Changing the way we heat our homes: Hybrid Heat Pumps

Introducing hybrid Heat Pumps :eyes:

Hybrid heat pumps are part boiler and part heat pump

This hybrid heating setup uses a combination of energy from an air source :wind_face: heat pump and a boiler. It monitors the temperature :thermometer: outside and switches between energy sources depending on which is most efficient to warm your home :houses:. The heat pump provides most of your heating, and the boiler is used to meet peak demand in winter :snowflake:.

We need hybrid heat pumps if we’re to reach net zero by 2050

The UK has a legal obligation :writing_hand: to be net zero by 2050. As homes account for 15% of greenhouse gases, it’s important to find ways of decarbonising UK homes and reducing reliance on fossil fuels.

While heating in the UK is dominated by gas, electric options such as heat pumps are among the technologies :man_technologist: :woman_technologist: that can help us decarbonise homes. However, electrification of heat has the potential to increase grid congestion and costs :money_with_wings: at an energy system level. For some large, hard to insulate homes, they could also be too expensive. The Climate Change Committee (CCC) suggests hybrid heat pumps, where the bulk of heat demand is met by electricity, and peak demand is met by hydrogen, biomethane, or some natural gas.

Benefits of hybrid heat pumps :heavy_check_mark:

  • Flexible - hybrid pumps can switch quickly between gas and electricity. Making sure your house is heated at the cheapest times of the day is important for energy savings and avoiding grid congestion.
  • Better energy efficiency - the system chooses the technology that is most efficient at any given time. If outside conditions are too demanding for the heat pump, the traditional boiler system kicks in to meet the shortfall.
  • Reliable all year round - the air source heat pump can be used as an air conditioner in the summer, and then when winter arrives it can act in reverse to keep your home warm.
  • Longer lasting - because they share the responsibility of heating your home, both the air source heat pump and gas boiler won’t need to work so hard, making maintenance simpler.
  • Savings - the heat pump meets the bulk of demand, so there are opportunities for cost and carbon savings. Hybrid heat pumps also have the benefit of being cheaper than a standard electric heat pump because they’re smaller.
  • Earnings through RHI scheme - you could be entitled to earn money through the government’s Renewable Heat Incentive (RHI).

Some barriers :x:

  • High upfront cost - while prices have become more competitive, the total installed cost of a boiler remains significantly lower than a hybrid heat pump. Over time, you should earn the difference back in lower bills and RHI earnings, so it is a longer term investment.
  • Lack of space - while smaller than a standard electric heat pump, you’ll still need a bit of outdoor space. Rural properties are less likely to have space restrictions than urban properties.
  • Not completely renewable - the hybrid system still uses a boiler running on fossil fuels.

Low consumer awareness and reluctance to switch from the familiarity and convenience of gas boilers are major barriers to the uptake of heat pumps. I will be interested to see the outcome of Centrica’s recent partnership with Sanctuary Housing :handshake:. Between April and the end of October, nearly 600 properties across the North, North West, Midlands, East, and South West will have their existing heating systems replaced with low carbon alternatives :earth_africa:.

They’re also urging the government to launch a retrofit fund :moneybag:, which would run from 2022-2024, to transition from gas boilers to hybrid heating systems. Data collected over these 2 years could pave the way :footprints: and establish the role hybrid systems will play in heat decarbonisation in the UK :sunrise: :sunrise_over_mountains: :city_sunrise:.

1 Like

Interesting product hybrids are, thanks for bring light to it Cara. These systems seem like a viable alternative to conventional gas boilers in the future. These should be good for heating the water as well, as modern heat pumps are only really capable of 50C water, and need to heat the water to 60C occasionally for Legionnaires disease prevention with a auxiliary element. Lets just hope there maintained correctly and cleaned often so the boiler isn’t necessary running.

I do see homeowners just using the boiler part though for the quicker heat up times and lower running costs.

Hi @izzyhunt :wave:

They do seem like a great compromise. I believe the maximum temperature of hot water depends on a couple of factors, like the type of refrigerant, size of the coil, etc. but as you’ve mentioned 45-50°C does seem to be the norm and the higher the temperature the less efficient the heat pump will be.

Annual checks and cleaning filters, coils should give heat pumps a lifespan of about 20-30 years which is great. Do you have a heat pump or are you considering it? :thinking:

Cara :bulb: