FREAパンフレット（英語）

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Subduction zones100- 200kmAbout 5km2-3kmShallower than 1 kmNatural geothermal reservoir (presence of steam and hot water)Hot spring resourcesInsufficient scientific understanding on relationship between hot springs and geothermal power generationDifficulties in identifying geothermal resources within very locally distributed natural cracksRelatively small-scale natural reservoirs in Japan (sustainable production capacity: 20–30 MW)Insufficient understanding of various phenomena that occur inside and outside a reservoirPossibility that there is a large amount of supercritical geothermal fluid in the cooling magmaInvisibility of the undergroundRisks of boreholes with low productivityMagma generated in the subduction　zone (supercritical conditions with　temperatures higher than 400–500℃ therein)2015FY2020FY2030FYDevelopment of monitoring and simulation technologiesDemonstration of the potential for developing supercritical geothermal resources originating from the subduction zoneDerivation of a high-resolution and high-reliability method for reservoirmonitoringRealizing innovative large-scale geothermal power generationBuilding a method to implement geothermal power generation in into societyTechnical support for companies in the disaster-affected areasResearch and development of innovative technologies originated from JapanSecuring the international advantages of JapanPromoting geothermal energy-related industries in the disaster-affected areasDevelopment of a geothermal energy simulatorDirect contribution for increasing amounts of power generation and for maintaining its sustainabilityImproving the reliability of geothermal power generationIntegrated understanding of a geothermal systemHigh-temperature hot springsStratovolcanoCalderaLow permeability rockMagma reservoirSlabBrittle zonelithostatic pressure equilibriumHot fluid upward flowTarget of this studyHydrostatic equilibriumNatural hydrothermal system14Research TargetThe team is conducting various projects commissioned by the national government, private companies, and others to establish the proper utilization of geothermal energy in Japan. The team also conducts basic studies in geosciences to improve the scientic understanding of geothermal systems. Since the area underground is invisible and the properties of geothermal resources largely depend on the specic area, it is very important to acquire actual data in the eld for conducting geothermal studies. The team therefore conducts eld experiments, monitoring, equipment testing, etc. at many eld sites mainly in the Tohoku region.The team mainly aims to accomplish the following goals:●Understanding and visualizing the phenomena that occur in the reservoir by developing a sensing system for monitoring geothermal energy using microelectromechanical systems (MEMS), optical bers, etc., and by developing advanced analysis technologies such as transient multicomponent signal processing and integrated interpretation.●Compiling huge amounts of geothermal resource information possessed by AIST into an advanced database, presenting optimal development methods, and achieving coexistence with hot springs by developing a geothermal energy simulator.●Developing an optimal reservoir creation and control technology using hydraulic stimulation and uid injection, through laboratory tests and numerical simulations. This allows us to derive a universal development and utilization method.●Exploring the possibility of developing supercritical geothermal resources originating from the subduction zone and making it available for large-scale base load power generation by around 2050.The team is conducting research and development for the sustainable use of geothermal energy on a suitable scale and in a proper style according to underground conditions and social situations with the following catch-phrase: “Proper use of geothermal energy.” In the short term, the team aims to make a direct contribution to sustainable power generation and to increase its amount by developing a monitoring system for the coexistence of geothermal power generation with hot springs and advanced monitor-ing of changes in the reservoirs.In the long term, the team will make geothermal energy available on a large scale as a base load power source by developing an innovative power generation technology through the use of supercritical geothermal resources originating from the subduction zone and the development of a method for using geothermal energy in society.Research OutlineNeed for studying and developing geothermal energyFREA’s Geothermal Energy Research RoadmapConcept of a supercritical geothermal systemDistribution of old calderas (Oyagi, 2003)The team has proposed the possibility of generating several tens to several hundreds of GW of power by exploiting a supercritical geothermal resource originating from the subduction zone. The team is drawing up a research plan to make this geothermal resource available as a base load power source by around 2050.Geothermal Energy Team‒ Technologies for Eective and Sustainable Use of Geothermal Resources ‒Japan has many volcanoes and a vast amount of geothermal energy that can contribute to stable power without being aected by the weather conditions. Geothermal energy has the potential to provide the base load power. lBlessings of the EarthBlessings of the EarthThe results of seismic and other analyses suggest the existence of magma-originated volcanic complexes containing about 1% of the supercritical uid beneath the old volcano and caldera (4‒5 km). There are more than 50 old volcanos and calderas in the Tohoku region.