Solar Panels with a Heat Pump: The Ultimate Combination

A heat pump uses electricity to produce heat. Solar panels generate free electricity. The combination means your heating can be partially or wholly powered by the sun.

On a sunny spring day, a 4 kWp solar array can generate 15–20 kWh of electricity. Your heat pump might consume 5–8 kWh for heating and hot water. The surplus goes to the grid (earning you SEG payments) or into a battery for the evening.

Over a year, solar can realistically cover 30–50% of your heat pump’s electricity consumption, depending on system size and battery storage. This slashes your heating costs from an already-low base.

The real magic happens with smart controls. By scheduling your heat pump to run during peak solar generation hours (typically 10 am – 3 pm), you can maximise the use of free solar electricity.

Modern heat pumps and smart thermostats can be programmed to pre-heat your home and top up your hot water cylinder when the sun is shining, using thermal mass as a form of energy storage. Your home stays warm into the evening without needing grid electricity.

With a battery, this becomes even more effective — excess solar charges the battery, which then powers the heat pump in the early evening when electricity is most expensive.

When designing a combined system, we consider:

• Your heat pump’s annual electricity consumption — Typically 3,000–6,000 kWh for a well-insulated home. • Your other electricity usage — Lights, appliances, cooking, EV charging. • Roof size and orientation — South-facing is ideal, but east-west splits work well too. • Battery capacity — Sized to bridge the gap between solar generation and evening usage.

A common configuration is a 5–6 kWp solar array with a 10 kWh battery alongside a 7–12 kW heat pump. This gives most families near-complete energy independence during the warmer months and significant savings year-round.

A combined solar + heat pump system typically costs £18,000–£28,000 before the BUS grant. After the £7,500–£9,000 grant and with 0% VAT on both, you are looking at £10,000–£20,000 for a complete renewable energy transformation.

With annual energy savings of £1,500–£2,500 (depending on your current fuel and electricity consumption), the payback period is typically 6–10 years. After that, you are essentially heating your home for free.