"The new report is the most recent showing that heat pumps don't just cut greenhouse gas emissions relative to fossil fuel heating, but often save money. …
"The report assumes that a cold-climate heat pump would need a backup heat source, adding an additional cost. Heather McDiarmid, a climate and energy consultant who prepared the reports for the Ontario Clean Air Alliance, questioned whether that would be necessary across Canada."
https://www.cbc.ca/news/science/heat-pump-cost-savings-1.6975426