| Abstract |
The R&D programs for geothermal technology have been conducted since 1980 by NEDO, which was established after two oil crisis to increase oil-alternative energies. At the end of 2001, the total installed electricity capacity by geothermal power generation was 533MW in Japan, which was ranked sixth in the world. Six projects were carried out in 2001, including the development of technologies for exploration, drilling, production and utilization of unconventional geothermal energies. The R&D projects in NEDO are, however, being terminated at the end of current fiscal year (March, 2003) due to the review of the technology content and impact on industry by METI, which is the promoting organization for energy. NEDO's programs have greatly contributed to increasing oil-alternative energies and technical engineers in Japan. Geothermal projects, which are promoted by NEDO, are very challengeable. DHP must be operated at high temperature and high pressure in narrow space with high output and is recognized as a key technology for the development of the large-scale binary power plant in Japan. HDR project has overcome various difficulties for the HDR power generation and technologies developed in the NEDO project are utilized in the other HDR test fields. The long-term circulation test is ongoing with a 100kW binary generation. The technology to stabilize electrical output from geothermal power plant and to explore the area surrounding existing geothermal fields efficiently is being developed in the NEDO project. A reliable numerical model of geothermal field will be constructed using repeat and/or continuous geophysical monitoring and the history matching techniques. From the viewpoint of global environmental issues and long-term energy security, geothermal energy development is expected to be reevaluated in the near future. |