Brief Review of the Current Status and Trends in the Development of Geothermal Energy

The current state and development trends of geothermal energy are discussed based on an analysis of the materials of the World Geothermal Congress (WGC-2020 + 1) held in Iceland as well as articles published after this event. Promising directions and scales of use of geothermal resources in power generation, heat supply, and other areas of the economy are shown. A constant increase in the number and total capacity (by 27% over 5 years) of geothermal power plants in the world is noted, and statistical data on countries for 2015 and 2020 are presented according to the total installed capacity of geothermal power plants (GeoPP), the level of annual production of geothermal electricity, and the expected installed capacity for 2025. The location of the main geothermal power plants on the world map in 2020 is shown. The levels are considered risk and the amount of funding required at various stages of the creation of geothermal power plants in new fields, where the cost of building a power plant is 30% of the total cost of a GeoPP with drilling and well development. An analysis of the presentations on the power industry indicates that there is still significant interest in the use of binary power plants for the utilization of geothermal heat. As promising, the developments of new technological solutions for improving binary power plants based on the optimization of the choice of the working fluid and for improving the reliability of geothermal steam turbine plants by superheating the flash steam due to the use of a hydrogen-oxygen steam generator are presented. There has been an increase in interest in obtaining "green" hydrogen based on environmentally friendly geothermal power generation. The possibility of hydrogen production using electrolyzers, which use excess electricity at the GeoPP during periods of daily unloading, is shown.