Can solar fully power a heat pump?

Annually yes — a 6kW system generates 5,600+ kWh/yr, enough to offset 4,000-6,000 kWh heat pump use. But not in real-time in winter — you'll draw from the grid in winter and over-generate in summer.

Should I install solar or heat pump first?

Solar first — it's cheaper, simpler, and starts saving immediately. Add the heat pump when your gas boiler needs replacing. The BUS grant (£7,500) makes heat pumps much more affordable.

What battery size for solar + heat pump?

10-13.5kWh recommended. This stores enough surplus solar to run the heat pump for 2-3 hours in the evening, significantly boosting self-consumption.

Do I need a bigger solar system with a heat pump?

Yes — if planning a heat pump, size your solar at 5-6kW minimum (vs 3-4kW without). The extra 2kW costs £1,500-£2,000 but saves significantly more over 25 years.

Sizing Solar for a Heat Pump

By Home Solar Guide Team|Updated 18 March 2026|educational

Independently written | Evidence-based | Sources cited

Solar heat pump sizing — A heat pump needs 4,000-6,000 kWh/yr — size your solar to match.

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How many solar panels do I need for a heat pump?

A typical UK air source heat pump (ASHP) uses 4,000-6,000 kWh of electricity per year to heat an average 3-bed home. To offset this with solar you need: 10-15 panels (4-6kW system). But timing matters — heat pumps run hardest in winter when solar output is lowest. Realistic solar offset: 30-40% of heat pump electricity directly, rising to 60-70% with a battery. Annual savings vs gas boiler: £600-£1,000/yr (solar + heat pump combined). Best setup: 6kW solar + 10kWh battery + ASHP. Total cost: £22,000-£27,000 (minus £7,500 BUS grant). Payback: 10-14 years.

Frequently Asked Questions

Related: Home Heating Systems

Solar panels are most powerful when combined with an efficient heating system. Heat pumps use solar-generated electricity to heat your home at 300-400% efficiency — making them the ideal partner for solar.

air source heat pump guide

Learn more about how air source heat pumps work alongside solar panels.

heat pump grants and the BUS scheme

The Boiler Upgrade Scheme offers £7,500 towards heat pump installation.

comparing heat pumps to gas boilers

When your boiler needs replacing, a heat pump powered by solar is the most efficient option.

From our sister site Home Heat Pump Guide