Solar panels in Britain. Sounds like a joke, right? But actually, the numbers work better than you’d think. Panels have got much cheaper, electricity prices are still high after the energy crisis, and there’s no VAT on residential solar until at least 2027. For most homeowners, the answer is a cautious yes — but the payback and returns vary a lot depending on your setup.
What Do Solar Panels Cost in 2025?
A typical residential system in the UK:
- 3kW (8–10 panels): £4,000–£5,500 — good for a small house or a couple
- 4kW (10–12 panels): £5,500–£7,500 — the most common residential size
- 6kW (15–18 panels): £7,500–£10,000 — for bigger families or EV owners
Prices have dropped about 50% since 2015. Adding battery storage is another £2,500–£5,000 depending on capacity (5–13 kWh). And remember: 0% VAT on residential solar panels until at least March 2027. That alone saves you 20%.
How Much Will You Save?
A 4kW system in southern England typically generates 3,400–3,800 kWh/year. Up in Scotland, expect 2,800–3,200 kWh. Average UK household consumption is about 2,900 kWh/year.
The key factor is how much of what you generate you actually use (rather than exporting to the grid). Without a battery, typical self-consumption is 30–50%. With a battery, 60–80%.
At roughly 24p/kWh for electricity right now:
- Without battery: Save about £400–£550/year
- With battery: Save about £600–£800/year
These figures assume you’re home during the day or can shift your usage (washing machine, dishwasher, EV charging) to peak generation hours.
The Smart Export Guarantee
Surplus electricity you don’t use goes to the grid. Under the Smart Export Guarantee, your energy supplier must pay you for it. Current rates range from 3p to 15p per kWh depending on the supplier and tariff. Some offer “agile” export tariffs that pay more during peak demand. Shopping around for the best SEG rate is worth doing — over 25 years, the difference adds up considerably.
Payback Period
Based on current prices and savings:
- Panels only (4kW): 9–13 years
- Panels + battery (4kW + 5kWh): 11–16 years
Panels are warranted for 25–30 years and typically keep 80% output at 25 years. After payback, everything you save is basically profit. Over the full lifespan, a 4kW system can save £10,000–£15,000 in today’s money. That’s a decent return on a £6,000 investment.
What Affects Your Return
- Roof orientation: South-facing is ideal. East or west cuts output by 15–20%. North-facing? Generally not worth it.
- Roof pitch: 30–40 degrees is optimal for the UK
- Shading: Trees, chimneys, and neighbouring buildings can seriously reduce output
- Location: Southern England gets 10–20% more sun than Scotland
- Electricity tariff: The higher your unit rate, the more you save by self-consuming
- Self-consumption: Home workers and EV owners benefit most because they use electricity during the day when panels are generating
Impact on EPC and Property Value
Solar panels can bump your EPC rating by 10–20+ points, potentially moving you up a band. Research suggests homes with solar sell for 1–3% more, though it varies by area. For landlords, the EPC improvement helps meet Minimum Energy Efficiency Standards.
Calculate Your Solar ROI
Our free solar ROI calculator estimates your annual savings, payback period, and 25-year return based on location, roof orientation, electricity usage, and whether you’re adding a battery. Worth running before getting quotes.