The tendencies of the development of geothermal energy technologies on the base of utilizing geothermal fluid of different temperature are studied. It is shown that in recent years there are an increasing number of countries where the growth of installed capacity of geothermal power plants is mainly due to the construction of power units with a binary cycle. It allows to expand the resource base of geothermal energy through the development of low-temperature geothermal sources, the total capacity of which exceeds the one of high-temperature resources. It is noted that the low-temperature geothermal sources are widely available and in fact can be utilized almost anywhere in the world. The analysis of the scale and geography of the application binary energy technologies for the development of geothermal resources are shown. The features of the use of organic working fluids in binary power plants are described. The basic principles of the optimal working fluid selection for binary plant are explained. The results of numerical modeling of the working fluid selection on the performance of binary power plants are presented. It is shown, that use of the hydrogen-oxygen steam generator in combined power plants can increase the effectiveness of geothermal utilization. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.