GIS-based potential assessment and scenario analysis for integrating geothermal heat pumps technologies in urban energy systems

Abstract

Cities have a significant impact on global energy consumption and carbon dioxide emissions (CO2), with buildings being the main electricity consumers. However, efforts to reduce the carbon footprint of cities can be challenged by unforeseen events like the Covid-19 pandemic and international conflicts. These events, while increasing energy prices, also provide an opportunity to promote renewable energy. To decarbonize urban energy systems (UES) and replace conventional fossil fuel-based heating, ground source heat pumps (GSHP) and aerothermal heat pumps (AHP), are compared. AHP are cheaper and easier to install but less efficient, potentially straining the electricity grid. Incorporating shallow geothermal energy (SGE) into UES can reduce electrical grid requirements to couple heating demand compared to using AHP. This study develops a heat supply model using Geographic Information System (GIS) and open-source data to assess the SGEs feasibility. The model analyzes different integration scenarios. Three datasets were used to model the urban energy systems in Oldenburg: infrastructure, energy potential and geothermal system locations. The study employed the FlexiGIS tool to set the city infrastructure and estimate electricity demand. The scenarios considered the power and energy demand of aerothermal and geothermal heat pumps, as well as a distributed system using geothermal potential. The study concludes that GSHP using borehole heat exchangers (BHE) is the most suitable SGE for urban implementation due to their efficiency, space requirements, and reduced pressure on power distribution networks compared to AHP. Likewise, SGE systems can provide a cost-effective and environmentally friendly alternative for space heating and hot water.