Geothermal Energy

Geothermal Energy

The geothermal energy distribution of the Earth: deep sources -core and mantle; shallow source - crust. Credit: modified from Grasby geothermal PowerPoint presentation, November 23, 2018.

Description

Geothermal energy is thermal energy generated and stored in the earth. It is generated by the radioactive decay of Uranium, Thorium, and Potassium in the crust and flows to the earth’s surface. A smaller amount of heat energy also flows to the earth’s surface by the cooling of the mantle.  It is a renewable, clean energy resource that can be used for power generation, district heating (heat buildings), and natural bath spas. The Northwest Territories may have geothermal energy potential associated with hot brines located in laterally contiguous, porous, and permeable reservoirs in sedimentary basins.  There is also district heating potential associated with deep warm water present at depth in local mines such as the Con Mine near Yellowknife.

Depth in kilometres to 120 °C. Credit: modified from Majorowicz and Grasby, 2013.

Location

Temperature data from petroleum wells have been used to estimate geothermal temperatures at depth. The southwestern portion of the Northwest Territories appears to have the highest geothermal temperatures at the shallowest depths (light and dark yellow regions of the map within the red oval outline). On this basis, southwestern NWT may have the most favourable attributes for geothermal energy direct heating and energy projects associated with sedimentary basin brines. Some of the communities that are located within the high graded region include Fort Liard, Fort Simpson, Jean Marie River, Fort Providence and Hay River.

The Con Mine, located in hard subsurface bedrock in the Yellowknife area, has heated subsurface groundwater present at depth and may be a good candidate for a local district heating project.

Justification

In northern Canada, high greenhouse gas (GHG) emissions are associated with the use of diesel to generate electricity in remote communities. Recent federal, provincial and territorial government mandates to reduce GHG emissions has resulted in a renewed interest in the development of alternative renewable energy resources, including geothermal energy.

The Energy Division of NWT’s Department of Infrastructure is currently working to diversify its energy mix by including the increased development of renewable and alternative energy resources. Successful implementation of this strategy will result in the reduction of GHG produced during energy production.  The NWT Geological Survey (NTGS) Strategic Plan 2017-2022 also expanded the strategy to assess NWT energy resources by including geothermal energy as one of the energy resources for further technical assessment. The inclusion of this form of energy as an NTGS research focus area will result in the delivery of the geoscience required to understand this resource and its potential contribution to NWT energy needs.

Benefits of the successful development and implementation of geothermal energy production and district heating projects may include:

  • Provide baseload renewable, low GHG energy compliant with the current government mandates.
  • Lower cost of living and potentially stimulate new and diversified economic development.
  • Provide geoscience to support the development of geothermal legislation that is tailored to NWT opportunity and needs.
Block model of a sedimentary basin geothermal system. Credit: ERCB/AGS Open File Report 2009-11.

Approach

NTGS will work with the Department of Infrastructure – Energy Division to identify priority research projects, deliverables and timelines.

Fort Liard, Northwest Territories. Credit: Timkal.

Schedule

NTGS and the Department of Infrastructure – Energy Division will meet before the end of Fiscal 2018-19 to identify priority research projects, deliverables and timelines.

Partners and Support

  • GNWT - Department of Industry, Tourism and Investment (ITI) - NTGS Division
  • GNWT - Department of Infrastructure-Energy Division
  • Natural Resources Canada (NRCan) – Geological Survey of Canada
  • NRCan- CanmetEnergy
  • University Research Collaborators – to be determined
  • Industry Collaborators – to be determined
  • City of Yellowknife
An expert panel at the 2018 Geothermal Workshop in Yellowknife. From right to left: Dr. Maurice Dusseault, Dr. Jasmin Raymond, Dr. Catherine Hickson, Dr. Grant Ferguson, and Dr. Steven Grasby. Credit: Terlaky.

Keywords

energy resources, southwestern NWT, power generation, district heating, Con Mine, energy heating projects, GHG, greenhouse gas emissions, alternative energy, renewable resource development