Borehole thermal energy storage (BTES) as backup systems in district heating and cooling contexts: results from numerical simulations

Abstract

The current energy crisis since February 2022, have led governments to put in place short and long-term measures aimed at shielding consumers from the direct impact of the rising energy prices across Europe, and to counteract the continuous economic volatility. The pressure is high for finding solutions to reduce energy imports, and fight against climate change impacts. The numerous debates on climate change such as the COP27 are pushing for a greater acceleration in decarbonising the energy sector. Low carbon sources such as geothermal energy can substantially decrease energy consumptions and costs, especially if included into decarbonized heating and cooling grids (Chicco et al., 2022). The use of geothermal energy for thermal energy production and storage in district heating and cooling (DHC) grids may also be a key element in overcoming short-term energy peaks overcoming of the gap between energy supply and demand, which is still a challenge for the energy transition.  In this framework, underground thermal energy Storage (UTES) systems can be a key element for efficient operation of heating and cooling grids. Here, we present a study aimed at evaluating the performance of one of the most promising underground thermal energy storage systems, which uses boreholes to store heat or cold (BTES). Aimed at testifying the replicability of the used methodology, we replicated the same workflow already presented in Chicco and Mandrone (2022) but on a different area in northern Italy, with similar hydrogeological and thermo-physical characteristics. Based on real field data, the study focused on numerical simulations aimed at understanding how these technologies can be used as backup systems, or when the energy demand overcomes that supplied by conventional heating systems. Obtained results proved again how the integration of these technologies in DHC contexts can contribute to greater energy and economic savings, showing that BTES are very flexible to meet both the base and peak load requests for several users.Chicco, J.M.; Antonijevic, D.; Bloemendal, M.; Cecinato, F.; Goetzl, G.; Hajto, M.; Hartog, N.; Mandrone, G.; Vacha, D.; Vardon, P.J. Improving the Efficiency of District Heating and Cooling Using a Geothermal Technology: Underground Thermal Energy Storage (UTES). In New Metropolitan Perspectives; Calabrò, F., Della Spina, L., Piñeira Mantiñán, M.J., Eds.; NMP 2022; Lecture Notes in Networks and Systems; Springer: Cham, Switzerland, 2022, 482, 1699–1710. https://doi.org/10.1007/978-3-031-06825-6_164Chicco, J.M.; Mandrone, G. Modelling the Energy Production of a Borehole Thermal Energy Storage (BTES) System. Energies 2022, 15, 9587. https://doi.org/10.3390/en15249587