Can Solar Panels Power an Air Source Heat Pump?

As energy costs rise and the UK pushes towards net-zero emissions by 2050, many homeowners, landlords, and commercial property owners are exploring sustainable energy solutions. 

A common question is: can solar panels power an air source heat pump? The answer is yes, and combining these technologies can significantly reduce energy bills and carbon footprints. 

This blog post dives into how solar panels and air source heat pumps work together, their costs, savings, and practical considerations for UK properties. 

Whether you’re a homeowner looking to cut costs or a landlord aiming to boost property value, we’ll help you make an informed decision.

Can Solar Panels Run an Air Source Heat Pump?

Yes, solar panels can power an air source heat pump (ASHP), creating a highly efficient, eco-friendly system for heating and powering your home or commercial property. 

Solar panels generate electricity from sunlight, which can be used to run an ASHP, a low-carbon heating system that extracts heat from the outside air. 

According to the Energy Saving Trust, pairing solar panels with an ASHP can lower both electricity and heating bills, potentially saving households up to £1,300 annually depending on usage and system size.

The synergy between these technologies lies in their ability to reduce reliance on grid electricity and fossil fuels. 

For example, a typical 3-bedroom UK home uses around 2,700 kWh of electricity and 11,500 kWh of gas annually for heating, as per Ofgem. 

An ASHP, with an efficiency of around 300%, requires approximately 3,833 kWh of electricity to replace gas heating, totaling 6,533 kWh when combined with other household needs. 

A well-sized solar panel system, especially with battery storage, can cover a significant portion of this demand, making your property more energy-independent.

What Are the Benefits of Combining Solar Panels with Air Source Heat Pumps?

The benefits of combining solar panels with air source heat pumps include:

• Reduced Energy Bills: Solar panels produce free electricity during daylight hours, which can power your ASHP, slashing heating costs. Special tariffs, like heat pump-specific plans, can further reduce expenses.Read our article on how solar panels can reduce your electricity bill for more insights.
  
  
• Lower Carbon Footprint: Using solar energy to run an ASHP can reduce household carbon emissions by up to 2.6 tonnes of CO2 per year.
  
  
• Increased Property Value: Homes with energy-efficient systems like ASHPs and solar panels can increase in value by up to 6.8%. Take a look at our article on how solar panels can increase your property value for more insights.
  
  
• Government Incentives: Schemes like the Boiler Upgrade Scheme offer £7,500 grants to offset ASHP installation costs, while the Smart Export Guarantee (SEG) pays for surplus solar energy exported to the grid.
  
  There are also dedicated solar panel grants for businesses.

To find out how much you could save, use Eco Answers’ Quote-Comparison Tool to connect with trusted installers for bespoke solar and ASHP solutions.

How Many Solar Panels Are Needed to Power an Air Source Heat Pump?

The number of solar panels required depends on your property’s energy needs, the ASHP’s efficiency, and your location in the UK. 

On average, a 3.5kW solar PV system (around 10 panels) produces approximately 2,650 kWh annually, which is close to the 3,833 kWh needed for an ASHP in a typical 3-bedroom home. 

However, when factoring in other household appliances (around 2,700 kWh annually), a larger 5-7kW solar system (12-20 panels) is often recommended to fully power both the ASHP and household needs.

Here’s a breakdown of solar panel requirements:

When sizing a solar panel system for your home, it’s important to consider the energy consumption of individual appliances. 

For example, understanding what you can power with a 100-watt solar panel helps set expectations for smaller devices and electronics. 

What Factors Affect Solar Panel Requirements

• Property Size and Energy Efficiency: Well-insulated homes require less heating, reducing ASHP electricity needs. Check your Energy Performance Certificate (EPC) rating to assess efficiency.
  
  
• ASHP Efficiency: Most ASHPs have a Coefficient of Performance (COP) of 3, meaning they produce 3 units of heat for every unit of electricity. Higher COPs reduce electricity demand.
  
  
• Location and Sunlight: Southern UK regions like London receive more sunlight, generating up to 3,400 kWh annually from a 4kW system, compared to northern areas. This makes it crucial to understand solar panel efficiency and why solar panels require direct sunlight to perform effectively.
  
  
• Battery Storage: Without a battery, solar energy can’t be used at night, requiring grid electricity for evening ASHP use. A battery stores excess daytime energy for 24/7 use. Read our guide to learn more about the cost of solar battery systems before deciding.

For a customised system size, use Eco Answers’ Quote-Comparison Tool to get quotes from accredited installers.

What Are the Costs and Savings of Combining Solar Panels and ASHPs?

The upfront cost of installing solar panels and an ASHP can be significant, but government grants and long-term savings make it a worthwhile investment. 

According to the Energy Saving Trust, a combined system for an average UK home costs around £20,000 before grants, with ASHPs costing £11,000 and a 4kW solar system costing £5,000-£6,000. 

The Boiler Upgrade Scheme reduces ASHP costs by £7,500, bringing the total to approximately £12,500.

Cost Breakdown

Potential Savings

• Energy Bill Reductions: A solar-powered ASHP can save up to £1,300 annually, with solar panels contributing £500-£750 and ASHPs reducing gas bills.
  
  
• Smart Export Guarantee (SEG): Earn 15p/kWh for surplus solar energy exported to the grid, potentially netting £200-£300 annually for a 4kW system.
  
  
• Payback Period: With grants and savings, the system can pay for itself in 10-12 years, with panels lasting 25+ years.

Is Your Property Suitable for Solar Panels and an ASHP?

Most UK properties are suitable for solar panels and ASHPs, but specific requirements must be met to maximise efficiency and savings.

Property Requirements

• Roof Space: Solar panels need a south-facing, unshaded roof for optimal performance. East or west-facing roofs work but produce 10-20% less energy. If roof space is limited, installing solar panels in your garden might be a viable alternative.
  
  Additionally, it’s worth knowing how many solar panels you can fit on your roof.
  
  
• Outdoor Space: ASHPs require a small outdoor unit (similar to an air conditioner) and indoor space for a water tank and inverter.
  
  
• Energy Efficiency: Properties with EPC ratings of D-G may qualify for free installations under the ECO4 scheme if low-income or vulnerable households are involved.
  
  
• Planning Permission: Most installations don’t require permission unless the property is listed or in a conservation area. Read our guide on planning permission for solar panels before starting your project.

Landlords can benefit from increased rental appeal and property value, while commercial properties can reduce operational costs. Check eligibility for grants like ECO4 or the Warm Homes Plan to offset costs.

How Can You Maximise Efficiency of Solar Panels and ASHPs?

To get the most out of your system, consider these strategies:

• Install a Solar Battery: Store excess solar energy for evening use, ensuring your ASHP runs on clean energy 24/7.
  
  
• Use Smart Tariffs: Special heat pump tariffs, like those from Octopus Energy, reduce running costs by up to 20%.
  
  
• Optimise Radiators: ASHPs work best with larger radiators to distribute heat efficiently.
  
  
• Regular Maintenance: Clean solar panels and service ASHPs annually to maintain performance.
  
  
• DIY vs Professional Installation: While tempting, installing solar panels yourself may not meet compliance and warranty standards.

FAQs 

How do seasonal changes affect solar panel and ASHP performance?

Solar panels produce less electricity in winter due to shorter daylight hours, but a 4kW system can still meet most of a home’s needs with battery storage. 

ASHPs are less efficient in colder temperatures but remain effective down to -15°C. If you're wondering whether solar panels work on cloudy days, the answer is yes, they still generate electricity, just at reduced output. Read our guide to learn how much electricity solar panels generate per day.

Can I use solar panels to power an ASHP in a rented property?

Yes, but you’ll need landlord permission. The ECO4 scheme may cover costs for low-income tenants, and installations can increase rental appeal.

What maintenance is required for a combined system?

Solar panels need occasional cleaning and annual inspections, while ASHPs require yearly servicing to check refrigerant levels and components, costing £100-£200 annually. Read our guide on solar panel maintenance for more insights.

Routine upkeep helps prevent performance issues, but if your system ever seems underperforming, it’s worth understanding some of the most common reasons solar panels stop working to diagnose potential faults.

Are there additional grants for commercial properties?

Commercial properties may qualify for the Warm Homes: Local Grant or green finance options through banks, depending on local authority schemes.

How do solar diverters enhance ASHP systems?

A solar diverter redirects excess solar energy to heat water, reducing ASHP workload and saving an additional £100-£200 annually, per the Energy Saving Trust.

Final Thoughts

Combining solar panels with an air source heat pump offers UK homeowners, landlords, and commercial property owners a powerful way to cut energy costs, reduce carbon emissions, and enhance property value. 

With government grants like the Boiler Upgrade Scheme and SEG payments, the initial investment becomes more affordable, and savings of up to £1,300 annually make it a smart long-term choice. 

By assessing your property’s suitability and optimising with batteries or smart tariffs, you can maximise efficiency and sustainability. It’s one of the key benefits of solar panels.

If you're still deciding between options, learn more in our comparison of heat pumps vs solar panels for standalone systems.

Start your journey to a greener future with Eco Answers’ Quote-Comparison Tool to find the best solar and ASHP solutions for your needs.