出光興産における地熱事業の取組み

抄録

Idemitsu Kosan Co., Ltd. (Idemitsu) has been operating the explorations and productions of geothermal resources since establishing a new department and beginning coal, uranium, and geothermal businesses in 1977. The aim of this action was to develop alternative energy resources to oil and gas and alleviate the shortage of energy resources since the first oil shock in 1973.

Idemitsu picked out a promising prospect in Takigami area, Oita prefecture as a result of its nationwide explorations. After the additional explorations and production tests in the advanced stages, Idemitsu began to produce geothermal steam that was equivalent to 25,000 kW and supply it to Takigami Power Station operated by Kyushu Electric Power Co., Inc. in Nov. 1996. Since Jun. 2010, the output has been increased to 27,500 kW by utilizing surplus steam production.

In recent years, geothermal resources have been re-recognized as clean, renewable, and domestic energy resources in Japan and expected to alleviate the environmental and energy issues. Idemitsu launched on the post-Takigami projects for further development of geothermal resources based on its experience in Takigami. The prospects in Amemasu-dake area, Hokkaido prefecture and Oyasu area, Akita prefecture have been explored by Idemitsu in cooperation with the joint venture partners, INPEX CORPORATION and Mitsui Oil Exploration Co., Ltd. since 2011.