will give you a property-specific estimate.
What self-consumption rate should I expect?
A typical UK home without a battery self-consumes 30–45% of solar generation. With a home battery, self-consumption rises to 55–75%. Higher self-consumption means more savings, since you're displacing expensive imported electricity (24p/kWh) rather than exporting at the SEG rate (typically 4–24p/kWh). If you work from home or have high daytime loads (heat pump, EV charger), your self-consumption will be towards the higher end.
How does a home battery improve solar savings?
A battery stores surplus solar energy generated midday for use in the evenings, when the sun has set but household demand is high. Instead of exporting at 4–24p/kWh, you use the stored electricity at home — displacing grid imports at 24p/kWh. The difference (approximately 0–20p/kWh) is your extra saving. A 5kWh battery typically adds £150–£300/year in savings for a 4kWp solar system.
What is the payback period for solar panels in the UK?
For a typical 4kWp system costing £6,000–£9,000 installed, the payback period is 9–14 years with no battery, or 10–16 years with a combined solar-plus-battery system (factoring in battery cost). Payback periods have shortened significantly since 2021 due to higher electricity prices. In 2022–2024, many homeowners saw paybacks of 7–10 years.
Will rising electricity prices increase my solar savings?
Yes. Solar savings scale directly with the electricity unit rate. If unit rates rise from 24p to 30p/kWh, your annual saving from a 4kWp system increases by roughly £100–£150/year. This is one of the key financial arguments for solar as a hedge against future energy price increases.
Does my SEG rate affect the savings estimate?
Yes. If you're on Octopus SEG (~24p/kWh for exports) rather than a lower-rate supplier (3–6p/kWh), your export earnings are significantly higher. The estimates in the table above use an average SEG rate of ~15p/kWh. If you optimise for the best SEG tariff, your actual savings could be 10–20% higher than these estimates.
Get a precise solar savings estimate
An MCS-certified installer will survey your roof, calculate real yield using SAP/PVGIS data, and give you a site-specific payback forecast. Free quotes, no commitment.