Ultra Deep Drilling Technologies for Geothermal Energy Production

Abstract

Substance of the presented research and development is the technology for realization of geothermal boreholes approximately 6 to 10 km deep. In such depths, rock temperature reaches 200°C to 400°C practically all over the world. In this depth, thermal capacity of 1 km3 is about 1017 J (when cooled down by 100°C); this is comparable with annual demand of Slovakia. With real consumption of approximately 20 to 40 MW the capacity of the same borehole would be sufficient for several hundreds of years. Deep geothermal energy is available anywhere, represents the most serious candidate for a base load 24/7 electricity production, there are no CO2 emissions and is scalable according to the local needs. The main obstacle for utilization of the vast energy reserves is the price rising exponentially per 1 km of a borehole depth in present-day drilling technologies. Costs of such boreholes 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.