vaillant 10kw air source heat pump, cost of heat pump, heat pump price

How Do Air Source Heat Pumps Work?

Air source heat pumps are a modern solution for heating your home and providing hot water. They harness the power of the outside air, even when temperatures drop significantly, to generate heat energy. This energy is then used to warm your radiators, underfloor heating system, or hot water tank. There are two main types of heat pumps used in homes: air-to-water and air-to-air heat pumps, with air-to-water being particularly suited to British homes built with a wet heating system, providing an efficient way to transfer heat through your home.

Air source heat pump systems are not only renewable but can also be cost-effective, saving you money in the long term through energy bill savings. They require less energy than traditional heating systems and are powered by electricity which is a greener option for reducing your carbon footprint, providing that your electricity is produced by renewable sources. Furthermore, certain government incentives such as the Boiler Upgrade Scheme can help with the initial costs, and help homeowners in England to make the shift.

Heat Pump Overview

Heat pumps are emerging as the number one choice for domestic heating for homes and buildings throughout the UK, the advances in technology and a deeper understanding of how to maximise the output of heat pumps mean that heat pumps are here to stay.  

Gas Boiler Ban In 2025

The UK government has finally confirmed plans to ban gas and “hydrogen-ready” boilers in new homes built in England starting in April 2025. This decision comes after a long-awaited consultation on low-carbon building standards.

The proposals suggest that heat pumps will likely become the standard heating system for new homes. This aligns with the government’s goal of making all new houses “net zero ready” by 2025, meaning they’ll produce very low levels of carbon emissions.

The consultation process also ruled out alternative options like hybrid heat pumps and “hydrogen-ready” boilers for new builds. This decision was based on the conclusion that using any fossil fuel heating system, even those designed for future hydrogen use, wouldn’t achieve significant carbon reductions, hindering progress towards net zero.

Expenses of Heat Pump Installations

It is no secret that the cost of installing an air source heat pump is a significantly larger expense than a combi boiler. Yet, over a few years, the higher upfront cost gradually balances out due to the lower consumption of energy and in turn, reduced energy bills. To sweeten the deal, a £7,500 subsidy from the Boiler Upgrade Scheme brings the opportunity to install a heat pump to a much wider audience than before, by bringing costs in line, or sometimes to be even cheaper than the cost of traditional heating systems. 

Types Of Heat Pumps

There are two types of heat pumps that make up over 99% of all heat pumps sold:

    • Air-to-Air: Warms or cools your home by funnelling outdoor air through a duct system.
    • Air-to-Water: Transfers heat into a water heating network for your radiators or underfloor system.

For the purpose of this guide, we will be mainly focusing on air-to-water heat pumps. In the UK most houses are built with a wet heating system which is connected to radiators or underfloor heating. Due to the UK being a colder country in general, wet systems are favoured to keep homes warm in the winter. Air-to-air systems require ventilation ducts to be installed in homes which isn’t a standard practice for our English homes, this is why air-to-air systems are more common in warmer countries that require cooling.

Will Heat Pump Prices Come Down?

While heat pump installation costs are based on factors like pump capacity and installation complexity, you can anticipate substantial savings on your annual heating expenses, sometimes saving up to two-thirds. The systems are impressively efficient, with operating efficiencies of over 400%, compared to traditional boilers at 90%.

If you are banking on costs reducing before you install a heat pump, then you are likely to be waiting forever. I have been working in the industry for over 10 years, and the costs have only gone in one direction, which isn’t likely to change any time soon.

There are a few reasons why costs are going up, by looking at the total cost of an installation, it is hard to see where the cost reductions are going to come from. The components of a heat pump are predominantly manufactured in Asia, which results in large shipping expenses to get the equipment around the world to us. Other essential materials required like copper piping, or water cylinders do have consistent pricing which has seen above inflation increases over the last 20 years. To install the system, plumbers and electricians will be required, with work spread over several days, there is already a shortage of tradesmen which is pushing labour prices to highs never seen before. There are also other essential charges for businesses, such as office staff and memberships to schemes such as the MCS, and HEIS.

There is the possibility for funding levels to change however, which could go up or down for the consumer. The British government have a track record of unpredictability, however in my opinion I think it is highly unlikely that further funding will be made available due to the current economic climate. The Boiler Upgrade Scheme is confirmed to run until at least March 2025, which means the government’s £7,500 voucher will significantly reduce the net cost of installing a heat pump until then.

One factor which can help you control costs the most is how well your home is insulated. A well-insulated home ensures minimal heat loss, enhancing the pump’s performance and leading to better savings, a well insulated home will also mean you require a smaller heat pump capacity, smaller radiators and this results in lower upfront installation costs.

Remember that energy efficiency not only reflects on your energy bills but also contributes to a more sustainable living environment. Hence, while the initial price might appear steep, the long-term benefits of a heat pump system are both financially and environmentally significant.

Heat Pump How It Works – Explained

A heat pump operates by moving heat from one location to another using a refrigerant. This system uses the thermal energy present in outdoor air or ground to heat your home. It’s a bit like your fridge, but instead of keeping things cool, it warms your living spaces.

Principles at Work:

  • Thermal Transfer: Heat naturally travels from warmer to cooler areas. Heat pumps exploit this by collecting heat from the environment and transferring it indoors.
  • Cycles of Operation: Inside the pump, a refrigerant captures external heat as it evaporates into a gas, then a compressor raises the temperature of this gas.
  • Efficiency: Despite requiring electricity to operate, heat pumps are energy efficient. They do not burn fossil fuels, making them a cleaner choice for heating.

Due to their design, they have the ability to function in a spectrum of temperatures, you can rely on heat pumps to provide warmth even in the depths of a cold British winter! Some models will still work well at temperatures as low as -25°C, which is far below the lowest temperatures that are seen in the UK.

Types of Air to Water Heat Pumps:

  • Air Source: These extract heat from the air. An external unit with coils and a fan draws in outdoor air, heats the refrigerant, then sends it indoors into a wet heating system.
  • Ground/Water Source: These gather heat from the ground or water. They work similarly but start with warmth from underground or water sources to provide heating.

When you have a heat pump installed, a loop system consisting of an evaporator coil, compressor, and condenser coil works continuously. This means the process of absorbing and releasing heat is sustained, ensuring your home stays warm consistently.

Understanding the Mechanics:

The external part of an air-source heat pump features coils filled with refrigerant. The outside air is pulled over these coils by a fan, heating the refrigerant, which evaporates and is compressed to further increase the temperature. The refrigerant then travels indoors to release the captured heat before cycling back outside to restart the process.

Adopting heat pump technology has become increasingly popular for their efficiency and sustainability, making them a favoured choice in future proof home designs.

Fundamental Operations of a Heat Pump

Heat naturally moves from an area of higher temperature to one of lower temperature, but the reverse requires additional energy to be expended. Deploying a heat pump allows this process to occur, transferring warmth in a manner opposed to its natural flow. 

Basic Concept

The heat pump operates by consuming less energy (work) to move a given quantity of heat, hence its advantage over other heating methods like electric resistance heating, which typically requires substantially more energy.

Energy Transfer Ratio

To shift heat Q from a cooler exterior to a warmer interior, the amount of energy W needed can be expressed as:

  • Work Done (W): Represents the energy employed by the heat pump’s compressor.
  • Heat Moved (Q): The heat shifted from the colder zone to the warmer zone.
  • Coefficient of Performance (COP): A measure of the heat pump’s efficiency at the prevailing temperatures of the two regions involved.

The equation is given by:

W = Q / COP

The efficiency of a heat pump is significantly influenced by its COP, which is typically greater than one (can be 1:4), meaning that it needs less work to transfer heat compared to the amount of heat it moves. However, it’s important to note that the COP decreases as the higher-temperature environment’s temperature climbs, or the external temperature decreases, requiring more energy per unit of heat transferred.

Calculating Efficiency

Envision a heat pump working along the confines of the idealised reverse Carnot cycle:

  • Low-temperature reservoir: Situated at 270 K (-3°C)
  • High-temperature reservoir: The interior of a building at 297 K (24°C)

The kelvin (abbreviated to K), less commonly called the degree Kelvin (o K), is the Standard International ( SI ) unit of thermodynamic temperature.

Consider an air source heat pump scenario where the outside temperature is -3 degrees Celsius, equivalent to 270 Kelvin, and the inside temperature of a building is maintained at 25 degrees Celsius, equivalent to 298 Kelvin. The coefficient of performance (COP) of the heat pump is 4, meaning for every unit of energy input, the heat pump can transfer 4 units of heat energy.

Given this, we can understand how the heat pump operates. At -3 degrees Celsius (270 K), the heat pump extracts heat from the outdoor air and transfers it into the building. Since the COP is 4, for every unit of energy (e.g., electricity) the heat pump consumes, it can move 4 units of heat from the outdoor environment to the indoor space.

So, to raise the indoor temperature from 270 K to 298 K (25 degrees Celsius), the heat pump needs to transfer a certain amount of heat energy. With a COP of 4, it requires only 25% of the energy input compared to the amount of heat energy it transfers. In this case, the heat pump would effectively add heat to the indoor space, ensuring it reaches and maintains the desired temperature of 298 K (25 degrees Celsius).

Practical Considerations

It’s vital to be aware that the theoretical heat output may not always be achievable in practice. External factors, such as suboptimal placement of the unit where airflow is restricted, could deter performance. This is also an area where the different brands of heat pump will give a different performance output, so be sure to choose a brand with a good reputation and high performance figures.

Installation Stages of Air Source Heat Pumps


Air source heat pump installation is a structured process requiring a MCS qualified installer to evaluate, plan, and execute the setup. Below is an overview of what to expect during the installation stages.

Step 1: Evaluating Your Premises

The process kicks off with a professional assessment of your property to determine the heat pump’s optimal placement, considering factors like insulation levels, heat requirements, and radiator upgrades. A survey is sometimes done by a third party company for a fee, by outsourcing the survey, you can feel confident that you will get an impartial assessment of your home and heating requirements. Once your assessment is completed, the outcome of the survey will allow you to make an informed choice on the heat pump size, brand and radiator upgrade requirements, without the influence of a company that may not have your interests as their main priority.

Step 2: System Design and Quotation

Once your assessment is completed, the outcome of the survey will allow you to make an informed choice on the heat pump size, brand and radiator upgrade requirement.

The system design will include an estimation of the total cost, influenced by the size of the heat pump and the complexity of the installation.

Step 3: Implementing the Installation

With the design agreed upon, the actual installation can begin. The first step will be the draining down and removal of the existing system, usually existing pipework is kept in place if it is in good condition. The new heat pump, hot water cylinder and radiators are then installed with new wiring, the system is then filled up with water and ready to turn on.

Step 4: Certification and Functional Testing

On completion, pressure tests are conducted and a start up cycle to verify the heat pump system‘s operational functionality. Safe operation and electrical sign off have to be done before it’s fully handed over for your usage. You’ll receive key MCS certification and user guide documents with warranty information.

Cost-wise, an air source heat pump might entail an expenditure between £12,000 and £18,000, though this varies with several factors. However, by calculating savings over time, through reduced energy costs and financial incentives, such as the Boiler Upgrade Scheme, the initial investment can be efficiently recovered, and savings turbo charged if you combine with solar panels and smart energy tariffs! 

Government Grants for Heat Pumps


Boiler Upgrade Scheme

As part of the transition to greener energy, the UK government’s Boiler Upgrade Scheme means you could claim £7500 when you switch to a more efficient air source heat pump. You must own your property and having an older non-renewable heating system, this includes all fossil fuel systems, as well as electric boilers and storage heaters. To get access to the grant, you must be working with an MCS accredited installer and choose an approved heat pump model.

You can find a local heat pump installer by filling in your details with Compare Renewables.

Potential Reductions in Heating Expenditures

Upgrading to an air source heat pump can be cost-effective over time. These systems are known for their exceptional efficiency, boasting a coefficient of performance (COP) that can reach over 400% in efficiency. In simpler terms, an air source heat pump can provide up to four times the heat energy per unit of electricity it consumes, offering marked savings on your energy bills. This efficiency measure starkly contrasts with fossil fuel-based heating systems, such as boilers with efficiencies between 70% to 95%, equating to 0.7 to 0.95 in COP.

Considering factors like your current heating setup, property size, and the heat pump’s efficiency, the potential savings available for grabs could swiftly counterbalance the initial installation costs. With heating demands ever-increasing, air source heat pumps are setting the standard for the new super efficient, environmentally friendly and normal way to heat your home, which is a winning formula accross the board in our eyes.

Heat Pump Costs

Influencing Factors on Heat Pump Expenses

Acquiring a heat pump involves contemplating several key aspects that will affect the financial investment:

  • Home Dimensions: The larger your residence, the larger the heat pump will need to be, which does have a cost increase incrementally. Yet, selecting the right size heat pump is important, it needs to be large enough for your needs, but not vastly oversized. A heat pump should be oversized by around 10% to 30%, as this will allow for changes in the home over time, but ensure the pump is not too big, which would incur unnecessary higher running costs. 
  • Heating Demands: Your household heating demands as also as important as the size, these are shaped by the insulation levels of the walls, roof, floor and windows. The greater the insulation levels will mean a smaller system is required, which will save on upfront installation costs and also long term running costs. 
  • Pump’s Brand: Top tier brands may command a premium price; however, they can offer superior quality and efficiency and although there could be a higher initial price, the return on investment will pay for itself through your reduced heating bills. Brands like Mitsubishi, Vaillant & Samsung offer good quality heat pumps and are known for their reliability.
  • Efficiency Rating (CoP): Pumps with a higher Coefficient of Performance (CoP) deliver better efficiency, but also note that the COP will vary depending on the flow temperature of the water in the system, if you are comparing systems, ensure you compare the COP at 50 degrees.
  • Renovation Expenditures: Should insulation be needed to keep your house warm these should be added to the total cost, there may also be some new radiators required when upgrading to a heat pump. New radiators are needed to make sure the rooms heat up as fast as possible which will reduce running costs.

Estimated Costs for Air Source Heat Pump Installation

When adding up the costs of an air source heat pump, the upfront costs are softened because you should qualify for the Boiler Upgrade Scheme voucher, which is a sizable contribution of £7,500.

Air Source Heat Pump Cost

Single Air-to-water heat pump setups come in around 4 or 5 different sizes per brand, from 5kw up to 17kw. The smaller and thermally sound houses need a smaller heat source pump, the bigger and older houses usually need a large heat pump to keep their home warm, which usually incurs a bigger price tag. The heat pump prices below are before the £7500 voucher has been taken off, and include some radiator upgrades.

  • A Smaller House / Good insulation: Expect heat pump installation costs between £12,000 and £15,000. (£4500 to £7500 to pay when using the grant)
  • A Large House: Heat pump costs can be between £13,500 and £18,000. (£6000 to £10,500 to pay when using the grant)
  • Annual Upkeep: On average £150 – £250 for annual servicing, this is required to keep warranties valid.

Upkeep and Handling of Air Source Heat Pumps

To guarantee optimal performance and extend the lifespan of your air source heat pump, appropriate upkeep is vital. Here are streamlined strategies to maintain your system effectively:

  • Routinely Check the exterior unit and remove any debris that could impair the fan blades.
  • During winter, prevent snow and ice from amassing on the unit to avoid damage, a little bit would be fine, but if there was heavy snowfall you would need to create space for airflow 1m around it.
  • Check the refrigerant and anti-freeze levels – this is to be done on the annual service, but the refrigerant levels shouldn’t change in most systems, the anti-freeze may need topping up.
  • Schedule a yearly service to verify all components, including the compressor and heat exchanger, are in good condition with no leaks or faults. Your installer might offer a service plan when you purchase the system.

Just using a little bit of common sense and caring for your air source heat pump system like you would with outher parts of your home reduces the need for repairs and assures the system is operating efficiently. A heat pump by design needs less maintenance than almost all other types of heating system, but with little extra effort, they are also extremely reliable.

Comparing Air Source Heat Pumps with Conventional Heating Methods

Air Source Heat Pumps vs Gas Boilers

Gas boilers, traditionally common in british homes, utilise natural gas to create heat. In comparison, air source heat pumps are a more efficient alternative by extracting warmth from the outside air.

Both offer their own set of benefits and considerations. This is the first of 3 system comparisons, so let’s compare these heat pumps vs gas boilers to help you make an informed decision for your home.

Installation Costs:

Air source heat pumps typically involve higher upfront costs compared to gas boilers. Although the installation costs are high, the Boiler Upgrade Scheme can help offset these costs, making air source heat pumps a more financially viable option and bringing them to a level where they are an attractive option against a gas boiler.

Gas boilers, on the other hand, generally come with lower installation costs. The equipment is often more affordable, and installation is relatively straightforward for homes already connected to mains gas. However, it’s important to consider potential future regulations, such as the upcoming ban on gas boilers in new homes from 2025 and the phasing out of gas boilers over the proceeding 10 years.

Running Costs:

Despite the higher upfront costs, air source heat pumps offer significant savings in running costs over time. They are highly energy efficient, meaning they can provide 4 to 5x more heat energy per unit of electricity consumed compared to gas boilers. This results in lower energy bills and long-term cost savings for homeowners.

Gas boilers have historically been favored for their relatively low running costs, especially in areas where natural gas is readily available. Gas boilers are the cheapest of all the fossil fuel systems that could heat your home. However, fluctuations in gas prices over time can impact their affordability over the longer term. 

Carbon Footprint:

After manufactuing an installation, air source heat pumps can have no carbon footprint compared to gas boilers. This is because they rely on electricity rather than burning fossil fuels for operation. As the UK continues to transition towards renewable energy sources, the environmental benefits of air source heat pumps are expected to increase further.

Gas boilers are a major source of carbon emissions in residential heating systems, according to GOV.UK, over 38% of the UK’s gas usage is for heating homes. Burning natural gas releases carbon dioxide and other pollutants into the atmosphere, contributing to air quality issues and environmental concerns. With the UK government’s commitment to achieving net-zero emissions, air source heat pumps are their chosen heating system to help achieve their net-zero goals.

In conclusion, while both air source heat pumps and gas boilers offer heating solutions for homes, air source heat pumps are the stand out winner for their energy efficiency and lower carbon footprint. 

See our extended review of Air Source Heat Pumps vs Gas Boilers.

Air Source Heat Pumps Vs Oil Boilers

Our second heat pump comparison is with oil boilers. Oil boilers operate similarly to gas boilers but use oil as a fuel, making them less favourable where a gas supply is unavailable. 

Installation Costs:

We already know air source heat pumps typically involve higher upfront costs compared to oil boilers. However with the  Boiler Upgrade Scheme offsetting the costs, there will be between £4500 to £10,500 to pay.

Comparing this to oil boilers on the other hand, generally come with supply and installation costs that range from £4000 to £12,000. The equipment is often in the same price range, but with fossil fuels being phased out, oil systems are set to become rarer with installations and parts becoming more expensive.

There is also a need for an oil tank which can cost £1500 to £5000 if you dont already have one installed. Just like with mains gas, there is the potential of environmental regulations regarding oil heating having a negative effect too.

Running Costs:

Heat pumps offer significant savings in running costs over time, especially if you can compine them with cheap or free electrcity from solar panels. The efficiency of oil boilers is comparable to that of gas boilers, but they suffer from a greater price volatility in the oil market oil and a more significant environmental impact. 

Oil boilers have historically been favored by residents who are off the mains gas network, this is due to oil being the fuel that provides the lowest running costs available to them, which is the best of bad bunch situation. However, oil prices over time are significantly higher than mains gas and even more higher than a heat pumps electricity requirement, which makes oil on par with bottled gas, as the worst choice of fuel based on the ongoing running costs.

Carbon Footprint:

As covered already, air source heat pumps have no carbon footprint, when compared to oil boilers there is only one winner. Oil boilers are a significant source of carbon emissions, burning oil releases carbon dioxide and other pollutants into the atmosphere, contributing to air quality issues and environmental concerns. It is likely that oil boilers will be outlawed in the not too distant future.

In conclusion, while both air source heat pumps and oil boilers offer heating solutions for homes, air source heat pumps are the clear winner across the board, the installation costs are comparable and from a running cost and environmental point of view, an air source heat pump is the winner by a mile.

Air Source Heat Pumps vs Electric Storage Heaters

Our third and final comparison is heat pumps vs storage heaters. Electric storage heaters are seen in properties without access to gas and use off-peak electricity to store heat for release during the day.

Installation Costs:

Air source heat pumps typically involve higher upfront costs compared to electric storage heaters. There is no need for a wet system and expensive copper piping, plus lower labour costs, although they are still not the cheapest system to install. 

The cost of a system will range from an average of £250 to £800 per radiator, which means a system with 10 radiators could cost £2500 to £8000. In comparison a heat pump is in the range of £4500 to £10500, which means there will be some situations when a heat pump could be cheaper, but most houses a heat pump is likely to be the higher cost. A good measure would be if there is 15 radiators in a house, a heat pump is likely to be cheaper, however for a smaller house, the initial cost of storage heaters will be less.

Both systems are powered by electricity so there is no supply issues or variances in cost for this aspect of the installation.

Running Costs:

Despite the higher upfront costs, air source heat pumps offer significant savings in running costs over time. Giving at least 4x efficiency over storage heaters and with both systems are running on eletricity, that means a heat pump will be 4x times cheaper to run than storage heaters.

There could be a slight variance in those figures depending on what your day and night time electricity tariffs are, plus if your home has solar panels installed, which would favour air source heat pumps. This is because the solar panels will provide free electricity in the day time, which in turn will give you free heat.

Electric storage heaters typically have  inefficiencies in heat retention. They often require charging during off-peak hours when electricity tariffs are lower, but may struggle to retain heat effectively throughout the day, resulting in unnecessary higher energy consumption and associated costs with day time electricity.

Carbon Footprint:

Air source heat pumps have a lower or equal carbon footprint in comparison with electric storage heaters. This is because both systems rely on electricity rather than burning fossil fuels for operation. 

As both systems use electricty, they could be carbon neutral, providing the electrcity is generated from a renewable source. However a heat pump uses 4x less electricty, as the UK still has fossil fuel power stations for electricty generation, it does position storage heaters behind air source heat pumps from an environmental point of view.

In conclusion, while both air source heat pumps and electric storage heaters offer electric heating solutions, air source heat pumps stand out for their energy efficiency and carbon footprint, they are also simliar on installation costs, which means overall heat pumps are the better choice for as the best heating system.

Heat Pumps vs Boilers vs Storage Heaters

This master table provides a side by side comprehensive overview of the key differences between air source heat pumps, gas boilers, oil boilers, and electric storage heaters.

AspectAir Source Heat PumpsGas BoilersOil BoilersElectric Storage Heaters
Installation CostsHigher upfront costs, but with government incentives to offset expenses.Lower upfront costs, particularly if your home is already connected to mains gas.Average upfront costs, with extra to pay if your home doesn’t have an oil tank already.Average upfront costs, but no wet system in place if you switch to another type.
Running CostsBest energy efficiency, long-term savings on energy bills, can combine with solar panels.Lowest of the fossil fuel running costs, no way to combine with solar panelsHistorically unstable running costs due to fluctuations in oil prices.Highest running costs due to being very inefficienct.
Carbon FootprintLower carbon emissions due to reliance on electricity rather than burning fossil fuels.Higher carbon emissions from burning gas.Higher carbon emissions from burning oil, plus inefficient delivery by roadLower carbon emissions, depending on the source of electricity generation.

The outcome is that overall, air source heat pumps represent a significant step forward in heating, from an financial and environmental point of view, the heating landscape is changing to a renewable one, although the costs are higher initially, the long term view shows that air source heat pumps are the clear winner. If you are struggling to pay for the heat pump up front, a lot of installers offer finance plans, which although paying interest doesn’t sound appealing, your savings over time should outweigh the interest payments and long term savings in comparison to other heat sources.

Air Source Heat Pumps For The Environmental

Annual Carbon Emissions

It is known that traditional heating systems have a considerably high carbon footprint. To offer contrast, let’s look at a comparative analysis:

Based on average household consumption a study has shown how many kilograms are emitted per heating system:

Gas Boilers – 2720kg

Oil Boilers – 5240kg

Air Source Heat Pumps – 780kg (if the electrcity is generated from fossil fuels) or 0kg (if electricity is sourced from renewables)

Just to put this into perspective, the 5240kg of Co2 emissions is enough power to charge a smartphone 620,0oo times, or 2600 litres of diesel consumed by a car.

If the nation could switch over to an air source heat pump (ASHP) on each property, the UK would see a drastic decrease in carbon emissions, especially if the electricity powering it comes from renewable sources like solar PV & wind farms, effectively cutting emissions to zero. Besides being a huge part of moving towards a net-zero country, renewable technologies also give bill payers economic benefits over the long term.

Innovative Refrigerants and Their Significance

Recent advancements, such as the introduction of R32 and R290 refrigerants in heat pumps, hold high hopes for even better environmental outcomes. R32, having a lower global warming potential (GWP) than its predecessors, presents a stride towards more ecological heating systems. R290, or propane, is notable for its negligible GWP, enhancing the eco-friendly credentials of ASHPs.

The R32 refrigerant has a GWP of 675, and the R290 heat pumps have a GWP of 657, which is important, by 2025 all refrigerants with a GWP of over 750 are being phased out of use. These refrigerants used in todays heat pumps are essential for longevity in new green heating solutions

Frequently Asked Questions

How Do Air Source Heat Pumps Get Warmth

Air source heat pumps absorb heat from the atmosphere and intensify it to warm your residence and water supply. The operation is analogous to a refrigerator but in reverse, drawing in air, even at temperatures as low as -25°C, to maintain a comfortable indoor climate throughout the year.

What Are The Benefits Of Getting An Air Source Heat Pump?

Opting for an air source heat pump can bestow multiple benefits:

  • Exceptional energy efficiency, potentially reducing heating expenditure
  • Provision of both heating and hot water
  • A pathway to a carbon-neutral operation given the use of electricity over fossil fuels
  • Eligibility for financial incentives like the Boiler Upgrade Scheme

What is the Cost To Install An Air Source Heat Pump?

Investing in an air source heat pump entails costs affected by your home’s scale, installation intricacy, and the chosen model. While prices typically span from £12,000 to £18,000, government contributions of up to £7500 can significantly mitigate the expense.

What Is The Difference Between Air-to-Water and Air-to-Air Systems?

Differentiate between two air source heat pump models:

Air-to-water systems: Integrate with water-based heaters like underfloor setups or radiators, providing central heating and hot water.

Air-to-air systems: Directly warm your home’s air, suitable if you have an existing network of fans or ducts but ineligible for the Boiler Upgrade Scheme.

Is a Mitsubishi Ecodan Heat Pump Good?

The Mitsubishi Ecodan is a great heat pump, it excels in reliability and efficiency, it comes with the melcloud control app and a 1:4 heating efficiency ratio at 50°C output temperature. It is once of the best heat pumps you can buy and is available for a range of property sizes.

Should I Get An Air Source Heat Pump or Conventional Heating System?

Air source heat pumps surpass traditional heaters in energy efficiency and environmental friendliness, providing heat transfer from ambient air, thus trimming your bills and carbon footprint. They future-proof your home, ready for upcoming regulations disallowing fossil-fuel-derived heat in new homes post-April 2025.

Does Solar Panels Work With Air Source Heat Pumps?

Adopting an air source heat pump is a stride towards sustainability, particularly when allied with solar photovoltaic (PV) panels and battery storage, cementing an eco-friendly, self-sufficient home energy system.

Discover our complete guide to solar panels for complementary sustainable energy solutions.

solar panel house diagram, cost of solar, how do solar panels work

How Do Solar Panels Work?

Solar panels have become a familiar sight in our communities, adorning the roofs of buildings and according to MCS certified, 1.3 million homes in the UK. Despite their prevalence, many still ponder the mechanics behind their functionality. In essence, solar panels harness sunlight and transform it into electricity through specialized structures known as ‘photovoltaic cells’ within the panels. These cells ingeniously generate an electrical current that can be utilised within our households.

This solar technology not only provides a renewable energy source but also a clean one, offering an alternative to traditional fossil-fuelled power. By reducing carbon emissions and curbing the escalating costs of energy, solar panels are becoming a must-have asset for both the environment and homeowners. In this article, we will delve deeper into the inner mechanics of solar panels, explore their components, and weigh the advantages and disadvantages of solar energy for our planet.

How Solar Panels Work

Solar panels, also known as photovoltaic (PV) panels, convert solar energy into usable electricity. The number of solar panels installed on a rooftop determines the amount of electricity generated. Here is a step-by-step guide on how solar panels work:

  1. Solar panels consist of metal sheets inside a glass casing that contain a series of cells known as photovoltaics (PV). PV cells are made of a thin, semi-conductive material with two silicon layers. One layer is positively charged, and the other is negatively charged, creating an electric field. When sunlight hits the PV solar cell, it causes motion within the electric field, generating an electrical current.

  2. Once the electric current is generated, it can be redirected from the solar panels. At this point, the electricity produced is in a form known as a direct current (DC), and for us to use this on our electrical devices at home, it needs to be converted to an alternating current (AC).

  3. To convert DC electricity to AC, a solar inverter is used. An inverter is an important part of a solar power system, in british temperatures it is best to install them inside the house, but there are inveters desgined to be outdoors if needed. In home systems, there are Three types of inverters: a ‘string inverter’ (a central inverter), a hybrid inverter or micro-inverters. Micro-inverters are used only on individual solar PV panels and are not likely to be seen in larger systems. A string inverter will be used for most home setups requiring multiple solar panels. This is so-called because each solar panel is wired into a central inverter (much like a series of strings coming together). A hybrid inverter does the same job as a string, but allows a battery to be coupled up and charged by the solar system. In 2024, hybrid inverters are the most popular choice amongst the british public due to the increased financial benefits of having solar storage batteries.

  4. In some modern models, the inverter can also be used as a point to monitor your power generation and usage levels. Depending on the model, you can access these details online or through an app.

  5. From here, you now have a usable source of electricity that can power your home. Three things can happen next – you can use the produced electricity or store any that you don’t use in a solar battery. If at any time you are generating more than what you are using, you can automatically sell back electricity to the grid using the smart export guarantee (SEG)

It’s important to note that solar panels are most effective in direct sunlight, but they do still work on cloudy days. Although the efficiency of solar panels decreases in cloudy conditions, they can still produce about 10-25% of their rated capacity, depending on the thickness and density of the cloud cover source.

Since 2020, homeowners in England, Scotland, and Wales have been able to receive payments for each renewable energy unit they produce and export to the grid under the Smart Export Guarantee source. 

In conclusion, solar panels work by converting solar energy into usable electricity through a series of PV cells, inverters, and batteries. They are an effective and sustainable way to generate free electricity and reduce your carbon footprint.

The Different Types of Solar Panel

Monocrystalline or Polycrystalline?

When choosing solar panels, you will come across different types of solar panel materials. The two main types are monocrystalline & polycrystalline, with thin film panels not used much anymore. Each type has its own advantages and disadvantages, depending on your needs, budget, and space.

MonocrystallineHigh efficiency up to 30%, long lifespan, takes up less spaceMore expensive 
PolycrystallineLower cost than monocrystalline, average efficiency up to 22% Lower efficiency than monocrystalline, takes up more space
Thin-FilmLeast expensive, flexible and lightweight, works well in low light conditionsLower efficiency, shorter lifespan

What Are Solar Thermal Panels?

The most popular solar panels are photovoltaic, which are electricity producing panels, however solar thermal panels use sunlight to generate heat which can be used for your central heating system and hot water needs. Although both are utilising solar energy, solar thermal panels do have a use for some homes and businesses, but the disadvantage is that solar thermal power cannot be coverted in to electrical power, unlike solar PV. Electrical power can be used for your basic electrci needs, but also used for heating too when conbined with an immersion water heater, or an air sourced heat pump.

How Long Do Solar Panels Last?

The lifespan of solar panels depends on the type of panel and how well they are maintained. Monocrystalline panels have the longest lifespan, usually 25 years or more. Polycrystalline panels have a lifespan of 20-25 years, while thin-film panels have a lifespan of 10-15 years. Proper maintenance can extend the lifespan of your solar panels. This includes cleaning every year or two, checking for damage, and ensuring that the panels are operating at maximum efficiency, which you can do through a mobile app on most new systems.

In conclusion, when choosing solar panels, you need to consider the type of panel material, whether you need solar PV or solar thermal panels, and the lifespan of the panels. By understanding these factors, you can make an informed decision and choose the solar panels that are right for your needs.

How to Choose the Best Solar Panel System for Your Home?

Choosing the best solar panel system for your home is not the easiest thing to decide on. However, our website www.comparerenewables.com makes it easy for you to find MCS accredited solar installers. Simply fill in your details and receive quotes from trusted installers. When choosing a solar panel system, consider the following factors:

  • Your budget
  • Your roof space
  • Your energy & battery
  • The efficiency of the panels
  • The warranty offered by the manufacturers

An expert will come out to see you and provide a detailed quote. Don’t hesitate to ask questions and compare quotes before making a decision.

Take a look at our guide on the costs involved to install a solar system in your home.

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How Does a Solar Battery Work?

Storing Energy

Solar batteries store energy generated by solar panels that is not immediately used. This stored energy can be used during periods of low solar generation, such as at night or on cloudy days. The process of storing the energy involves converting the stored direct current (DC) electricity produced by the solar panels into alternating current (AC) electricity that can be used in your home. This is done through the use of a hybrid solar inverter, which also manages the charging and discharging of the battery.

Are Solar Batteries Worth It?

The cost of solar batteries has decreased in recent years, making them a more affordable option for homeowners. However, the cost-benefit analysis of installing a solar battery depends on a variety of factors, including your energy usage, the size of your solar panel system, and your location. In areas with high electricity rates or frequent power outages, solar batteries can provide significant savings from your electric bill as well as peace of mind. Additionally, solar batteries allow you to operate your home on a fully renewable energy source, reducing your carbon footprint.

Using my experience I have found that solar batteries can be a valuable addition to a solar panel system, providing backup power and reducing energy costs. The best way to calculate the right battery size for your home is to look at you annual usage, divide by 365, to get your daily usage, then get a battery that is between 30% to 50% of you annual consumption, that should be enough to cover you at night and on days of low light. However, it is important to carefully consider your individual circumstances and remember, capturing all of your solar electrcity is not the aim here, you want enough batteries for the average day, not your highest day of consuption, because you will not get a good return on investment on that extra battery which be used on a few days per year.

Growatt Hybrid inverter solar battery 3.3kwh solar panels, solar installer

Advantages of Having Solar Panels at Home

Installing solar panels at your home comes with a wide range of benefits. Here are some of the advantages that you can enjoy:

  • Saving Money: By installing solar panels on your roof, you can produce your electricity supply, which means you no longer need to rely on a grid supplier for the majority of your consumption. This can significantly cut down your electricity bills. The only electricity expenditure you need to consider is if you use the grid during the night and the standing charge.

  • Reducing Your Carbon Footprint: Solar panels are one of the best steps you can take if you’re looking for a way to go green and cut down harmful emissions. Most electricity suppliers use fossil fuels such as oil, gas or coal to produce power, which creates harmful carbon dioxide. On the other hand, solar power is a clean, non-polluting, renewable energy source that is also free!

  • Becoming Independent from the Grid: The National Grid provides most people with electricity, fuel prices are prone to sharp, unstable price changes. By switching to your supply, you can become less dependent on the grid and know that you have a consistant power supply from solar panels.

  • Low Maintenance: Solar panels have a long lifespan of at least 25-30 years and come with average warranties of around 20+ years, meaning you don’t have to worry about expensive replacements or constant upgrades.

  • Earning Money: Through various incentives and schemes, homeowners with solar panels may be able to receive payments for any excess electricity through more recent export tariffs. This helps significantly in recouping the cost of the installation, making it an even more lucrative  long-term investment.

Do Solar Panels Work in Bad Weather?

It is a common misconception that solar panels only work on hot and sunny days. However, solar panels can still generate power in almost any type of weather, including cloudy days, rain, and even snow. The only difference is that they won’t produce as much as they would on a brighter day.

On severely overcast and cloudy days, your solar panels’ power output will be impacted if the cloud cover lasts most of the day. One way to determine if your solar panels are getting any sun is to check for shadows outside. If shadows are being produced, your panels will likely get some sunlight. No shadows would suggest the clouds are too thick for any sun to get through.

It is important to understand your unique solar panel setup, especially before you purchase, such as your location, the type of panels, and how you will source electricity should your supply drop in cloudy weather and in the evening. The best way to improve solar panel performance in bad weather is to use a battery storage back up system, which will store excess energy for use during periods of low production or bad weather. 

How much do solar panels cost?

The cost of solar panels depends on various factors such as the size of your home and the number of panels you need. Typically, solar panel systems cost between £5,000 – £15,000. The size of the system is measured in kilowatts (kWp), and the cost of a 4kWp system, which is the average size for a UK home, is around £8,000. If you add a hybrid inverter on and a battery storage, you can expect to pay an extra £3,000 and upwards, depending on the amount of battery storage which you require.

We have a guide to find out which system will be best for your home – How Many Solar Panels Do I Need?

By generating your own electricity, you can reduce your dependence on the grid and save money on your electricity bills. We recommend speaking to professionals to get the best idea of how much solar panels cost. By getting multiple quotes from qualified installers, you can get trustworthy advice and find the best prices simultaneously!

black solar panels, on a bungalow, solar power, monocrystalline, buy solar panesl

How to Choose a Solar Panel Installer

Choosing the right solar panel installer is crucial to ensuring that your solar panel system is installed correctly and efficiently. Here are some tips on how to choose the best solar panel installer for your needs:

  1. Look for an installer who is MCS accredited. This means that they have been vetted and approved by the industry standard body for renewable energy installers in the UK.

  2. Get quotes from at least three different installers. This will allow you to compare prices and services and choose the one that best fits your needs.

  3. Check customer reviews and references. Look for reviews and testimonials from previous customers to get an idea of the quality of service that the installer provides.

  4. Make sure the installer offers a warranty on their work. This will give you peace of mind knowing that if anything goes wrong with your system, the installer will be there to fix it.

  5. Consider financing options. Many installers offer financing options to help you spread the cost of your solar panel system over time. You will also get cover using the FCA section 75 rule.

By following these tips, you can ensure that you choose the best solar panel installer for your needs and get the most out of your solar panel system.

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4 Ways To Make Money With Solar Panels 

Using Electricity From Your Solar Panels

Instead of relying solely on electricity from the grid, your solar panels produce their own power, reducing the amount of electricity you need to purchase from the utility company and saves you money for every kWh.

Store Energy in Your Battery to Use at Night

Solar panels work only work during daylight hours, meaning they become useless when it’s dark. This doesn’t just mean nightfall; in low light days through the winter, they won’t produce as much electricity as in good conditions. Installing a solar storage battery to store the excess energy generated during the day for use at night. This prevents you from having to buy electrcitiy from the grid at night time and is a great way to maximise the return on your investment.

SEG Payments

The Smart Export Guarantee (SEG) is a government scheme that pays you for the excess electricity you generate and export to the grid. This means that you can earn money from your solar panels even when you’re not using the energy yourself. The SEG payments are made by energy suppliers and are based on the amount of energy you export. The rate you receive will depend on your supplier, so it’s worth shopping around to find the best deal.

Overnight Charge Your Battery on the Cheap Rates

If you have a solar storage battery, you can charge it overnight during off-peak hours when electricity rates are cheaper. This means that you can use the stored energy during peak hours when rates are higher, maximising your savings and return on investment. 

In conclusion, by using a combination of SEG payments and solar storage batteries, you can maximise your return on investment with an optimal setup. However, it’s important to choose a trusted installer and consider all factors before investing in solar panels.

Solar Panel Rules & Regulation

The Microgeneration Certification Scheme (MCS) is the governing body when It comes to installation standards and good practice. All installers who claim to have a level of competency should be registered with the MCS to evidence their quality. The only other main area of external influence is with your local Distribution Network Operator, who will have an input on what system you are able to have at your home. 

G98 or G99 Application

When installing solar panels in the UK, a notification must be made to the energy grid. This notification is called a G98 or G99 application, depending on the size of the system. Installers will usually handle this process for you, but it’s important to understand what each application entails.


A G98 application is required for solar panel systems with an inverter size of less than 3.68kW. This application process is relatively straightforward and involves notifying your local District Network Operator (DNO) within 28 days of commissioning the system. Once the DNO receives the notification, they will review the application and confirm that the system meets safety and technical standards.


If your solar panel system has an inverter size of more than 3.68kW, you will need to submit a G99 application. This process is more complex than a G98 application and requires a more detailed review by your DNO. The purpose of the G99 application is to ensure that your solar panel system is safe and won’t cause any disruptions to the energy grid.

The G99 application process involves submitting detailed technical information about your system, such as its maximum export capacity and fault ride-through capability. The DNO will review this information and may require additional testing or modifications to ensure that your system meets all safety and technical standards.

Once your G99 application is approved, you will receive a connection agreement from your DNO. This agreement outlines the terms and conditions for connecting your solar panel system to the energy grid and may include requirements for ongoing maintenance and monitoring.

It’s important to note that the G99 application process can take several weeks or even months to complete, so it’s important to plan accordingly and work closely with your installer to ensure that all requirements are met.