Geothermal district heating modelling for typical Hungarian residential buildings in Debrecen

Abstract

The most important aim of this paper is to examine the technical possibilities to replace natural gas fired district heating system in Debrecen, E-Hungary, with geothermal energy. In order to present these challenges in a comparable way, the existing common residential buildings were grouped into seven subcategories and linked together theoretically, representing a system with diverse conditions. It has been established that hot geothermal water is able to replace a natural gas boiler in the range of 97-98% of the energy consumption, saving 91,000-111,000 m3 of natural gas yearly. The calculation identified, that the radiator system and the heat loss parameters of the residential buildings are the most crucial elements of the system. According to the presented scenario-B, which assumes only radiator replacement in more than half of the heat market, representing 325,000 net m2 , a decrease in total energy consumption is experienced in the range of 8-10%. On the other hand, scenario-C, which is assuming complex reconstructions for out-dated buildings, results in a significant 17-19% energy consumption savings, compared to Scenario-A (original case). In this regard, it is worth considering improvement to out-dated buildings within the heat market before starting geothermal energy development, to get an efficient, well-constructed system.