Abstract:
Geothermal energy production consists of two main types: low temperature or low enthalpy for temperatures below 150ºC, and
high temperature or high enthalpy systems for temperatures over than 150ºC. In mainland Portugal the most common ground
temperature varies from 20 to 40ºC, depending on the place where the geothermal boreholes are placed, which means that low
enthalpy systems can be considered. Currently the increased development of ground source heat pumps (GSHP) lead to a
continuous development and innovation of ground heat exchangers (GHE). The geothermal systems can contribute with savings
between 25-75% of the energy demands of buildings’ HVAC systems, making it a very appealing solution mainly in northern
and central Europe. The goal of this paper is to analyse the performance of a geothermal system installed in a department of the
University of Aveiro, in the center of Portugal. Firstly, an introduction about different GHE systems is done and after a real case
study is described and the methodology applied. To achieve the goal established, the building was analysed, audit and modeled,
and an energy simulation was carried out with EnergyPlus® 8.6 (EP) software. After the results obtained it can be concluded that
even in regions with mild climate as Aveiro, the geothermal system contributes with 34% of savings of the annual global primary
energy needs.