Session VIII GEOTHERMAL ENERGY RESOURCE IN SLOVAKIA – PROSPECTIVE CHALLENGE FOR DEVELOPMENT Ivan Kočiš, Tomáš Krištofič: ULTRA DEEP DRILLING TECHNOLOGIES FOR GEOTHERMAL ENERGY PRODUCTION

At present, society and economics handle two main global ranges of problems in the long term, namely: 1. Energy increase of energy carrier prices, impaired safety and self-sustainability, reduced imports, replacement by own resources. 2. Environment environmental hazard due to climate changes, increasing level of emission gases, fight with CO2 in production of energies. With serious approach of governments to the above problems, both factors evoke imperative demand of technologies for production of ecological energies, primarily of electric energy. Substance of the presented research and development is the technology for realization of geothermal bores approximately 8 to 10km deep. In such depths, rock temperature reaches 200°C to 400°C practically all over the world. In this depth, thermal capacity of 1km3 is about 1017J (when cooled down by 100°C); this is comparable with annual demand for Slovakia. With real consumption of approximately 20 to 40MW the capacity of the same bore would be sufficient for several hundreds of years. Deep geothermal energy is available anywhere, there are no emissions (CO2), represents serious candidate for base load 24/7 electricity production and is scalable according to the local needs. The main obstacle for utilization of the vast energy reserves is price rising exponentially per 1 km of bore depth in present-day boring technology. Costs of such bores cannot be considered as a basis of repeated projects in most territories of the world. Thus, intense research and development of new deep drilling technologies is necessary. There are approximately 25-30 researched drilling technologies, but none of them gave desired economic and technical parameters for 5-10km depth. The technology must be compatible with extreme conditions at such depth (pressure up to 1000 bar and temperature between 400°C and 600°C) and very hard rock like granite. Presented radically innovative concept of drilling and transport of energy and material is protected by patents and being a basis of a know-how based upon innovative utilization of proven technologies. The method is suitable primarily for extreme pressure and temperature conditions, and has all pre-requisites to meet the basic requirement – linear price growth with bore depth. The concept was presented during Conference of the 6th EU Framework Programme "Engine", aimed at ultra deep geothermal energy and related research within future 7th Framework Program projects. The concept aroused considerable attention and interest in participation in future projects.