Quantifying the technical geothermal potential from shallow borehole heat exchangers at regional scale

RENEWABLE ENERGY

卷:165

Article

Walch, Alina¹  Mohajeri, Nahid²  Gudmundsson, Agust³  Scartezzini, Jean-Louis¹ 

[1] Ecole Polytech Fed Lausanne, Solar Energy & Bldg Phys Lab, Lausanne, Switzerland

[2] UCL, UCL Inst Environm Design & Engn, London, England

[3] Royal Holloway Univ London, Dept Earth Sci, Egham, Surrey, England

关键词: Shallow geothermal energy;    Borehole heat exchangers;    Potential estimation;    Numerical modelling;    Geographic information systems;   

DOI  :  10.1016/j.renene.2020.11.019

来源: Elsevier

【 摘 要 】

The extraction of shallow geothermal energy using borehole heat exchangers (BHEs) is a promising approach for decarbonisation of the heating sector. However, a dense deployment of BHEs may lead to thermal interference between neighboring boreholes and thereby to over-exploitation of the heat capacity of the ground. Here we propose a novel method to estimate the technical potential of BHEs which takes into account potential thermal interference as well as the available area for BHE installations. The method combines simulation of the long-term heat extraction through BHEs for a range of borehole spacings and depths and includes an optimisation step to maximise the heat extraction. Application of the method to a case study in western Switzerland, from an available area of 284 km2, yields an annual technical potential of 4.65 TWh and a maximum energy density of 15.5 kWh/m(2). The results also suggest that, for a minimum borehole spacing of 5 m and a maximum borehole depth of 200 m, the cumulative installed borehole depth should not exceed 2 km/ha. The estimated technical potential can be used by urban planners for the techno-economic analysis of BHE systems and by policy makers to develop strategies that encourage the use of shallow geothermal energy. (C) 2020 The Authors. Published by Elsevier Ltd.

【 授权许可】

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