How much does a 3kW solar system cost?
Priced June 2026
A 3kW solar system costs £5,000–£6,500 installed — about 7 panels, generating ~2,550 kWh a year.
Best suited to 1–2 bed home, lower usage. Payback is typically 8–12 years.
| Typical installed cost | £5,000–£6,500 |
| Number of panels | ~7 panels |
| Annual generation | ~2,550 kWh |
| Typical payback | 8–12 years |
| Best suited to | 1–2 bed home, lower usage |
| Roughly per kW | £1,833/kW |
A 3kW system sits at the smaller end of typical UK home installs. The price covers the 7 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 3kW 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 3kW solar system cost in the UK?
A 3kW solar system typically costs £5,000–£6,500 installed in 2026 (panels only, 0% VAT), using around 7 panels — roughly £1,833 per kW.
How much electricity does a 3kW system generate?
A 3kW system generates about 2,550 kWh a year in the UK (south-facing, unshaded), enough for 1–2 bed home, lower usage.
How long does a 3kW 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.