Summary

There were presentations held on the topics of global trend of geothermal development, Enhanced (Engineered) Geothermal System (EGS), and situations of geothermal utilization in Iceland and Japan.

After the presentations, discussions were held on a number of topics, including future of geothermal technologies, sustainable operation of conventional geothermal systems and measures to promote innovation for geothermal technology.

It was agreed upon the panelists that geothermal energy is one of the most reliable sources of renewable energy. Icelandic experience shows that strategic maintenance enables to keep high capacity factor of geothermal power plants in a long term.

As one of the future technologies, EGS received an extensive amount of recognition. Results of EGS demonstration in the USA and Japan were presented. Even though there still remain some technological hurdles, new technologies such as zonal isolation technology, which may achieve higher productivity, have been recently developed. It was pointed out that in order to advance EGS technology, there needs to increase the number of demonstration projects in different geological conditions and to widely share the findings through international research networks.

Discussion pointed out that it is also important to make the most efficient use of conventional reservoirs and enhance their sustainability. Latest technologies, such as geothermal and solar PV hybrid system, cogeneration, and use of low temperature geothermal energy by binary cycles, must contribute to broader and more efficient use of geothermal energy. New challenges including deep drilling aiming at supercritical fluids in Italy and Iceland were also presented.

Through the session, the significant potential to further develop geothermal energy was recognized among all the panelists. It was confirmed as well that technological innovation and development of new systems are needed to realize such potential.