Geothermal Energy Utilization in Slovakia: First Insights from Sustainability Perspective
Branislav FRIČOVSKÝ, Ladislav VIZI, Daniel MARCIN, Radovan ČERNÁK, Veronika BLANÁROVÁ, Zuzana UJJOBBÁGYOVÁ, Dušan BODIŠ, Katarína BENKOVÁ, Ondrej PELECH, Klement FORDINÁL
[Dionyz Stur State institute of Geology, Slovakia]
Production of geothermal energy is regulated through multiple legal tools, as is the Act No. 569/2007 Coll. (Act on Geology), Act no. 364/2004 Coll. (Act on Water) or Act No. 538/2005 Coll. (the Spa Act); rather with only a little relation to enactments of some effect on promotion of renewables contribution in primary energy generation (e.g. the Act No. 309/2009 Coll.) and their market (e.g. Act No. 521/2012 Coll., Act No. 609/2007 Coll., Act No. 555/2005 Coll. etc.). Although geothermal energy is repeatedly denoted renewable or sustainable energy resource within (anyhow mixed both the terms are), there is no legal form controlling energy and thermal potential balance aspects in sustainable use of the resource. The paper represents tentative results of geothermal reserves booking carried individually on recently delineated geothermal water bodies (GWBs) according to mandatories provided in EU Directive No. 2006/60/ES – the Water Framework Directive (WFD) applying Monte Carlo simulation individually to USGS volume method combined with recovery factor R0 definition, the latter combining production efficiency and effective reservoir volume principles on a unified time scale, i.e. tprod = 40 years and tprod = 100 years, with unified reference temperature of Tref = 15 °C for GWBs without and Tinj = 40 °C for GWBs with considerable reinjection. Then, the concept of resource capacity ratio with several modifications has been used to track GWBs where longevity may be questioned for prolonged period of production and to assess sustainable thermal potential. For 31 GWBs, probable reserves are assessed for Rpb = 6,716 MWth and Rpb = 2,686 MWth respectively, considering short- and long-term balance. For tprod = 40 years, GWBs may be operated at a current mean yearly thermal output (Pth = 67.6 MWth). Sustainability is, however, questioned whether prolonging the production period towards 100 years, or increasing thermal output up to installed capacity at 3 to 10 GWBs respectively. At recent installed capacity (229 MWth), there is likely 1,187 MWth (tprod = 100 years) or 2,750 MWth (tprod = 40 years) developable not compromising sustainability of thermal production (Pth(S)), resulting in the total sustainable thermal potential of Pth(S*) = 1,416 MWth and Pth(S*) = 2,979 MWth respectively. In fact, the potential is mainly cumulated in closed systems of complicated reservoir chemistry involving reinjection consideration.
|        Topic: Sustainability and Climate Change||Paper Number: 05023|