Integration of deep geothermal energy in Canada's energy portfolio

Lead Proponent: Institut de recherche d’Hydro-Québec (IREQ)
Location: Varennes, QC
ecoEII Contribution:  $ 800,000
Project Total:  $  3,343,000

Background

The development of an enhanced geothermal system (EGS) allows for the possibility of developing the geothermal sector by creating reservoirs in environments that do not naturally have all of the elements required for conventional hydrothermal geothermal energy (heat, fluid, and a permeable geological environment) and of leveraging the enormous amount of thermal energy stored in the subsurface for electricity production. In the U.S., its potential is estimated at 100,000 MW by 2050. A majority of Canada’s land contains hot rocks located several thousand metres deep, and deep geothermal energy stimulated by hydraulic fracturing has the potential to become an important matrix of energy supply. Although current technology would provide access to geothermal energy potential, the exploitation of the resource has not yet been demonstrated to be profitable and research is necessary in order to identify the most suitable sites, to create and manage reservoirs, and to optimize the conversion of heat into electricity. In the past, special attention was paid to the potential of Western Canada.

Recognizing the need to develop knowledge and expertise before embarking on an experimental project in deep geothermal energy in Quebec and Eastern Canada, Hydro-Québec proposed the project “Integration of deep geothermal energy in Canada's energy portfolio” for funding through the ecoENERGY Innovation Initiative. The Initiative awarded the project $800,000. Hydro-Québec, through its Institut de recherche d’Hydro-Québec (IREQ), was the lead proponent of the project.

Results

The electricity production potential of deep geothermal energy was assessed for Quebec and Eastern Canada. The St. Lawrence Lowlands (SLL) and Appalachian Mountains were a particular focus. A 3D model was built for the SLL basin. Maps showing the heat flow and temperature at different depths were produced using geophysical data and temperature measurements from oil, gas, and mine drilling. Work to analyze geophysical parameters (radiation sources, density, magnetic susceptibility, etc.) was done to refine the models, with the aim of improving the exploration techniques used to locate resources.

Simulations were carried out for the geothermal power plants themselves (cycle and fluid optimization) and for geothermal systems as a whole. These simulations made it possible to identify the main factors affecting electricity production, to better predict the potential impact of technological development, and to perform an opportunity analysis based on the main cost components of such systems.  The results indicate that a commercial project is not viable in the short or medium term in Quebec, especially if the subsurface resource is at a temperature below 150°C.

A comparative analysis of nine sites in different areas of Quebec was performed based on criteria such as the quality of the resource, and economic as well as social factors. The sites identified are generally not appropriate for a large-scale pilot project in the short term, primarily due to the required depths, uncertainty over the temperature, and the risks associated with deep reservoirs.  However, a significant reduction in deep drilling costs and the development of expertise in the creation of geothermal reservoirs could potentially pave the way for growth in this sector. Different avenues for future work were set out in the project synthesis report.

Benefits to Canada

This project could eventually bring about the development of a new industrial sector. The enhanced geothermal system could provide an easily scalable baseload supply similar to hydro generation and, therefore, complement other types of renewable energy.  

Next Steps

A large-scale pilot project is hardly conceivable at present given the costs associated with deep drilling.