What about ground-sourced heat pumps?
An excellent overview of geothermal direct-use in Canada was presented at the 2015 World Geothermal Congress and has been published by Raymond et al (2015), and includes a summary of ground-sourced heat pump deployment in Canada.
Ground-sourced heat pumps (GSHPs) is also known as earth energy systems (EES), GeoExchange, and ground-coupled earth systems. Much more information is available at Canadian GeoExchange Coalition.
Due to their relatively mature industry in Canada, GSHPs were not covered by our project. Having said that, the deployment of GSHPs is important in reducing carbon emissions and for electricity conservation, particularly when used in higher density district energy systems.
The graphs below show the uptake of GSHPs in Canada. 90% of GSHPs replace heating systems by propane, fuel oil and electricity.
Distribution of heat pump systems certified by Canadian GeoExchange Coalition (CGC) (Raymond et al., 2015)