How much does a 4kW solar system cost?
Priced June 2026
A 4kW solar system costs £6,000–£8,000 installed — about 10 panels, generating ~3,400 kWh a year.
Best suited to 2–3 bed home (uk average). Payback is typically 8–12 years.
| Typical installed cost | £6,000–£8,000 |
| Number of panels | ~10 panels |
| Annual generation | ~3,400 kWh |
| Typical payback | 8–12 years |
| Best suited to | 2–3 bed home (UK average) |
| Roughly per kW | £1,750/kW |
A 4kW system sits at the smaller end of typical UK home installs. The price covers the 10 panels, the inverter, mounting and scaffolding, certified labour and MCS certification — at 0% VAT until 31 March 2027. Here's how it compares to other system sizes:
| System | Low | Typical | High |
|---|---|---|---|
| 3kW | £5,000 | £5,500 | £6,500 |
| 4kW | £6,000 | £7,000 | £8,000 |
| 5kW | £7,500 | £8,500 | £9,800 |
| 6kW | £9,000 | £10,000 | £11,500 |
| 8kW | £11,000 | £12,500 | £14,500 |
| 10kW | £13,000 | £15,000 | £17,000 |
Whether a 4kW system is right for you depends less on your property type than on how much electricity you actually use. Put your own usage into the free calculator to see your cost, saving and payback, or see the full cost-of-solar breakdown.
Frequently asked questions
How much does a 4kW solar system cost in the UK?
A 4kW solar system typically costs £6,000–£8,000 installed in 2026 (panels only, 0% VAT), using around 10 panels — roughly £1,750 per kW.
How much electricity does a 4kW system generate?
A 4kW system generates about 3,400 kWh a year in the UK (south-facing, unshaded), enough for 2–3 bed home (uk average).
How long does a 4kW system take to pay back?
Typically 8–12 years on panels alone, depending on how much generation you use yourself, your tariff and your region.