New research by a University of Alberta engineer suggests using hydrogen to heat Alberta homes would shave a mere two per cent off the province’s carbon footprint and make home heating more expensive.
U of A research engineer and PhD student Matthew Davis spoke at the Canadian Hydrogen Convention at the Edmonton Convention Centre April 26 on reducing greenhouse-gas emissions by blending hydrogen with natural gas.
About 41 per cent of Canada’s greenhouse-gas emissions come from natural gas, reports Our World in Data. Much of that gas is burned in homes for heating. This fall, Atco plans to swap about five per cent of the natural gas used to heat some homes in Fort Saskatchewan with hydrogen (which produces only water when burned) to see if it can reduce greenhouse-gas emissions.
We can currently replace up to 15 to 20 per cent of natural gas in our homes with hydrogen using current technology, said Davis, speaking in advance of the conference — we need different appliances and furnaces beyond that point, and replacing those items is expensive.
Davis created an economic model of Alberta’s energy systems to see how hydrogen for home heating stacked up against other ways to reduce the province’s carbon footprint. The model studied 500 long-term scenarios and looked at every step of the hydrogen production and consumption process.
He found that in the best-case scenario, Alberta could cancel up to two per cent of its carbon emissions if it replaced 15 per cent of the natural gas used for home heating with hydrogen — not a lot, in other words.
“If we’re looking to find ways to reduce greenhouse gases using hydrogen, burning it with natural gas is not going to provide much of an impact,” he said.
It’s a problem of energy density, Davis explained. Hydrogen has less energy in it per molecule than natural gas, so if you replace 15 per cent of your gas with hydrogen, you reduce the amount of energy your furnace gets from gas by just five per cent. You have to run your furnace more as a result, which cuts into your carbon reductions.
Davis said this hydrogen swap would increase consumer gas costs unless Alberta had a carbon tax of more than $300 a tonne — far above the $170 per tonne currently envisioned by the federal government. His analysis found Alberta could reap bigger carbon cuts for much less money if it instead added carbon capture systems to conventional hydrogen production.
Davis said using hydrogen to displace gas in homes isn’t an efficient way to reduce emissions, but could be worthwhile if your goal was to create demand for hydrogen to foster a hydrogen economy. Hydrogen could also be valuable for storage of solar and wind power.
Hydrogen is still an emerging field of study, and it definitely has a role in a net-zero energy system, Davis said.
“The question is how are we going to use [hydrogen] in the most cost-effective way?”
A summary of Davis’s talk can be found at hydrogenexpo.com under the conference/technical courses menu.
