Uncertainty and Risk Evaluation of Deep Geothermal Energy Source for Heat Production and Electricity Generation in Remote Northern Regions

Abstract

The Canadian off-grid communities heavily rely on fossil fuels. This unsustainable energetic framework needs to change, and deep geothermal energy can play an important role. However, limited data availability is one of the challenges to face when evaluating such resources in remote areas. Thus, a first-order assessment of the geothermal energy source is, therefore, needed to trigger interest for further development in northern communities. This is the scope of the present work. Shallow subsurface data and outcrop samples treated as subsurface analogs were used to infer the deep geothermal potential beneath the community of Kuujjuaq (Nunavik, Canada). 2D heat conduction models with time-varying upper boundary condition reproducing climate events were used to simulate the subsurface temperature distribution. The available thermal energy was inferred with the volume method. Monte Carlo-based sensitivity analyses were carried out to determine the main geological and technical uncertainties on the deep geothermal potential and risk analysis to forecast future energy production. The results obtained, although speculative, suggest that the old Canadian Shield beneath Kuujjuaq host potential to fulfill the community’s annual average heating demand of 37 GWh. Hence, deep geothermal energy can be a promising solution to support the energy transition of remote northern communities.

Are Engineered Geothermal Energy Systems a Viable Solution for Arctic Off-Grid Communities? A Techno-Economic Study

“…Moreover, Miranda et al [28,48] present the results of thermal conductivity, volumetric heat capacity, radiogenic heat production, density, porosity and primary rock permeability evaluated for the samples collected. The thermal conductivity and volumetric heat capacity were analyzed considering the samples at dry and water saturated states and for temperatures ranging between 20 and 160 °C [28].…”

“…The lithologies outcropping in Kuujjuaq were sampled and a detailed description of texture, fabric, main mineral phases and major and trace geochemical elements is given in Miranda et al [48]. Moreover, Miranda et al [28,48] present the results of thermal conductivity, volumetric heat capacity, radiogenic heat production, density, porosity and primary rock permeability evaluated for the samples collected. The thermal conductivity and volumetric heat capacity were analyzed considering the samples at dry and water saturated states and for temperatures ranging between 20 and 160 • C [28].…”

“…Moreover, Miranda et al [28,48] present the results of thermal conductivity, volumetric heat capacity, radiogenic heat production, density, porosity and primary rock permeability evaluated for the samples collected. The thermal conductivity and volumetric heat capacity were analyzed considering the samples at dry and water saturated states and for temperatures ranging between 20 and 160 • C [28]. Furthermore, a temperature profile was measured in a groundwater monitoring well located nearby the community and the terrestrial heat flux evaluated following a 1D inverse heat conduction approach, as explained in Miranda et al [49] (Figure 4a).…”

“…Among these options, deep geothermal energy sources can play a key role to provide baseload power and/or heat to the off-grid settlements (e.g., [18][19][20][21][22][23][24][25][26][27]). In fact, a first-order community-scale geothermal assessment undertaken in Kuujjuaq (Nunavik, Canada) suggested that the deep geothermal energy source can fulfil the community's annual average heating demand of 37 GWh [28]. This community is settled on the Canadian Shield, a physiographic region that has been considered a target for geothermal exploration through engineered/enhanced geothermal systems [25,29].…”

3DHIP-Calculator—A New Tool to Stochastically Assess Deep Geothermal Potential Using the Heat-In-Place Method from Voxel-Based 3D Geological Models

“…The volumetric "Heat-In-Place" (HIP) method, implemented by the United States Geological Survey (USGS) [5], together with its subsequent revisions [6][7][8][9][10], is still the most widely used evaluation technique for the estimation of the available stored heat and the recoverable heat fraction (Hrec) of deep geothermal reservoirs [11][12][13][14][15][16]. This method considers the volume of the reservoir (surface and thickness), the petrophysical properties (e.g., rock type, porosity, specific heat capacity, etc.…”