Are Heat Pumps Really Zero Emissions?

Heat pumps have gained a lot of attention for being a more environmentally friendly way to heat homes compared to traditional gas or oil boilers. But the question remains: are they truly “zero emissions”? The short answer is that heat pumps significantly reduce emissions, but they aren’t completely emission-free. However, the overall impact is far lower than most conventional heating systems.

How Heat Pumps Work and Why They’re Eco-Friendly

To understand why heat pumps are seen as a low-emission option, let’s revisit how they operate. A heat pump doesn’t generate heat by burning fuel like a gas boiler. Instead, it moves heat from the air, ground, or water outside your home and transfers it inside to warm your living space and heat water. If you want to know more detail, check out our guide to how heat pumps work.

Since it’s not combusting fuel, there are no direct emissions from the system itself—no carbon dioxide (CO2) is released while the heat pump is running. This makes heat pumps far cleaner compared to fossil fuel-based heating systems.

The Role of Electricity

Heat pumps do require electricity to run, which is where emissions can come into play. If the electricity powering your heat pump comes from fossil fuels, such as coal or natural gas, then there are indirect emissions associated with your heating system. However, the good news is that heat pumps are extremely efficient, often delivering three to four units of heat for every unit of electricity they consume.

This efficiency means that even when powered by non-renewable energy, heat pumps produce fewer emissions than systems that burn fuel to create heat. And as more electricity grids incorporate renewable energy sources like wind, solar, and hydropower, the emissions associated with running a heat pump continue to drop.

Can Heat Pumps Be Zero Emissions?

Heat pumps have the potential to be zero emissions, but this depends largely on where the electricity comes from. If your home or grid is powered by 100% renewable energy—such as solar panels, wind power, or green energy providers—then your heat pump system can be truly zero emissions. Here’s how this works:

1. Renewable Electricity: When your heat pump runs on electricity from renewable sources, no CO2 or other harmful emissions are produced. In this case, your heating is not only highly efficient but also emission-free.
2. Grid Decarbonisation: Many countries, including the UK, are moving towards greener electricity grids, meaning the amount of renewable energy feeding into the system is increasing. As the grid becomes cleaner, the emissions associated with heat pumps will continue to decrease, even for those who don’t have their own renewable energy sources.

The national grid even publishes the emissions intensity of the grid, you can check out their interactive dashboard here.

Comparing Emissions: Heat Pumps vs. Traditional Systems

When comparing heat pumps to traditional heating systems, the emissions savings are clear:

• Gas Boilers: A typical gas boiler produces about 0.20 kg of CO2 for every kWh of heat it produces. This is because gas boilers burn natural gas to generate heat, which directly emits carbon dioxide
• Oil Boilers: Even more polluting than gas boilers, oil boilers emit around 0.26 kg of CO2 per kWh, depending on the efficiency of the system and the type of heating oil used
• Heat Pumps: In comparison, a heat pump powered by the national grid in the UK produces around 0.15 kg of CO2 per kWh (this was the average carbon intensity of the national grid in 2023). However, with renewable electricity, this figure can drop even further - particularly on windy or sunny days

‍Why Heat Pumps Are a Key Part of the Low-Carbon Future

The fact that heat pumps drastically reduce emissions, even when powered by standard electricity grids, makes them a cornerstone of the low-carbon future. As governments and homeowners push for greener energy solutions, the benefits of heat pumps are only set to increase.

Not only do they help reduce carbon footprints, but they also future-proof homes. As electricity grids continue to decarbonise, heat pumps will become even cleaner without homeowners needing to make any changes to their systems. This contrasts with gas or oil boilers, which will always produce CO2 no matter how efficient they are.

FAQs About Heat Pumps and Emissions

Do heat pumps produce any emissions directly?

No, heat pumps don’t burn fuel, so they don’t produce direct emissions like CO2 or other pollutants. However, the electricity they use can create emissions depending on its source.

How efficient are heat pumps?

Heat pumps are extremely efficient. For every unit of electricity they use, they can deliver three to four units of heat, which means they’re much more efficient than conventional boilers.

Can I make my heat pump zero emissions?

Yes, if your heat pump is powered by renewable energy sources, like solar panels or wind power, it can operate with zero emissions. Alternatively, you can switch to a green energy provider that supplies renewable electricity.

Is a heat pump better for the environment than a gas boiler?

Absolutely. Heat pumps significantly reduce carbon emissions compared to gas boilers, especially when powered by renewable energy. Even with a conventional power grid, heat pumps still generate much fewer emissions due to their efficiency.

Are heat pumps part of the government’s plan to reduce emissions?

Yes, many governments including those in England, Wales and Scotland are promoting heat pumps as part of their strategy to lower carbon emissions and meet the UK’s net zero climate goal. Incentives and grants are often available to encourage homeowners to switch to heat pumps. For example the Boiler Upgrade scheme in England and Wales offers homeowners £7,500 as a grant if you chose to upgrade to a heat pump. Use our simple eligibility checker to find out if you could access this grant. The Scottish government also has a very similar scheme in place.

What can I do to further reduce emissions with a heat pump?

To further reduce emissions, consider switching to a renewable energy provider, or, if possible, install solar panels and a battery to power your heat pump. Regular maintenance also ensures that your system operates at peak efficiency, minimising energy waste.