0% VAT applies until 31 March 2027ly. A typical 4.5kWp system costs £6,500–£9,000 installed. Eligible households may qualify for free solar through the Warm Homes: Local Grant. Here’s the full cost breakdown.
Solar panel prices have fallen significantly over the past decade. In 2026, a typical 4.5kWp system for a 3-bed semi-detached home costs £6,500–£9,000 installed, before considering any grants or subsidies. 0% VAT runs until 31 March 2027 under current rulesly applied to domestic solar installations.
| System size | Panels | Typical cost | Annual generation | Annual saving* | Payback |
|---|---|---|---|---|---|
| 2.5 kWp | 6 panels | £4,000–£6,000 | ~2,250 kWh | £350–£500 | 9–14yr |
| 3 kWp | 7 panels | £5,000–£7,000 | ~2,700 kWh | £420–£600 | 9–13yr |
| 4.5 kWp (most common) | 10 panels | £6,500–£9,000 | ~4,050 kWh | £600–£900 | 8–12yr |
| 6 kWp | 14 panels | £8,000–£11,000 | ~5,400 kWh | £750–£1,100 | 8–12yr |
| 9 kWp | 20 panels | £11,000–£16,000 | ~8,100 kWh | £900–£1,400 | 9–13yr |
*Savings estimate based on Energy Saving Trust benchmarks and Ofgem Q3 2026 price cap (£1,862/year). Actual savings depend on orientation, shading, self-consumption rate, SEG payments and tariff. Individual quotes will vary.
Savings caveat: EST estimates direct bill savings at £190–£330/year for a 4.5kWp system before SEG income. Combined savings including Smart Export Guarantee payments vary significantly by household and tariff.
South-facing pitched roofs achieve the highest output. East-west split installations are increasingly common and can actually outperform south-only on self-consumption.
Premium monocrystalline PERC or TOPCon panels cost more but achieve higher efficiency per square metre — important on limited roof space.
Adding battery storage typically costs an additional £2,500–£6,000. It significantly increases self-consumption and can be funded through WH:LG or the Warm Homes Loan Scheme.
Yes, for most south or east/west facing properties with adequate roof space. The Ofgem price cap remains elevated, making self-generated electricity more valuable. Payback periods of 8–13 years are typical for private installation, and funded solar through WH:LG has immediate payback for eligible households.
Energy Saving Trust estimates direct bill savings of £190–£330/year for a typical 4.5kWp system. Combined savings including SEG payments and reduced imports if you shift consumption to solar generation hours can be significantly higher.
The SEG requires licensed electricity suppliers to pay homeowners for electricity exported to the grid from solar panels. Rates vary — Octopus Energy, Ovo and others offer competitive rates. Check the Ofgem comparison on the Gov.uk website.