1. Introduction
Indigenous remote communities relying on microgrids are common among the Arctic regions [
1], especially in Canada, Alaska (United States), Russia, and Greenland (Denmark). Due to the harsh climate, buildings in these regions show high electricity and heat demand, while their remoteness increases energy vulnerability and dependence on fossil fuels. Energy transition in remote Arctic communities is becoming increasingly important, and is at the core of economic, environmental and social considerations for local governments [
2,
3,
4,
5,
6]. The main objectives are reducing building energy demand, decarbonizing heating systems, and developing clean electricity generation. Nunavik is a geographically isolated region in Northern Quebec, home to about 14,000 inhabitants [
7], mostly Inuit and Cree, living in 14 remote communities. These villages are disconnected from the country’s main road and energy networks. They mostly rely on local diesel power plants for electricity generation and most buildings are heated with oil furnaces. The dependence on fossil energy results in significant expenses for power generation. The cost of diesel in Nunavik for the 2023–2024 season was CAD 2.12/L before subsidy, substantially higher than the Quebec average of CAD 1.61/L [
8]. In 2024, Makivvik Corporation announced a direct subsidy to stabilize diesel cost at CAD 1.84/L [
9].
Renewable energy technologies, such as wind, solar, and geothermal, offer promising solutions for sustainable power and heat generation. Transitioning to these alternative sources could allow communities to reduce their carbon footprint, lower energy cost, and enhance energy security and resilience. Geothermal systems in particular hold significant potential for heating buildings in Arctic and subarctic regions, presenting advantages like utilization of an on-site resource for energy, a high-capacity factor, long lifetime, low operational cost, and load flexibility [
10]. However, due to high capital cost, very few projects and installations are running, and little feedback has been provided. Shallow geothermal systems have been the subject to limited field investigation in the high north. In Fairbanks (Alaska) [
11], a horizontal ground loop system, digging down to 2.75 m to install the pipes, was connected to a 465 m
2 building in 2013. Designed for a 17.6 kW heating load, the system demonstrated interesting performance, generating 20,000 to 30,000 kWh of annual heat and avoiding 2650 L of fuel oil annually. Over the first 8-year operational period, the system maintained a COP averaging 3.0 [
12]. The maintenance cost amounts to USD 300 every other year and the geothermal system allowed to stabilize electricity consumption cost to USD 0.24/kWh. A review by Garber-Slaght and Stevens [
13] examined 13 GSHP installations in Fairbanks, including horizontal loops and vertical wells (41 to 76 m), with capacities between 14 and 35 kW. These systems supplied diverse building typologies, covering residential dwellings from 93 to 465 m
2 surface area, multi-unit condominiums, offices, and educational facility make-up air system. While the study generated useful guidelines for decision-making, the authors emphasized the need for long-term performance data for future system design implementation.
Research over the past decades has demonstrated the viability of shallow and deep geothermal potential in Canadian remote northern communities [
14,
15,
16]. In Nunavik, where the ground temperature is near the freezing point of water throughout the year, vertical closed loop systems that circulate antifreeze mixtures are the most effective ground heat exchanger (GHE).
Several studies have assessed the feasibility and benefits of geothermal and hybrid systems in Nunavik. Belzile et al. [
17] simulated an absorption ground-coupled heat pump (GCHP) with a horizontal exchanger in Kangiqsualujjuaq and demonstrated it could reduce heating oil consumption by 40% compared to conventional systems powered by diesel-generated electricity. Giordano and Raymond [
14] showed that a borehole thermal energy system (BTES) assisted with solar thermal panels to heat the drinking water of the Kuujjuaq pumping station could achieve 13% annual oil savings and reduce CO
2 equivalent emissions by 19 tons within three years of operation. In Whapmagoostui-Kuujjuarapik (WK), Maranghi et al. [
18] found that solar-assisted GCHP (SAGCHP) with a compression system reduced fuel consumption by 38%, which could be increased to a 59% reduction with the addition of batteries. Also in WK, Langevin et al. [
19] identified scenarios with compression SAGCHP that could reach 61% greenhouse gas (GHG) savings. Moreno [
20] and Moreno et al. [
21] highlighted hybrid alternatives, like SAGCHP combined with biomass or oil furnace, as promising options that could achieve a reduction of 50% to 99% of GHG emissions. All studies agreed that SAGCHP remains the most suitable option for reducing carbon emissions in Nunavik and enhancing communities’ energy sovereignty. With a diesel power plant efficiency of approximately 30% and a heat pump COP which can be assumed around 3.0 in northern conditions, we obtain a 90% efficiency for the whole system, that can achieve similar performance as conventional oil furnace or boiler. Hence, assistance from renewable energy is mandatory to partly provide clean electricity to the heat pump compressor if we want to reduce GHG emission and have significant environmental gains.
Despite the promising results, renewable energy development in isolated Arctic regions is an economic challenge. For vertical geothermal systems in general, drilling cost can represent about 30 to 50% of the capital cost of a project [
21]. In Nunavik, drilling equipment is already present in certain locations, such as Kuujjuaq, but is specialized in mineral exploration. Diamond drills used for mineral exploration are more compact than usual geothermal rigs, thus easier to transport, but the drilling diameter is narrower and less adapted for GHE. Considering a drilling cost between CAD 50 and 300/m, Gunawan et al. [
15] emphasized that SAGCHP systems still can be economically more attractive than oil furnace heating as all the studied scenarios present a relatively fast payback between 3 and 12 years. Moreno et al. [
21] identified a promising strategy of net metering, obtaining credits for injecting surplus electricity from solar panels into the grid, to reduce cost and make systems even more economically competitive.
Meyer et al. [
4] and Garber-Slaght and Stevens [
13] emphasizes the importance of accurate GSHP sizing, highlighting the need for full data on operational buildings in arctic and subarctic regions. However, a significant literature gap exists regarding northern building performance. Rouleau and Gosselin [
22] monitored ten dwellings, limited to a single building typology (semi-detached), reporting heat demands ranging from 180 to 350 kWh per m
2 of surface area and a daily electricity consumption between 6.21 and 29.20 kWh. One-year monitoring studies of high-performance demonstration house were conducted in Iqaluit (Nunavut, Canada) [
23], Sisimiut (Greenland) [
24], and Kiruna (Sweden) [
25,
26], but these dwellings were mostly unoccupied, necessitating further research that includes the impact of occupant behavior. Furthermore, data on non-residential buildings—such as grocery stores, healthcare facilities, and recreational centers—which are found in most northern communities, remain even scarcer, accounting for the critical gap in current scientific understanding.
The present work focuses on the Kuujjuaq Forum, an important activity center in Kuujjuaq, which is an Inuit community of 2700 inhabitants [
7] located on the 58° parallel in Nunavik. The climate is characterized by harsh winters, with low temperatures, strong winds, and short days. Average annual temperature is −5.4 °C [
27], with 8523 heating degree days below 18 (HDD18) [
28]. Recent geothermal tests in Kuujjuaq revealed promising thermal properties, with an average ground temperature of 1.8 °C between 15 and 145 m depth and thermal conductivity of 2.67 ± 0.25 W m
−1K
−1 [
29,
30]. In Nunavik, the annual average heating demand for a typical dwelling is 310 kWh/m
2 [
1], compared to 145 kWh/m
2 in southern Quebec [
31]. The Forum is also equipped with a monitored PV system, reducing reliance on the local diesel-powered microgrid.
In this context and in collaboration with the building’s owner, Kuujjuamiut Society, this project was initiated to evaluate the potential of SAGCHP system for space heating in the Kuujjuaq Forum. This study gathers field data on the Kuujjuaq Forum’s heating and electrical demand, alongside its PV panels’ electricity generation, to assess the feasibility of integrating a SAGCHP system. The objective of the study is to propose sustainable energy solutions for the building, leveraging both geothermal and solar energy to reduce reliance on diesel. Oil bills and technical documents were analyzed to assess the energy consumption of this operating building and develop an energy model. The results were used to size and model a GCHP system to meet part of the heat demand. The potential of a new, larger PV system to assist heat pumps was evaluated. Finally, a quick environmental and economic analysis was carried out. By presenting field data and addressing the technical, environmental, and economic challenges of sustainable energy transition in Nunavik, the present work contributes to fill the data gap of energy consumption for non-residential buildings and solar PV electricity generation in Arctic to subarctic regions. We believe this represents a significant scientific contribution as there is little information available in the literature about operating buildings in such climate. Results are discussed in the energy transition context to provide guidelines for other remote communities living in similar climatic conditions and facing similar challenges to decrease their fossil fuel consumption.
5. Discussion
The implementation of SAGCHP system in northern remote communities present both promising opportunities and significant challenges that warrant careful consideration. This discussion examines the key findings of our study while considering limitations and future research directions.
Regarding the simulation methodology, some limitations should be considered when interpreting the results. The use of Meteonorm weather data from TRNSYS 18 documentation provides a standardized basis for analysis but may not fully capture the actual 2020–2024 climate conditions in Kuujjuaq. Also, the Arctic region is highly sensitive to climate change and Nunavik is expected to experience significant changes in weather conditions in the coming years [
27,
53,
54]. Future studies would benefit from using real-year weather data or climate prediction models to enhance the reliability of the building’s simulation results. The model’s accuracy can also be influenced by uncertainties in building operation parameters, including occupation fluctuations, occupants’ behavior, manual settings, ventilation flows, real heat consumption patterns, and other values that can deviate from theoretical assumptions. This gap between model’s predictions and building’s real energy use is known as energy gap and is the subject of numerous research projects aimed at reducing it [
55,
56,
57].
Due to Nunavik’s extreme climate conditions, the severe imbalance between ground heat extraction and injection periods is identified as a substantial challenge in implementing a GCHP system [
18,
19]. This imbalance affects the long-term stability of ground temperatures and system performance. Seasonal thermal storage strategies emerge as a potential solution to address this thermal imbalance, as well as the characteristic mismatch between energy demand and solar energy generation in northern regions. One recommended solution for maintaining a balanced soil temperature could be to use the heat from the ambient air during the hottest periods of summer to inject it into the soil. That aspect has not been simulated in this study as we choose to analyze the viability of the system under the most demanding conditions, without heat reinjection. A robust GHE system was designed and assessed to provide operational temperatures above or close to the minimum allowed for conventional heat pumps throughout the system’s lifetime. For the solar PV system, the module’s power degradation over its lifetime and its impact on annual yield has not been considered in our 25-year analysis. A large analytical review [
58] found that PV panels lose about 0.5% of power capacity per year of operation. Thus, in a 25-year analysis, PV modules’ performance would go down to about 88.5% of the original power, with an average of 94% performance over the 25 years period. This consideration could be added in further studies.
Previous research confirmed that ventilation heating and in-floor heat delivery are the most relevant way to use geothermal energy, as they can function with low temperatures around 30–50 °C, unlike baseboard heat emitters that requires fluid temperatures of 60–80 °C [
10,
13].
The management of excess solar energy generation presents other options:
The most interesting solution, therefore, is to adopt a community-wide vision by exporting excess power back to the local grid, creating mutual beneficial arrangements between building owners, local grid operators and community users. While biomass represents one of the most attractive techno-economic alternatives to diesel [
59], communities remain dependent on imports, unlike geothermal energy which increases energy independence. Moreno [
20] showed that an energy mix supply, like a combination of geothermal, photovoltaic, and biomass systems, is the most interesting option to ensure reliability and carbon emission reduction. During 2024, in Fairbanks, the Alaska campus was running one third on their horizontal ground loop system, one third on a biomass boiler, and the final third on a diesel boiler [
11]. Other studies demonstrate that the rentability of a GSHP system significantly varies according to fuel oil prices [
12,
60]: when oil costs are high, GSHP systems allow for more savings compared to a conventional oil boiler. Hence, an optimal solution can be found using thoughtful energy mix to significantly reduce GHG emissions: solar and geothermal energy to benefit from local renewable energy and increase sovereignty, and biomass energy to support and fill the gaps left by the first two. This study aims to fill the gap in knowledge regarding arctic and subarctic building’s energy consumption, solar PV system electricity generation, and shallow geothermal heat pump systems. Deep geothermal systems were not discussed here but are also promising solutions for sustainable energy in the North, and several pilot projects are underway in Canada [
61,
62].
Over the past decades, melting sea ice in the Canadian Arctic and development of northern communities has led to an increase of fuel consumption and shipping, and the risk of oil spills has multiplied. Whether they occur offshore or on land, these oil spills have catastrophic consequences for ecosystems, societies and the economy, and they are recognized as serious issues by governments of USA, Canada, and Russia [
63,
64,
65,
66]. Reducing oil consumption in communities by developing local and renewable energy sources is the first step to tackle this problem.
The results of this study can be applied to other regions presenting similar climate conditions. Data on building’s heat loads are useful for areas presenting similar temperature normal (−5.4 °C [
27]), HDD18 (8523 [
28]); data on PV panels electricity generation can be applied for communities located around the same latitudes (58°); while results on GCHP design would be mostly appropriate in sporadic and discontinuous permafrost areas like Kuujjuaq [
67]. This is the case of other subarctic regions found in Canada and within the Yukon and Northwest Territories. Conclusions on GCHP performance might not be relevant for regions facing more severe arctic climate and continuous permafrost, like in Nunavut (Canada), for example. The type of heat and power distribution network is also important. Results and conclusions of this study will be useful for remote communities that rely on integrated and local energy system, like in Canada, Alaska, Greenland, and part of Russia. Scandinavian countries, Iceland, and some areas in Russia are typically connected to a national grid, hence, the strategies for decarbonization might be different.
Eventually, as mentioned earlier, the economic viability of SAGCHP system in remote northern communities must be evaluated within the context of rising energy costs, carbon pricing policy, environmental benefits, social benefits of local energy generation, and increased energy independence.
6. Conclusions
This study addresses an important knowledge gap regarding building energy consumption and renewable energy integration in Nunavik, which can be applicable to other remote arctic to subarctic regions. The article focuses on analyzing the heating demand of the Kuujjuaq’s Forum (Nunavik, Québec). A building model was developed to investigate and quantify the heating demand profiles, with a particular emphasis on ventilation requirements. These profiles were used as input values to size a ground-source heat pump system. Then, a dynamic model of the vertical geothermal heat exchanger was built in TRNSYS 18 and coupled with heat pumps to supply air preheating loads. Eventually, heat pump energy demand was compared to the energy generation of additional PV panels that would cover the entire roof of the building. The findings demonstrate the potential of SAGCHP systems for the Kuujjuaq Forum, with several key outcomes:
The Forum’s real heating consumption averages 573,180 kWh/year, including radiators, ventilation and domestic hot water. The building model reached similar results with an annual heat demand of 574,290 kWh, corresponding to an energy use of about 143 kWh/m2. Ventilation heating accounts for 381,230 kWh of this load, with preheating (268,200 kWh) and terminal heating (113,030 kWh).
Analysis confirms that GCHP could be a viable option to manage a significant portion of the ventilation heating load, particularly the air preheating which accounts for 70% of the total air heating demand and 47% of the total heat demand (ventilation, radiators and DHW). The system design indicates that a minimum of 60 boreholes with a borehole depth between 160 and 200 m, corresponding to 9600 to 12,000 linear meters of heat exchangers, would be required to ensure reliable operation within the heat pump’s operational parameters, considering the average ground temperature of 1.8 °C.
The proposed GCHP system can generate the 268,200 kWh of annual heating to meet the air preheating demand, avoiding 31,128 L of fuel annually. The system demonstrates an average COP of 3.44 and shows a maximum capacity of 88.30 kW to meet the requirements. Of the 77,980 annual kilowatt-hours of electricity required by the heat pump, approximately 23,773 kWh could be supplied by an additional PV system of around 1380 m2 and 275 kWp. This system’s annual penetration averages 37%. Seasonal analysis reveals average solar energy coverage of 22% during winter and a peak average penetration reaching 53% during early spring.
Despite an important investment cost, the economic and environmental analysis suggests that the SAGCHP could enable CAD 19,940 and 38 tCO2eq savings per year at building scale. The yearly benefits go up to 177 tCO2eq and CAD 164,960 savings if the analysis is extended to the community scale, taking into account solar energy exports from the PV system to the grid.
Assumptions about the proposed additional panels on the total surface of the roof were made. However, the building may have structural constraints that prevent the installation of more panels. If this is the case, another surface should be considered to increase the number of solar panels and therefore the system’s capacity to power GCHP installation.
To conclude, this research provides unprecedented data and contributes to the understanding of heating and electricity consumption patterns in subarctic non-residential buildings, while also providing valuable insight on integrated PV systems performance. The results indicate that SAGCHP system can be technically viable for large-scale applications in Nunavik, like Kuujjuaq Forum, but still question the economic viability. While the economic challenges of implementing SAGCHP systems in Northern Quebec and other subarctic regions are significant, the combination of several factors such as potential government incentives, protection against rising carbon prices, and enhanced energy security can make it a strategic investment for long-term sustainability and operational stability. Such a project still offers meaningful reductions in both GHG emissions, operational costs, and oil dependence. A forthcoming pilot project, involving the installation of a small-scale GHE connected to the Forum, will provide crucial empirical data to validate the present findings and inform decisions for a full-scale system implementation.