Recent Advances in Renewable Energy Technologies - Chapter 6: Underground energy: utilization of geothermal shallow heat pumps

Elsevier, Recent Advances in Renewable Energy Technologies, Volume 1, 2021, Pages 211-247
Gaoyang Hou, Zhengguang Liu, Meng Zhao, Hessam Taherian, Wei Jiang, and Diyi Chen

It is universally acknowledged that the shortage of traditional energy sources has become more prominent and a global challenge. Compared to traditional power generation, geothermal technology has several advantages: it is renewable, cheap, and easily constructed, which has generated widespread attention. Geothermal energy can be divided into shallow geothermal (0–200 m below the surface) and deep geothermal (200–3000 m below the surface) according to their depth. Due to the advantages of low cost and stable long-term energy performance (especially combined with heat pumps for building heating and cooling), shallow ground heat exchangers are receiving increasing attention. Open loop and closed loop are the main classifications of geothermal source heat pump (GSHP) systems. Two popular closed-loop ground loops are used in GSHP: vertical and horizontal types. This chapter gives a detailed introduction and discussion of two shallow geothermal utilization methods, summarizes the research progress of the two methods in recent years, and looks at the prospects of possible future development and utilization of geothermal energy.