How to Combine Solar Panels with an Air Source Heat Pump in London

As London continues its push toward net-zero carbon targets, homeowners are increasingly looking for ways to upgrade their heating systems and reduce energy bills. Among the most promising eco-friendly solutions is the combination of solar panels with an air source heat pump (ASHP). When integrated effectively, these two technologies can work together to dramatically cut your carbon footprint and energy costs.

In this blog, we’ll guide you through how to combine solar panels with an air source heat pump in London, the benefits of doing so, and what to consider before installation.

Understanding the Basics

What Are Air Source Heat Pumps?

An air source heat pump absorbs heat from the outside air—even in cold temperatures—and uses it to heat your home and water. It works much like a refrigerator in reverse, transferring heat using electricity.

There are two main types:

• Air-to-water heat pumps: These heat water that circulates through radiators or underfloor heating.

• Air-to-air heat pumps: These circulate warm air using fans and are not used for hot water.

What Are Solar Panels?

Solar panels, or photovoltaic (PV) panels, convert sunlight into electricity. This electricity Loft Insulation London can be used to power your home or stored in a battery for later use. In London, despite the cloudier climate, solar PV panels still perform well thanks to advancements in solar technology.

Why Combine Solar Panels with an Air Source Heat Pump?

Combining solar panels with an air source heat pump offers significant synergy:

1. Lower Energy Bills: The heat pump runs on electricity, which can be partially or entirely powered by your solar panels.

2. Reduced Carbon Emissions: You're cutting down on fossil fuels by using renewable energy sources.

3. Increased Energy Independence: Less reliance on the grid and protection from rising energy prices.

4. Maximised Use of Solar Energy: Instead of sending excess electricity back to the grid, it powers your heating system.

5. Government Incentives: London residents may be eligible for various grants and subsidies for installing renewable systems.

Step-by-Step Guide to Combining Solar Panels with an Air Source Heat Pump

1. Evaluate Your Home’s Suitability

Start by assessing whether your home can accommodate both systems:

• Roof Space and Orientation: South-facing roofs are ideal for solar panels. East- and west-facing are also viable.

• Outdoor Space: Air source heat pumps require space for the unit, ideally with good airflow.

• Insulation: Both technologies are most effective in well-insulated homes. Check wall, roof, and floor insulation before investing.

2. Energy Demand Calculation

Before installation, it's crucial to understand your household’s energy consumption:

• Heating and Hot Water Needs: How much heat do you require daily, especially in colder months?

• Electricity Use: Will your solar PV system cover enough of your usage to make the heat pump efficient?

Energy consultants or installers can perform a detailed site survey and recommend the correct system size.

3. Choose the Right Size Systems

Both systems must be properly sized:

• Air Source Heat Pump Sizing: Undersized pumps will not provide adequate heating; oversized ones will cycle inefficiently.

• Solar PV System Sizing: Aim for a system that can produce electricity during daylight to offset the pump’s usage.

For example, a 4kW solar PV system paired with a standard air-to-water heat pump might be suitable for a 3-bedroom home in London.

4. Installation Considerations

Professional Installers

Choose certified installers, preferably MCS (Microgeneration Certification Scheme) accredited, to ensure quality and access to financial incentives.

Installation Process

• Solar Panels: Usually installed on your roof, connected to an inverter and optional battery.

• Air Source Heat Pump: Typically placed on an external wall or garden space. Connected to your home’s central heating or hot water system.

Installation generally takes a few days for each system.

Battery Storage

Adding a solar battery allows you to store excess solar energy  Room in Roof Insulation London generated during the day and use it when needed—especially to run the heat pump during early morning or evening hours when solar output is low.

5. Integrate with a Smart System

To optimise efficiency:

• Smart Controls: These manage energy use based on solar production, weather forecasts, and heating needs.

• Timers and Thermostats: Schedule the heat pump to run when solar generation is at its peak.

A well-integrated system ensures you're using your solar power effectively and not drawing unnecessarily from the grid.

6. Consider London-Specific Factors

Weather Conditions

Although London doesn’t get as much sunlight as southern Europe, modern solar panels are efficient even on cloudy days. Similarly, air source heat pumps function well in mild climates like London’s, where temperatures rarely drop below -5°C.

Planning Permission

Most residential installations are allowed under permitted development rights. However, check with your local council for any restrictions, especially if you live in a conservation area or listed building.

7. Maintenance and Monitoring

Both systems are low-maintenance:

• Solar Panels: Require occasional cleaning and inverter checks.

• Heat Pump: Annual servicing is recommended to maintain efficiency.

Use monitoring apps to track performance, energy savings, and any issues.

8. Financial Considerations and Incentives

Installation Costs (as of 2025)

• Air Source Heat Pump: £8,000–£14,000 (depending on size and complexity)

• Solar PV System (4kW): £5,000–£7,000

• Battery Storage (optional): £3,000–£5,000

Incentives and Support

• Boiler Upgrade Scheme (BUS): Offers grants of up to £7,500 for replacing a gas boiler with a heat pump.

• Smart Export Guarantee (SEG): You can earn money by exporting unused solar electricity to the grid.

• Zero VAT: There is currently 0% VAT on energy-saving materials, including solar panels and heat pumps.

These schemes make the combination of solar and heat pumps more affordable and accessible to London homeowners.

9. Environmental Benefits

Combining these technologies can dramatically cut your home’s carbon footprint:

• Traditional Gas Boiler: Emits around 2.5 tonnes of CO₂ per year.

• ASHP + Solar: Can reduce emissions to below 0.5 tonnes/year.

In London, where the push for green homes is strong, this transformation not only helps the environment but can also boost your property value.

10. Future-Proofing Your Home

The UK government plans to phase out gas boilers by 2035. Installing renewable systems like solar panels and air source heat pumps now positions your home ahead of future regulations and energy trends.

You’ll also be more resilient to rising fuel prices and power outages when your home is powered by your own clean energy.

Conclusion

Combining solar panels with an  Air Source Heat Pump in london in London is a smart, sustainable choice for forward-thinking homeowners. While the initial investment may seem significant, the long-term savings, reduced carbon footprint, and potential financial incentives make it worthwhile.

With careful planning, a good understanding of your energy needs, and professional installation, you can turn your home into an energy-efficient powerhouse—ready for a greener London future.