This article was written by Richard Carlson, director of energy at Pollution Probe, Canada’s oldest environmental NGO, and was published in the Toronto Star on May 14, 2023.

In Ontario’s cold winters we burn a lot of natural gas to stay warm. Heating accounts for over 80 per cent of the energy we use in our homes, and over 75 per cent of Ontarians use natural gas for that heating. In the GHTA, emissions from heating buildings with natural gas is the largest source of greenhouse gas emissions, even higher than from transportation.

While natural gas has proven to be cost-effective, reliable and a flexible fuel, will we always be heating with natural gas? We are in a climate emergency and we have to stop burning fossil fuels so we need to prepare for replacing natural gas.

Electrification is the most common low-carbon solution promoted, especially as we are working to decarbonize our electricity supply. Rather than heating with inefficient electric baseboard heaters, it is heat pumps, essentially air conditioners that can both heat and cool, that offer the greatest promise. As heat pumps move heat and not create heat, that can be incredibly efficient, producing more heat than the energy put in.

But heat pumps struggle at really low temperatures. While less than 10 per cent of Canadian total heat demand would be cold enough that heat pumps would struggle, on those really cold days heating is still crucial. Using electric baseboards as a backup is one idea. But as everyone would be needing these backups at the same time, there would likely lead to much higher costs as the electricity grid would need to be expanded to meet these peak heating days in the winter.

As an example, Quebec, which relies heavily on electric baseboards for heating, has almost double the electricity demand in the winter as Ontario has during our highest period of electricity demand when everyone has their air conditioning blasting.

Even if Quebec moves to heat pumps, this large winter demand would remain as the baseboard heaters would be going full out as a backup.

Studies have shown that for the electricity grid to meet heating needs on those really cold days in Ontario, and in comparable areas, it would have to almost double in size. And this is not just with power plants, but with all the wires transporting the electricity to every home.

Thus what we would see would be a lower average use of energy, with large spikes in electricity demand by everyone in a short period. It would be like building massive highways all over Toronto just to deal with the rush of cottagers north in the summer.

But given that we need to reduce our emissions, we have to do something. In a paper Pollution Probe published, we argued that we need to look beyond electrification. District heating, which is already used in Toronto, is one.

For homes, hybrid heating — systems that have both a heat pump and a natural gas furnace — could be transitional tools as we develop our electricity system and improve the energy efficiency of our homes. The City of London is testing hybrid heating, and in Quebec, the electric and gas utilities, Hydro Québec and Énergir, are working together on hybrid systems. Hybrid systems could even be made low carbon if they used renewable natural gas or other low-carbon gases.

Decarbonizing heating is likely to be extremely difficult, given our current reliance on natural gas, extremely cold winter temperatures and the need to maintain the accessibility, affordability and reliability of heating services.

Given the need to move, we cannot afford to wait and need to consider all options, not just electrification, while planning — and preparing — for a net zero future.