Heat Pump and Solar PV: The Whole-Home Energy System

Q: How much does a combined heat pump and solar PV system cost?

A typical air source heat pump costs about £11,128 to £15,627 installed before the grant (DESNZ, middle half of installs), and a 4kW solar system about £5,000-7,000, so roughly £16,100-22,600 together. After the £7,500 BUS grant for the heat pump, the net cost is roughly £8,600-15,100. Payback depends on your usage, tariff and how much solar you use yourself.

Q: What are the annual savings from solar + heat pump?

On our example (12,000 kWh of heat a year), a heat pump on a Cosy-style time-of-use tariff costs about £685 a year in electricity, against about £1,063 for a gas boiler at price cap rates: a saving of about £378 before solar. Solar panels reduce the electricity you buy further, by an amount that depends on your system and how much of its output you use.

Q: Should I install both at the same time?

It is not essential but can be more convenient. Installing both together may save on scaffolding and electrical work. However, getting the heat pump first (with the £7,500 BUS grant, or £9,000 if you are replacing oil or LPG off the gas grid until 31 March 2027) and adding solar later works fine too.

Q: Do I need a battery for the combined system?

Not essential. Your hot water cylinder acts as free thermal storage. A battery adds £5,000-10,000 with marginal additional savings. Consider adding one in 2-3 years when battery prices fall further.

By Home Heat Pump Guide Published 18 March 2026

UK home with solar panels on the roof and air source heat pump in the garden forming a complete renewable energy system — Solar PV and a heat pump together create the UK's most cost-effective and lowest-carbon home energy system.

A heat pump plus solar PV can cut your annual heating costs well below a gas boiler's. On our example home, a heat pump on a Cosy-style time-of-use tariff costs about £378 a year less to run than a gas boiler at October 2026 price cap rates, before any solar. This whole-home energy system combines daytime solar electricity with cheaper time-of-use tariff rates.

This guide covers the economics of combining both technologies, the grants available, sizing advice, and how to maximise the benefit from your integrated heat pump and solar panel system.

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The Combined Economics

Scenario	Annual Heating + Hot Water Cost	Annual Saving vs Gas Boiler
Gas boiler (standard tariff)	£1,063	—
Heat pump (standard tariff)	£987	£76
Heat pump + Cosy-style tariff	£685	£378
Heat pump + Cosy-style tariff + 4kW solar	Lower still, depending on solar use	More than £378

Unit rates only, Ofgem price cap 1 October 2026 to 31 December 2026: gas boiler 12,000 kWh heat at 90% efficiency and 7.97p/kWh; heat pump COP 3.2 (3,750 kWh) at 26.32p/kWh; Cosy-style = 60% of use in cheap windows 51% below a day rate taken as the price cap rate. Standing charges excluded. Solar savings depend on your system and are not estimated here.

UK homeowner comparing dramatic energy bill savings from combined heat pump and solar panel system — The combined system delivers the biggest savings compared with gas.

Grants and Funding

Heat Pump Grant

BUS: £7,500 (£9,000 replacing oil or LPG off the gas grid, to 31 March 2027)

Solar VAT

0% VAT on residential solar until 31 March 2027

Net System Cost

About £8,600-15,100 after grant

Combined Payback

Depends on usage and tariff

System Sizing

Heat pump: Size based on your home's heat loss calculation — typically 5-12 kW for most UK homes. Your MCS installer will specify this
Solar PV: A 4kW system (10-12 panels) is ideal for most 3-4 bed homes with a heat pump. See the Home Solar Guide for detailed sizing
Hot water cylinder: 200-300L recommended — acts as thermal storage for surplus solar

Maximising the Combination

Use a solar diverter: Automatically diverts surplus solar to your hot water cylinder via the heat pump
Schedule daytime hot water: Run the heat pump for hot water during peak solar hours
Use Octopus Cosy for overnight: Solar covers daytime; Cosy's cheap windows (51% below the regional day rate) cover overnight and afternoon heating
Monitor with smart meter: Track self-consumption and identify optimisation opportunities
Consider export tariffs: Earn income from surplus solar you cannot use

Hot water cylinder storing free solar energy from heat pump operation during daytime hours — Your hot water cylinder stores surplus solar energy as heat — free hot water from free sunshine.

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UK detached house with combined solar panels and heat pump installation showing whole-home renewable energy system — The whole-home energy system: solar on the roof, heat pump in the garden, smart tariff for the grid.

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Frequently Asked Questions

How much does a combined heat pump and solar PV system cost?

A typical air source heat pump (£11,128-£15,627 before grant, DESNZ) plus 4kW solar (£5,000-7,000) totals roughly £16,100-22,600. After the BUS grant (£7,500), net cost is roughly £8,600-15,100; payback depends on your usage, tariff and solar self-consumption.

What are the annual savings from solar + heat pump?

Combined savings of £680-930 per year compared to a gas boiler. See our full cost-reduction guide.

Should I install both at the same time?

Not essential. Getting the heat pump first (with the £7,500 grant, or £9,000 if replacing oil or LPG off the gas grid until 31 March 2027) and adding solar later works fine.

Do I need a battery for the combined system?

Not essential currently. A battery adds £5,000-10,000 with marginal additional savings. Your hot water cylinder provides free thermal storage.

The Whole-Home Energy Future

The combination of heat pump, solar PV, and smart tariffs represents the future of UK home energy. The Boiler Upgrade Scheme and zero-VAT solar make this combination increasingly affordable. With proper insulation, the right electricity tariff, and smart controls, UK homes can achieve near-zero-carbon heating at costs below gas — fulfilling the promise of the heat pump transition.