Site characterization for a study on shallow geothermal energy exploitation in Southern Brazil

Abstract

The energy crisis scenario currently going on in Brazil, along with the need to reduce greenhouse emissions, lead to an urgent need to design buildings with greater energy efficiency. Shallow geothermal energy surges as a sustainable alternative to reduce the electricity consumption in buildings related to air conditioning and water heating systems. In Brazil, the use of this technique is still incipient due to the lack of studies that demonstrate its viability in the country’s climatic conditions, as well as underground temperature and demand for acclimatization of buildings. The aim of the current work is to present a site characterization for the first geothermal energy investigation carried out in the Brazilian South region. This study is being conducted at the Geotechnical Experimental Site of the State University of Ponta Grossa, and this paper describes the physical, mineralogical, thermal and mechanical characteristics of this site, which comprises a thick layer of a lateritic sandy clay soil over a silty sand layer. The preliminary results of the ground temperatures are consistent with the common trends reported in the literature, showing more expressive oscillations near the ground surface, and becoming approximately constant at higher depths.