The future of geothermal renewable energy is being spearheaded by University of Alberta researchers.
The university is developing new energy options thanks to $75 million in funding for the Future Energy Systems initiative. As part of the program, Jonathan Banks, a geoscientist and research associate at the U of A, is exploring opportunities to produce geothermal energy in Alberta. Originally from Boston, Banks has been involved with the geosciences since 2005 including four years of working with the geothermal industry in Germany.
“Typically, when people think of geothermal energy they think of Iceland or Hawaii where there is a volcano or tectonically active areas,” said Banks. “We don’t have those here in Alberta.”
This type of renewable energy is produced by relying on the natural geothermal gradient of the Earth. The gradient shows that the subsurface temperature increases with depth. In a setting like Alberta, this means that the Earth warms 30 degrees Celsius per kilometre. Exploiting this principle, geothermal scientists can drill wells to get at subsurface water which is found in hot sedimentary aquifers. The water is brought to the surface and used to power a turbine to create electricity.
“To get to water that is hot enough to boil on its own we would need to drill three and a half to four kilometers,” Banks said. “We already do this in Alberta.”
Banks believes Alberta is at a unique advantage when it comes developing a geothermal energy industry because there are already so many wells created for oil extraction. From these wells, hot water is produced as a by-product.
“Many of the oil plant wells across Alberta are producing 90 per cent hot water and 10 per cent oil,” Banks said. “Those wells are oriented to minimize the flow of water and maximize the flow of hydrocarbons, like oil and gas. We want this the other way around.”
This project aims to find an economical way to either repurpose existing wells for geothermal energy production or drill new wells.
“All the risk is up front with geoscience,” said Banks. “It is all in exploration, research, and development. If we can get over that first hurdle the power plants will work.”
Geothermal energy has small maintenance costs and very little market volatility associated with it. Coal or natural gas plants are tied to trading commodity prices that can change dramatically at a moment’s notice, but according to Banks, the production of geothermal energy would not need to rely upon fluctuating market prices. Many geothermal plants have a small land footprint, some in Germany are only half a football field in size.
“There are some environmental impacts,” said Banks. “Carbon emissions are involved in the drilling and there can be some emissions in the operating of the plant.”
Despite these factors environmental factors, Banks remains optimistic about the future of geothermal energy and its financial competitiveness in Alberta.
“Overall, as far as renewable technologies go, geothermal energy has the lowest footprint of any of the major renewables. It is constantly competing with (natural) gas in today’s economy,” he said.
Read about U of A scientists researching how to convert air pollutants into fuels as part of the Future Energy Systems initiative here.