Solar Panels and Heat Pumps: Why They Work So Well Together

Why Solar Panels and Heat Pumps Work Together

A heat pump uses electricity to generate heat. Solar panels generate free electricity from sunlight. When you pair the two, your solar panels can power your heat pump during the day, dramatically reducing running costs.

During spring, summer, and autumn, a typical domestic solar array generates more than enough electricity to run a heat pump for hot water and any background heating. Even in winter, solar panels contribute meaningful electricity on clear days, offsetting some of the heat pump's consumption during the coldest months when it works hardest.

How Much Can You Save?

Based on installations we have completed across Cornwall:

• Heat pump alone: £500–£900/year running cost
• Heat pump + solar panels: £300–£600/year running cost
• Heat pump + solar + battery: £200–£450/year running cost

That is a potential saving of up to 60% on heating costs compared to a heat pump running on grid electricity alone. Compared to a gas boiler at £800–£1,200/year, the combined system can cut your heating costs by 60–80%.

For full pricing details, see our solar panel cost guide and heat pump cost guide.

System Sizing: Getting the Balance Right

The ideal system size depends on your property, roof orientation, and heating demand. As a general guide for a 3-bedroom home in Cornwall:

• Heat pump: 8–12 kW capacity (sized to your home's heat loss calculation)
• Solar panels: 3.5–5 kW system (10–14 panels), generating 3,500–5,000 kWh per year
• Battery (optional): 5–10 kWh capacity to store daytime solar for evening use

We design every system specifically for the property. During your free home survey, we assess roof space, orientation, shading, insulation levels, and heating requirements to size everything correctly.

Adding Battery Storage

A battery storage system significantly improves the economics of a solar-and-heat-pump combination. Without a battery, you export excess solar electricity during the day (earning 5–15p/kWh via the Smart Export Guarantee) and buy it back from the grid in the evening at 24p+/kWh.

With a battery, you store that excess solar electricity and use it in the evening when the heat pump runs for hot water and heating. This can increase your self-consumption of solar electricity from around 40% to over 80%.

Installation Costs and Available Funding

The combined cost of a heat pump and solar panel system varies by property but typical ranges are:

• Heat pump: £8,000–£14,000 (before £7,500 BUS grant)
• Solar panels: £5,000–£9,000 (0% VAT applies)
• Battery storage: £3,000–£6,000 (0% VAT when installed with solar)

After the BUS grant and VAT savings, a combined system can cost from around £8,500 — and will save you money every year for decades. See our full grants and funding guide for all available schemes.

Is It Worth Combining Both?

In most cases, yes. The combination offers the lowest running costs of any heating system, future-proofs your home against energy price rises, and adds significant property value. Many of our customers in St Austell, Newquay, Bodmin, and across Cornwall are installing both together.

If budget is a concern, we can phase the installation — heat pump first (with the grant), then solar panels later. The systems work independently and can be combined at any time.

Book a free home survey to get a tailored assessment and quote for your property.