The quick answer
Solar panels and a heat pump solve different problems — but together they're the strongest route to near-zero energy bills.
- Solar panels generate electricity and cut your electricity bill.
- A heat pump replaces your boiler and cuts your heating bill (and carbon).
A heat pump runs on electricity — and solar makes electricity. So panels directly lower a heat pump's running cost, especially in spring and autumn. Add a battery, and you can run your heating on stored daytime solar in the evening.
The honest framing: don't fit a heat pump expecting huge savings over mains gas — fit it to get off fossil fuel. The strong financial case is solar first (predictable payback), then a heat pump when your boiler is due for replacement.
What each one actually does
| Solar PV | Air source heat pump | |
|---|---|---|
| Does | Generates electricity | Replaces your heating system |
| Typical cost | £5,000–£8,000 (4kW) | £8,000–£14,000 |
| Grant | 0% VAT (to Mar 2027) | £7,500 (BUS) |
| Net cost | £5,000–£8,000 | £2,000–£6,500 |
| Saves | £400–£700/yr on electricity | Biggest vs oil/LPG/electric |
| Payback | 8–12 years | Depends on fuel replaced |
| Lifespan | 25+ years | 15–20 years |
The £7,500 Boiler Upgrade Scheme
The Boiler Upgrade Scheme (BUS) pays £7,500 towards an air-source or ground-source heat pump in England and Wales. Key facts:
- No income test — open to any homeowner, unlike ECO4.
- £9,000 top-up — off-gas-grid homes heated by oil or LPG get a temporary £1,500 uplift (21 July 2026 to 31 March 2027).
- No EPC barrier — the insulation requirement was scrapped in April 2026.
- Must be MCS-installed — and your installer applies for the grant on your behalf.
The grant is for the heat pump only. It does not cover solar panels, battery storage, or radiator upgrades. Solar is funded separately (0% VAT, or ECO4/Warm Homes if income-eligible).
Real costs compared
Combined, here's the realistic picture for a full low-carbon retrofit:
| Item | Cost before grant | Net cost |
|---|---|---|
| Solar PV (4kW) | £5,000–£8,000 | £5,000–£8,000 (0% VAT) |
| Air source heat pump | £8,000–£14,000 | £2,000–£6,500 (−£7,500) |
| Battery (optional) | £4,000–£6,000 | £4,000–£6,000 |
| Combined total | £17,000–£28,000 | £11,000–£20,500 |
Why the combination works
A heat pump delivers 3–4 units of heat per unit of electricity (300–400% efficiency). Pair it with solar and the maths becomes compelling:
- Daytime heating on free solar — in spring and autumn, your panels cover much of the heat pump's daytime draw.
- Battery for evening heating — store daytime solar to run the heat pump after dark.
- Near-zero bills — a well-insulated home with both can cut energy bills by up to 80%.
A 4kW solar array + an air source heat pump is one of the most common retrofit pairings for households trying to eliminate gas. Heat the house during the day on solar, export the summer surplus, and you've decoupled from the grid for most of the year.
Who should get both
- Off the gas grid (oil/LPG/electric) — the strongest case: heat pump slashes heating cost, solar cuts the electricity to run it.
- Boiler near end of life — replace it with a heat pump (grant offsets most of the premium).
- Cutting carbon is a priority — this is the closest a retrofit gets to net-zero.
On mains gas with a healthy boiler, the financial case is weaker — don't rip out a working boiler expecting big savings.
Solar first or heat pump first?
For most gas-heated homes, the smart sequence is:
- Solar first — fastest, most predictable payback (8–12 years), lower electricity bill immediately.
- Heat pump later — when the boiler is due for replacement and the £7,500 grant is on the table.
This way you start saving immediately and time the heat pump to when you'd be replacing the boiler anyway.
Model your solar savings first
Solar is the first step — see how much a system saves you before adding a heat pump.
Calculate my savings →FAQ
Will a heat pump save me money over gas?
Not always. Electricity costs more per kWh than gas, but a heat pump delivers 3–4 units of heat per unit of electricity, so running costs land close to mains gas for a well-insulated home. The big savings are for homes on oil, LPG or electric heating.
Can I run a heat pump entirely on solar?
In summer, yes — solar can cover most of the heat pump's modest hot-water load. In winter, no — short days and cold weather mean you'll still import electricity. That's why the combination works best with a battery and a good tariff.
Is the £7,500 grant means-tested?
No. The Boiler Upgrade Scheme is open to any homeowner in England and Wales, regardless of income. This is the key difference from ECO4, which is income-tested.
Sources: GOV.UK Boiler Upgrade Scheme, Ofgem, Energy Saving Trust, industry quote data (2026). Figures verified August 2026. Grant levels and scheme rules change — confirm with an MCS-certified installer.
Disclaimer: this guide is for general information only and is not financial advice. Heat pump suitability depends on your home's insulation and heating system.