Alberta would cut its carbon footprint by a mere five per cent if it blended hydrogen with its natural gas, a new study suggests.
University of Alberta mechanical engineer Prof. Amit Kumar and his team published a study last month in Renewable and Sustainable Energy Reviews on the greenhouse gas reduction potential of blending natural gas with hydrogen in Alberta.
Hydrogen does not produce greenhouse gas emissions when burned and has been pitched as a way to reduce emissions from heating by displacing natural gas. ATCO is now seeing if it can heat Fort Saskatchewan homes using a five per cent hydrogen/natural gas blend.
Albertans can replace 15 to 20 per cent of the natural gas in their pipes and furnaces with hydrogen using current technology, said Kumar, who advised the provincial government on its Hydrogen Roadmap. (We’d need different pipes and furnaces to run off pure hydrogen.) His team used a complex economic model to see if it is cost effective for Alberta to reduce its carbon footprint by switching to a 15 per cent natural gas/hydrogen (“hythane”) blend.
High cost, low reward?
The team found that a 15 per cent hythane blend would cut at most five per cent off of Alberta’s carbon footprint by 2050 (assuming it was not used in the power sector) and would result in higher average energy prices unless the carbon price rose to $300 to $400 a tonne — about five to six times what it is now.
In an email, Kumar said the low emission reductions were a combination of the quantity of gas replaced with hydrogen in hythane (just 15 per cent by volume) and the added emissions caused by hydrogen production (some of which could not be carbon-captured). The higher costs were because of the price difference between natural gas (about $4/GJ) and hydrogen (about $13/GJ) and the capital investment needed to produce and transmit hydrogen.
There are also practical problems with hydrogen, the team found. Since hydrogen carries less energy per volume than natural gas, you actually have to burn more hythane in total to get the same amount of power, Kumar said — replacing 15 per cent of the gas ends up reducing emissions by just five per cent. The price gap between natural gas and hydrogen could also drive up energy bills, which could make hythane less acceptable to consumers.
The team found governments should invest in energy efficiency, green electricity, and adding carbon capture to hydrogen plants before hythane, as those measures would produce bigger emission cuts for less money.
While some hard-to-decarbonize industries could benefit from hydrogen, blending it with natural gas for home heating might not be the best way to use it, said Betsy Agar, manager of the Pembina Institute’s buildings program.
“This seems like a lot of investment for a nominal gain,” Agar said, when asked to comment on hythane.
Agar said Alberta should focus on greening its electricity grid and making homes more energy efficient if it wants to reduce greenhouse gas emissions from heating, and should reserve hydrogen for specific industrial purposes.
Kumar said Alberta could use hythane to gain experience with hydrogen production and use without a lot of new investment. Alberta has lots of natural gas and carbon-capture infrastructure, and hydrogen could help us create jobs and draw investment.
“For us to continue to grow as an energy economy and continue to export our resources which will be in demand over the decades to come, hydrogen provides a realistic option,” Kumar said.
The study is available at bit.ly/3K7bgbK.
