A novel modelling approach of ground source heat pump application for district heating and cooling, developed for a case study of an urban district in Finland

The world impact of fossil fuels on air pollution is responsible for several millions premature deaths every year. The present study analyses the decarbonization of district heating (DH) and cooling (DC) networks by the integration of ground source heat pump (GSHP) within an urban district in southwestern Finland, in terms of technoeconomic feasibility, efficiency and environmental impact. A novel mathematical modelling for GSHP operation and energy system management is proposed and demonstrated, using hourly-based data for heating and cooling demand. Hydrogeological and geographic data from different Finnish data sources is retrieved in order to calibrate and validate a groundwater model. Three different Scenarios for GSHP operation are investigated, limited by the maximum pumping flow rate of the groundwater area. The additional pre-cooling exchanger in Scenario 2 and 3 resulted in an important advantage, since it increased the heating and cooling demand covered by GSHP by 15% and 16% respectively as well as decreased the energy production cost by 4%. Moreover, Scenario 3 was solved as nonlinear optimization problem resulting in 4% lower pumping rate compared to Scenario 2. Overall, the annually balanced GSHP management in terms of energy and pumping flows, resulted in low long-term environmental impact and is economically feasible (energy production cost below 30 €/MWh).