What are heat pumps and why does the British government want to promote them? | Energy Efficiency | Guardian

2021-11-18 08:43:39 By : Ms. Cherry Huang

Their use can help the UK achieve its climate goals, but there are concerns about high installation and operating costs

Last modified on Tuesday, October 19, 2021 07.46 EDT

The government has made plans to provide a grant of £5,000 over the next three years to help 90,000 households install domestic heat pumps and other low-carbon heating systems as part of its plan to reduce Britain’s dependence on fossil fuel heating.

With the phasing out of gas boilers, by the 2030s, heat pump installations may reach 600,000 units per year-but is the UK ready for the home heating revolution?

In simple terms, the working principle of an electric heat pump is like a reverse refrigerator, extracting heat from the outside air, the ground or nearby water sources, and then concentrating and transferring the heat to the room. They can usually be found outside the home, and they look like a standard air conditioner.

Approximately 85% of British households use gas boilers for heating, making it one of the most polluting sectors in the economy. The fossil fuels used in our homes for heating, hot water and cooking account for more than one-fifth of the UK’s carbon emissions, which means that low-carbon alternatives are essential if the UK wants to meet its climate goals.

The price of a heat pump is usually several times that of a gas boiler. Air source pumps start at 6,000 pounds, and ground source pumps start at least 10,000 pounds. With more installations, prices are expected to plummet in the next few years. At the same time, the government's £5,000 grant should help bridge the cost gap.

But there are still people who worry about the operating cost of heat pumps, which in some cases may be 50% higher than gas boilers, because electricity costs include carbon taxes and subsidies to support low-carbon energy projects. Green groups are calling on the government to transfer these taxes and fees to gas bills, which will make electricity cheaper and help encourage households and businesses to abandon fossil fuels.

A properly installed heat pump has a size suitable for the property and should maintain a moderate indoor temperature. They are designed to maintain a stable temperature in the indoor space through gentle replenishment throughout the day, rather than rapidly heating up fossil fuels like traditional gas boilers. Therefore, they are very popular in Nordic countries where winter temperatures are much lower than those of the United Kingdom.

Heat pumps work best in homes with properly insulated windows, walls, and roofs. Using a certified heat pump installer is a key step in getting the best advice to ensure that your home does not leak too much heat and there is enough space to install a suitable heat pump.

If you have enough outdoor space, you can consider using a ground source heat pump, which requires a 100m borehole nearby. If the space is small, the air source heat pump can be placed directly outside the home, and the noise should be as loud as the refrigerator. Both of these options require a cabinet for the indoor water heater.

The government also provides funds to support other forms of low-carbon heating. Many companies responsible for the production and transportation of fossil fuel gases are eager for the UK to adopt hydrogen as an alternative. Early trials and plans are underway to test whether this can be done safely.

At the same time, one of the fastest-growing low-carbon options is district heating, which works well in cities where commercial real estate and apartment buildings can be connected to the same public heating network. In southeast London, the Swedish utility Vattenfall plans to collect heat from a waste incineration plant in Bexley to heat 21,000 homes. Heat from nearby factories, even abandoned mine shafts and geothermal sources may also play a role.