Electric heat pumps out-perform fossil fuel and baseboard electric heating at winter temperatures as low as -10°C, and according to some data as low as -30°C, concludes a research commentary published this week in the journal Joule.
The results show that “heat pumps are key to decarbonizing Canadian buildings,” said lead author Duncan Gibb, senior advisor at the UK-based Regulatory Assistance Project (RAP). “This research features data from Canada and shows that heat pumps can perform more than twice as efficiently as an electric heater or gas furnace—even on the coldest day of the year.”
While “some commentators and the media have repeatedly suggested that heat pumps cannot deliver useful efficiencies at lower temperatures,” real-world performance data shows that air-source heat pumps are the more efficient option in countries where temperatures rarely fall below -10°C, the research team writes.
In extreme cold, heat pump efficiency declines, and homes may need back-up heating, the paper adds. But even then, cold-climate heat pumps “can still provide significant energy system efficiency benefits on an instantaneous and annual basis compared with alternatives.”
In recent years, heat pump deployments have increased in many countries, the commentary states. “Intriguingly, in Europe their use is most concentrated in countries with colder climates,” the researchers state, with Norway, Sweden, and Estonia installing just over 60, about 45, and 35 units per hundred households, respectively. While there’s no efficiency data on those devices, “the large share of household installations suggests that heat pumps can effectively provide heating in colder climates.”
Field tests of the devices’ performance in extreme cold demonstrated solid performance at temperatures of -12°C in Minnesota, -20 to -30°C in Finland, -and -25 to -35°C in Alaska.
Because heat pumps operate so efficiently, delivering at least 1.5 and an average of three or four units of heat for every unit of electricity they consume, the devices “could be economic winners in Canada if the price of natural gas and heating oil rises,” Gibb told The Energy Mix in an email. “Whether this rise is linked to a supply crunch or the carbon tax, electricity would only need to be less than 2x more expensive than the fossil alternatives. That’s certainly the case in some provinces like Quebec, British Columbia, and maybe Ontario.”
Earlier this year, Clean Energy Canada reported that wind and solar farms with battery backup were both cheaper to build than natural gas power plants in Ontario and Alberta, and the price of the renewable options was expected to fall another 40% by 2035.
