We stably generate environmental loading-reducing electric power through our Ohnuma Geothermal Plant and Sumikawa Geothermal Plant (steam supply only at Sumikawa, power generated by Tohoku Electric Power), both in the Hachimantai area of Kazuno, Akita prefecture. In fiscal 2016, we generated a total of 411 GWh of power, which is equivalent to a 300,000-ton reduction in CO2 emissions compared to oil-fired power.
Doing geothermal power generation business, we have to find out geological structure, in order to maintain continual and stable supplies of steam. We have continued to examine data since we started operations at the Sumikawa Geothermal area, so that we can re-analyze geological structures and take action accordingly. This has also enabled us to increase the amount of power we generate by maintaining stable operations.
Sumikawa Geothermal Plant
Ohnuma Geothermal Plant
In addition to operating existing power plants, we are currently carrying out new projects too. Yuzawa Geothermal Power Corporation, established jointly with Electric Power Development Co., Ltd. and Mitsubishi Gas Chemical Co., Ltd., started construction of Wasabizawa Geothermal Power Plant in May 2015. In October 2015, we established Appi Geothermal Energy Corporation in conjunction with Mitsubishi Gas Chemical Co., Ltd., and conducted an environmental impact assessment for the construction of a geothermal power plant in the Appi area of Hachimantai city, Iwate prefecture. We are also in the process of conducting joint studies with other companies in Musadake in Hokkaido, and Bandai-Azuma-Adatara area in Fukushima prefecture.
New geothermal projects
We have a long history of generating hydroelectric power. In Akita prefecture, we built seven hydroelectric power plants for the purpose of supplying enough power to run Osarizawa Mine and homes in the local area. Of those power plants, six are still operating today, selling on the power that they generate to power companies. We restarted work to upgrade two power plants in 2015 however, in order to deal with aging facilities at Nagata Hydroelectric Plant (Kazuno), which has been up and running for 128 years now, and at Komatagawa No.4 Hydroelectric Plant, which has been up and running for 62 years. This has enabled us to increase our generation capacity, while securing both stable operations and stable revenue.
Last year, the combined power generated by all six hydroelectric plants was 53 GWh, which is equivalent to a 38,000-ton reduction in CO2 emissions compared to oil-fired power. We are currently planning a new large-scale hydroelectric plant on the Komatagawa water system, in an effort to generate even more renewable energy.
Nagata Hydroelectric Plant
Reduction in CO2 emissions thanks to renewable energy
Having entered the solar power business in 2013, making effective use of idle group land, we have now built power plants in four locations as part of a joint venture with Mitsubishi UFJ Lease & Finance, in Makabe (Ibaraki prefecture), Fukui, Torigoe (Fukuoka prefecture) and Irigama (Miyagi prefecture). Our power plants in Makabe and Fukui were brought online in December 2013, followed by Torigoe in April 2014 and Irigama in January 2015. All facilities have continued to operate smoothly since then. We began building Yabuki Solar Power Plant in the town of Yabuki, Fukushima prefecture, in July 2015, and commenced operations at the plant on June 15, 2016. This takes our total to five plants, covering an area of approximately 334,000 m2, with a generational (modular) capacity of 24.7 MW.
Yabuki Solar Power Plant
Mitsubishi Materials Techno Corporation is actively working on research and development of systems capable of harnessing "ground-source heat" as a form of renewable energy. It has successfully developed commercial systems using the borehole, foundation pile and horizontal methods, with over 100 systems installed nationwide since 2003.
In April 2015, Mitsubishi Materials Techno installed an "open loop" GSHP system at its offices in Kazuno, Akita prefecture, in the hope that it would improve efficiency. Energy saving figures for that same year show that the new system reduced energy consumption by roughly half compared to a conventional air-cooled air conditioning system. The offices have a GSHP's "visualization" system, which features a simple display showing operating levels and other such information.
In February 2016, a Mitsubishi Materials Techno research initiative to develop systems to harness ground source heat using urban infrastructure was included in a research and development project spearheaded by the New Energy and Industrial Technology Development Organization (NEDO), aimed at developing technology to harness heat from renewable energies. As such, the company is now conducting research into low-cost GSHP systems that combine the SMW* system, which is commonly used in urban construction, with ground source heat.
* SMW system: Method of construction that involves taking soil (S) and mixing (M) it together with cement slurry onsite, to form a connected wall (W) in the ground.
Our Fifth Stakeholders' Meeting was held and we discusssed on the theme “Thinking about the future of renewable energy -The role to be played by the Mitsubishi Materials Group in its main business- .”