A 4-bedroom home typically uses 4,500–5,000kWh of electricity a year. Here is what size solar system you need, what it costs, and how much you could save.
A typical 4-bedroom home uses 4,500–5,000kWh per year. Most installers recommend a 4–5.4kWp system — that is 12–16 solar panels at the typical 400–430W per panel currently available.
| System | Panels (400W) | Annual gen. | Cost installed | Best for |
|---|---|---|---|---|
| 4kWp | 10 | ~3,800kWh/yr | £7,000–£9,500 | Average 4-bed, good south-facing roof |
| 5kWp | 13 | ~4,750kWh/yr | £8,500–£11,000 | Larger 4-bed or east/west split |
| 6kWp | 15 | ~5,700kWh/yr | £10,000–£13,000 | High usage / EV / heat pump |
| + 10kWh battery | — | — | +£4,500–£6,500 | Maximise self-consumption |
With a 10kWh battery, total savings typically rise to £900–£1,100 per year as self-consumption increases from ~30% to ~80%.
Typically 12–16 panels (4–5.4kWp) for a 4-bed home using 4,500–5,000kWh per year. The exact number depends on panel wattage and available roof space.
A 4kWp system costs £7,000–£9,500 installed. A 5–6kWp system costs £9,000–£13,000. Adding a 10kWh battery adds approximately £4,500–£6,500.
Yes. Warm Homes: Local Grant can fund solar panels for eligible households — EPC D or below is typically required. Solar PV was the most common WH:LG measure at 38% of all reported installations to end-July 2026.