Rationalization of geothermal resources management in the Republic of Croatia - optimization of the sustainable energy resources

Proved geothermal energy resources in the Republic of Croatia are mainly result of oil and gas exploratory drilling as well as geothermal water drilling and testing that proved existence, in the Pannonian basin, mainly in the west and central part of the Drava depression, of thermal aquifers that could be used as alternative and sustainable power resources for the development of economy, tourism and balneological purposes. It is estimated that total domestic power potential is around 45.8 MWe and 812 MWt under presumption that geothermal energy is to be used oil the spot with power utilization lip to 30 degrees C and even larger utilization of AT, as accepted world practice, that is optimum and economically acceptable. A special emphasise is given to the project "Utilization of Geothermal Energy for Horticulture Upgrading in Zagreb" that meets those economical and technological parameters and provides for the shortest pay back period under the highest profit. At the same time, the Project represents a pilot project in the Republic of Croatia, providing focused and correct utilization of the geothermal energy, with possibility of gradual utilization of this power resource during technological cycle. Both technological systems Mladost Sports' Park and Zagreb Clinical Hospital, that are supplied with geothermal energy from the same area, have low degree of heat utilization that amounts to 1.21% for the entire field. Present production parameters are minor in comparison to the possible ones. That shows non -economical, non-rational and non-profitable production with high costs per unit of produced thermal power. In the paper is pointed out the necessity of favourable development of technological, legislative, institutional and economical basis that will encourage investments in upgrading the power efficiency and utilization of sustainable resources such as geothermal energy.