Shallow geothermal energy applied to a solar-assisted air-conditioning system in southern Spain: Two-year experience

This paper describes a shallow geothermal system that was designed as an alternative to the cooling tower in a solar-assisted air-conditioning system installed in southern Spain (Almería). The core idea of this solar-assisted air-conditioning system is to cover the cooling and heating load of the Solar Energy Research Centre (CIESOL), minimising its environmental impact. In this study, the cooling mode was further investigated. The shallow geothermal system has been operating since May 2010, providing groundwater at 22 °C via a 20-m-deep supply well as a cooling carrier medium. The shallow geothermal system application improves the solar-assisted air-conditioning system’s efficiency, thereby reducing its electricity and water consumption. The results demonstrate that during one cooling period, the seasonal shallow geothermal system uses 31% less electrical energy than a cooling tower system. It also achieves savings of 116 m3 in water consumption throughout the summer period.

► We present a new solar-assisted air-conditioning system’s operation mode.
► This mode considers the shallow geothermal system action.
► It permits to save about 30% of energy consumption during one cooling period.
► It allows savings of 116 m3 of deionised water throughout the summer period.
► Shallow geothermal system was proved as a good alternative to the cooling tower.