Feasibility of Shallow Geothermal Installations for Cooling Purposes in Tropical Climate

Geothermal energy has been widely recognized as a renewable, clean, cost-effective, source of energy that can be an alternative to fossil fuels. Geothermal Heat Pumps (GHPs) are tools that can extract heat from subsoil, surface water bodies, or groundwater. In Colombia, geothermal energy is one of the least developed and known non-conventional renewable energy sources. To reduce the operating costs associated with the cooling at 3 °C of a flower’s preservation room in the municipality of La Ceja, a surface water source heat pump (SWHP) and a horizontal ground-coupled heat pump (GCHP) were evaluated as energy alternatives. The temperatures in a rainwater harvesting pond and soil were monitored to analyze their potential as a heat sink for the proposed geothermal installations. The water temperature varied with outdoor conditions due to the shallowness of the pond. In contrast, the soil temperature was characterized by an almost constant value. Based on the data collected, it is determined that only during a portion of the day of 4 h (9:00–13:00) suggesting the efficiency of a SWSHP system is higher than the traditional refrigeration system currently used. This result indicates that a single SWSHP is not sufficient to provide the required cooling load. Therefore, a horizontal GCHP is suggested as an alternative installation to be used. This work promotes the use of geothermal resources in Colombia and is also a valuable contribution for the entire Caribbean and Latin America region, where GHPs are not commonly used.