Heat Pump vs Solar Panels: Which is Best for Your Home?

If you're weighing up heat pumps vs solar panels, you're not alone. As energy prices fluctuate and sustainability becomes a growing concern across the UK, more property owners are turning to renewable energy solutions. 

Whether you're looking to lower your energy bills, reduce your carbon footprint, or increase your property's value, understanding the pros and cons of each system is essential.

This guide breaks down everything you need to know, from costs and efficiency to installation and lifespan, so you can make the best decision for your home or building.

Heat Pump vs Solar Panels: A Quick Comparison

To help you get a quick overview, here’s a side-by-side comparison of heat pumps and solar panels across the most important decision-making criteria:

How Heat Pumps Work

Heat pumps are an efficient, low-carbon alternative to traditional heating systems, but not all heat pumps are the same. 

In the UK, the two most common types are Air Source Heat Pumps and Ground Source Heat Pumps. There's also a less common option, Water Source Heat Pumps, used near lakes, rivers, or boreholes.

Each type extracts natural heat from the environment and uses it to warm your home and water, but they do it in slightly different ways.

Air Source Heat Pumps (ASHP)

How they work:

Air Source Heat Pumps absorb heat from the outside air, even when temperatures are as low as -15°C. 

The system includes an outdoor unit (which looks like an air conditioning box), and an indoor unit that distributes heat to your radiators, underfloor heating, or hot water tank.

• Think of it as a refrigerator in reverse. Instead of expelling heat, it draws it in and concentrates it to warm your home.
  
• Ideal for most UK homes, particularly well-insulated properties.
  
• Easier and cheaper to install compared to ground source systems.

Used for:

Space heating and domestic hot water.

Ground Source Heat Pumps (GSHP)

How they work:

Ground Source Heat Pumps extract heat from the ground beneath your property using a series of underground pipes (called a ground loop) filled with antifreeze solution. Even during winter, the ground maintains a relatively constant temperature, typically around 10–12°C.

• The fluid in the pipes absorbs this natural heat, which is then transferred to a heat exchanger and used to warm your home.
  
• Installation requires significant outdoor space for horizontal loops, or deep boreholes if land is limited.

Used for:

Efficient, large-scale heating for well-insulated homes and commercial buildings. Especially beneficial in new builds or properties undergoing major renovation.

Water Source Heat Pumps (WSHP)

How they work:

These systems extract heat from a nearby water source, such as a lake, river, or pond. Like ground source systems, they use a network of submerged pipes to collect and transfer thermal energy.

• Efficient but site-dependent, only suitable if you have access to a suitable water body.
  
• Rare in domestic settings but sometimes used in larger developments.

Used for:

High-efficiency heating for properties with access to consistent water sources.

How Do Solar Panels Work?

Solar panels, more specifically, solar photovoltaic (PV) panels by converting sunlight into electricity. When sunlight hits the surface of a panel, it stimulates the movement of electrons in semiconductor materials, typically silicon. 

This generates direct current (DC) electricity, which is then converted into alternating current (AC) by an inverter, making it suitable for use in your home or export to the grid.

This means solar panels can power your household appliances, lighting, and even electric heating systems using free, renewable energy from the sun. 

Any surplus energy can be stored in a or exported to the National Grid via the Smart Export Guarantee (SEG), allowing you to earn money on what you don’t use.

Modern solar PV systems can be integrated with smart meters, home energy management systems, and batteries to maximise self-consumption and savings.

Types of Solar Panels

Not all solar panels are created equal. In the UK, there are three main types of solar panels commonly installed on homes and commercial buildings:

• Monocrystalline panels
  
• Polycrystalline panels
  
• Thin-film panels

Each type has different characteristics in terms of efficiency, cost, appearance, and suitability for certain roof types and energy needs.

Selecting the right type depends on your budget, available roof space, aesthetic preferences, and energy consumption goals. While monocrystalline panels tend to be the most efficient and compact, thin-film panels offer more flexibility for unique roof structures.

Insight: Read our guide to understand the difference between monocrystalline and polycrystalline panels.

Heat Pump vs Solar Panels: What Are the Key Differences?

Which Is More Energy Efficient?

Heat pumps are considered highly energy efficient. A heat pump can achieve efficiencies of over 300%, meaning you get three or more units of heat for every unit of electricity used.

Solar panels, by contrast, typically convert 15-22% of solar energy into electricity. While this sounds low, solar PV generates free electricity over many years with no ongoing fuel input.

Insight: Read our in-depth article on solar panel efficiency to get a better understanding.

Winner: Heat Pumps for sheer efficiency ratio, though solar offers a long-term electricity solution.

Performance

Understanding how each system performs year-round is essential when deciding on the right renewable energy solution for your home. Performance can be influenced by everything from climate to insulation levels, and it directly impacts the return on investment.

Heat Pump Performance

Heat pumps are designed to extract low-temperature heat from the environment and amplify it for domestic use. Their efficiency is measured using the Coefficient of Performance (CoP). 

For example, a CoP of 3 means the system produces 3 units of heat for every 1 unit of electricity used.

• Air Source Heat Pumps (ASHP) tend to have a CoP of 2.5–3.5, depending on the outdoor temperature. Their performance can dip in very cold weather but remains effective down to around -15°C.
  
• Ground Source Heat Pumps (GSHP) offer a more consistent performance year-round due to stable underground temperatures, with a CoP of 3.5–4.5.

Key factors affecting performance:

• Level of insulation in the property
  
• Temperature of heat distribution system (e.g., underfloor vs. radiators)
  
• Outdoor temperature (for ASHP)

Solar Panel Performance

Solar panels generate electricity during daylight hours and perform best in direct sunlight. Their output depends on panel type, angle, orientation, shading, and local weather conditions. Performance is measured in kWh per kilowatt installed (kWh/kWp) annually.

• On average, a UK home solar system produces 850–1,100 kWh per kWp installed per year.
  
• Solar panels can still generate electricity even in cloudy weather, though at a reduced rate.

Key factors affecting performance:

• Roof orientation and tilt (south-facing is ideal)
  
• Shading from trees, chimneys, or neighbouring buildings
  
• Location (southern UK generally gets more solar gain)

Winner: Draw

Both technologies offer strong performance but in different ways:

• Heat pumps excel in consistent, year-round heating performance, especially ground source models.
  
• Solar panels are weather-dependent but generate free electricity with minimal maintenance, offering excellent long-term value.

Your choice should depend on your property's needs, heating vs. electricity and how well it can support each system’s optimal conditions.

Costs

Upfront costs are often the deciding factor. While heat pumps can attract government grants, installation can be costly.

Winner: Solar Panels are generally more affordable upfront.

Installation Requirements

When deciding between heat pumps and solar panels, understanding the installation process and what your property needs in advance can be the difference between a smooth upgrade and a costly headache. 

Each system comes with its own set of requirements, from physical space to structural considerations and disruption levels.

Heat Pump Installation Requirements

Air Source Heat Pumps (ASHPs):

• Outdoor Unit Space: Requires sufficient outdoor space, ideally near the kitchen or utility room. The unit needs good airflow and should be placed away from windows or neighbouring properties to avoid noise issues.
  
• Indoor Compatibility: You’ll need space for an indoor unit, which connects to your existing heating system and possibly a hot water cylinder.
  
• System Compatibility: Works best with underfloor heating or low-temperature radiators. Older systems with single-panel radiators may require upgrades.
  
• Home Insulation: Highly dependent on the thermal efficiency of your home. Upgrades to cavity wall insulation, loft insulation, or double glazing may be necessary.
  
• Disruption Level: Installation typically takes 2–5 days and may require access to your heating and hot water systems.

Ground Source Heat Pumps (GSHPs):

• Outdoor Land Area: Requires significant land for horizontal ground loops, or borehole drilling equipment for vertical loops, suitable for rural homes, large gardens, or new developments.
  
• Trenching or Drilling: Installation involves excavating trenches or boreholes, which can be disruptive and expensive.
  
• Indoor Space: As with ASHPs, you'll need room for a heat pump unit and a hot water cylinder.
  
• Disruption Level: Significantly more disruptive and complex than ASHPs. Installation can take 1–3 weeks, especially if groundwork is extensive.

Solar Panel Installation Requirements

• Roof Orientation: Ideally, a south-facing roof with minimal shading offers the best performance. East- and west-facing roofs can still be viable, though slightly less efficient.
  
• Roof Size & Structure: A typical 4kW system requires around 25–30m² of roof space. The roof must be structurally sound to support the weight of solar panels.
  
• Planning Permission: Usually not required for residential properties under permitted development rights, but listed buildings or properties in conservation areas may need approval.
  
• Inverter & Optional Battery: Requires indoor space for an inverter (usually installed in a loft or garage), and possibly a battery.
  
• Disruption Level: Minimal. Installation is usually completed within 1–2 days, with very little impact on your home.

Winner: Solar Panels

Solar panels require less disruption, fewer structural changes, and a simpler installation process overall. 

While heat pumps may need significant space, system upgrades, and insulation improvements, solar panels can be retrofitted to most properties with relative ease, making them the more accessible choice for the majority of UK homeowners.

What Are the Maintenance and Servicing Requirements?

Heat pumps need annual servicing to ensure efficiency and longevity. Solar panels require minimal upkeep, just occasional cleaning and inverter checks.

Winner: Solar Panels for lower cost and simplicity.

What Is the Typical Lifespan?

Most heat pumps last between 15 and 20 years. Solar panels can last over 30 years with proper care.

Winner: Solar Panels due to their long operational life.

Which Is More Suitable for Different Property Types?

Choosing between a heat pump and solar panels depends heavily on the type, age, and condition of your property, particularly insulation levels, available space, and roof characteristics.

Heat Pumps

Heat pumps, especially Air Source Heat Pumps (ASHPs) and Ground Source Heat Pumps (GSHPs), work best in properties that are already energy-efficient or can be upgraded to high insulation standards.

Air Source Heat Pumps are ideal for:

• Modern, well-insulated homes
  
• Retrofitted properties with upgraded insulation
  
• Homes with underfloor heating or oversized radiators that operate effectively at lower temperatures
  
• Properties with some outdoor space to accommodate the external unit
  
• Flats and semi-detached homes with space-efficient ASHP models (subject to noise and placement considerations)

Ground Source Heat Pumps are best suited to:

• Large detached homes, farmhouses, or rural properties with ample outdoor space for ground loops or room for boreholes
  
• New build properties, where the system can be integrated into the construction process
  
• Commercial buildings or schools undergoing renovation with long-term heating needs
  
• Projects where disruption during installation is acceptable or planned for

Note: Homes with poor insulation, old windows, or single radiators may require significant efficiency upgrades before a heat pump is viable and even then, performance may be compromised without improvements.

Solar Panels

Solar PV panels are far more universally applicable and can be installed on a wide range of property types:

• Detached, semi-detached, and terraced homes with decent roof space
  
• Flats with access to unshaded roof areas (subject to planning and freeholder approval)
  
• Bungalows, farmhouses, and cottages
  
• Commercial properties and buildings with large, unshaded roof areas
  
• Outbuildings, garages, or carports (if structurally suitable)

Key requirements for optimal performance include:

• A south-facing or south-west facing roof
  
• Minimal shading from nearby trees, buildings, or chimneys
  
• A roof pitch of around 30–40° is ideal but not essential

Even east- or west-facing roofs can benefit from solar, though with slightly reduced output.

Winner: Solar Panels

Solar panels are more broadly suitable across a wide range of properties, from compact terraced houses to large commercial buildings. 

Their flexibility, minimal disruption, and fewer prerequisites (like insulation or radiator upgrades) make them a better fit for most UK homeowners and landlords. 

Heat pumps, while highly efficient, are more dependent on specific property conditions and layout.

Grants Available

Government grants and incentive schemes can significantly reduce the upfront cost of renewable energy systems. 

Whether you're a homeowner looking to cut your heating bills or a landlord aiming to improve EPC ratings, it's important to understand what support is available.

Heat Pump Grants

Boiler Upgrade Scheme (BUS):

• The Boiler Upgrade Scheme offers up to £7,500 towards the cost of installing air source or ground source heat pumps in England and Wales.
  
• Available for owner-occupied homes and small landlords.
  
• The property must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation.
  
• Ground source heat pumps often require higher upfront costs, but the grant applies equally to both air and ground systems.

Home Energy Scotland Grant and Loan (Scotland only):

• Grants of up to £7,500 plus optional interest-free loans available for heat pump installations.
  
• Additional funding may be available if you're in a rural or remote area.

Solar Panel Grants

ECO4 Scheme (Energy Company Obligation):

• With the ECO4 scheme, some eligible low-income households may qualify for free or heavily subsidised solar panels as part of wider energy efficiency upgrades.
  
• This depends on income, benefits status, and whether the home has poor energy performance.

Financial Incentives

Smart Export Guarantee (SEG):

• The Smart Export Guarantee allows households with solar PV systems to earn money for exporting unused electricity back to the grid.
  
• Payments are made by energy suppliers, and rates vary depending on your provider.

Winner: Heat Pumps

Heat pumps currently benefit from more substantial upfront financial support. The Boiler Upgrade Scheme in particular makes them far more accessible, especially given their higher installation costs. 

While solar panels offer long-term savings through SEG, they lack equivalent upfront grant support.

Heat Pump vs Solar Panels: Which One Should You Choose?

If you’re trying to choose between a heat pump and solar panels, consider the following factors:

• Your energy goals: Want to cut heating costs? A heat pump may be better. Want to lower electricity bills? Solar is ideal.
  
• Property type: Solar works on most buildings. Heat pumps need insulation and space for installation.
  
• Budget: Solar panels usually cost less upfront.
  
• Environmental goals: Both technologies significantly reduce your carbon footprint.

For many UK homeowners, the ideal solution may be both. Solar panels can generate the electricity needed to power a heat pump, creating a low-carbon, closed-loop system.

Using Solar Power to Run Your Air Source Heat Pump 

Pairing allows you to generate your own renewable electricity to power your heating system. 

Since heat pumps run on electricity, using solar-generated power reduces your reliance on the grid, especially during daylight hours.

How It Works Together:

• During the day, your solar panels generate electricity.
  
• That electricity can be used to power your heat pump (along with other household appliances).
  
• Any excess electricity can be stored in a battery for evening use or exported back to the grid under the Smart Export Guarantee (SEG).

Ideal For:

• Well-insulated homes aiming to lower both heating and electricity bills.
  
• Households looking to maximise renewable energy use and reduce carbon footprint.
  
• Properties with suitable roof space and orientation for solar installation.

Benefits of Combining Both:

• Lower energy bills by powering your heat pump with free solar energy.
  
• Reduced carbon emissions from cleaner energy use.
  
• Enhanced return on investment over time.

Considerations:

• Upfront costs are higher when installing both systems.
  
• Battery storage may be needed for maximum efficiency.
  
• Proper system sizing and compatibility should be assessed by a qualified installer.

FAQs

1. Can I install both heat pumps and solar panels on the same property?

Yes. In fact, combining both systems can maximise efficiency and reduce your reliance on the grid even further.

2. Are there grants available in the UK for solar panels or heat pumps?

Yes. The UK Government offers the Boiler Upgrade Scheme for heat pumps and the Smart Export Guarantee for solar panels.

4. Will solar panels still work on cloudy days?

Yes. While they produce less energy than on sunny days, solar panels still generate power from daylight, not just direct sunshine.

5. Can I store solar energy to use at night?

Yes. Pairing your solar panel system with a battery storage solution lets you use the energy you generate, even after the sun goes down.

Our Verdict

Both heat pumps and solar panels offer unique benefits for UK homeowners and landlords looking to reduce energy bills and carbon emissions. Heat pumps excel at heating efficiently, while solar panels help generate clean, renewable electricity.

Choosing the best option depends on your home, your budget, and your energy priorities. 

Whichever you choose, investing in renewable energy is a smart, future-proof move and with support from schemes like the Boiler Upgrade Scheme and Smart Export Guarantee, it’s more accessible than ever.

If you're thinking about solar, don’t forget to get your free quotes from Eco Answers and see how much you could save.