Estimating Low-Enthalpy Geothermal Potential for District Heating in Santiago Basin (33.5°S), Central Chile

Abstract

This work shows results of a regional scale estimation of low-enthalpy geothermal resources in Santiago basin (33.5°S), located between Coastal Range, and Andean Range in central Chile. The purpose of this work is to identify promising areas for the development of the direct use of this non-conventional renewable energy. The estimation is based on soil thermal properties, and hydrogeological parameters using Geographic Information System (GIS). To estimate the low-enthalpy geothermal potential for district heating, a Borehole Heat Exchanger (BHE) coupled with Heat Pump is assessed to supply the energy demand equivalent to the required to heat a standard Chilean house. The main barrier for this direct use of geothermal energy is the depth to be drilled to implement a BHE. The depth to be drilled is estimated based on specific Heat Extraction (sHE) of sediments in watt per meter. Results show that the most important parameters controlling the meters to be drilled to implement a BHE are static level depth, and groundwater flow velocity. In our case the meters to be drilled range from tens of meters to a little more than one hundred meters.