Towards more widespread use of renewable enagy

Towards more widespread use of renewable energy
-Harnessing geothermal, ground source, hydroelectric and solar energy-

Interest in energy-related issues has increased in the wake of the Great East Japan Earthquake. We have been active in the renewable energy field for more than a century. In line with our long-term management policy of “supporting a recycling-oriented society,” we are promoting the use of diverse renewable energy sources in Japan.

Increasing use of diverse renewable energy

Makoto Shibata Makoto Shibata
General Manager, Energy Business Division, Mineral Resources & Recycling Business Unit

We have a long history of involvement in the renewable energy business, dating back to Nagata Hydroelectric Plant established to supply electricity to our Osarizawa Mine (Kazuno City, Akita Prefecture) in 1898. We later harnessed the technology built up in the mining business to go into geothermal development. In 1974, we started operations at our Ohnuma Geothermal Power Plant in the same area.
We have a high level of technological expertise and vast experience that enables us to provide one-stop-shop geothermal solutions ranging from underground investigation to facility construction, power generation, operation and management, and this technology and expertise is also being applied in the geothermal heat pump systems business of our group company Mitsubishi Materials Techno Corporation.
In line with our corporate philosophy of “establishing a recycling-oriented society,” we intend to promote the use of renewable energy from a long-term perspective. In our geothermal and hydroelectric businesses, we aim for stable profit by promoting the upgrade of power plants and new projects and, since our entry to the photovoltaic generation business in 2013, we have brought three plants online in Japan, and are also conducting investigations for a new plant.

Our renewable energy projects Power plant locations

Power plant locations

CO2 reduction through renewable energies

CO2 reduction through renewable energies * The above ļ¬gures have been recalculated based on the latest data published by the Central Research Institute of the Electric Power Industry (2010).


Geothermal Power Business

Outstanding technology for harnessing precious resources

Ohnuma Geothermal PlantOhnuma Geothermal Plant

Schematic of directional drilling

Schematic of directional drilling

In many volcanic zone, high-temperature magma, which has enormous thermal energy, is present several kilometers below the surface. Geothermal power generation uses this thermal energy as water vapor (steam) to make electricity. Owing to its many active volcanoes, Japan has the world's third largest geothermal potential, but just 2% of these are considered to be actually used for power generation. It is estimated that geothermal power generation emits 13 grams of carbon dioxide per kWh, which is at least 700 grams per kWh less than fossil fuel power (Central Research Institute of Electric Power Industry (2010)), and geothermal power is expected to become more widely used, especially in the wake of the Great East Japan Earthquake.
The construction of geothermal plants requires prolonged and careful investigation, capital investment and highly advanced technology. Leveraging our investigation technology built up through the development of underground resources, we have been involved in the development and operation of geothermal plants for around half a century. We are currently participating in the operation of two geothermal plants in Hachimantai, Kazuno City, Akita Prefecture, namely Ohnuma Geothermal Plant (rated output: 9,500kW; brought online in 1974) and Sumikawa Geothermal Plant* (rated output: 50,000kW; brought online in 1995), and are helping to provide a stable supply of clean energy.
In recent years, with the establishment of the feed-in tariff scheme and promotion measures for renewable energy, social needs are much stronger and the business environment is also showing signs of improvement. We will make the most of this opportunity and push ahead with new geothermal development projects in areas including the Wasabizawa area of Akita Prefecture, the Appi area of Iwate Prefecture and the Musadake area of Hokkaido.

*At Sumikawa, we are involved steam supply.

Valuing communication with local residents

Kazuharu Ariki Kazuharu Ariki
General Manager,
Geothermal & Electric Power Dept., Energy Business Division, Mineral Resources & Recycling Business Unit,

There are many requirements for the development of geothermal resources, including temperature, geological settings, and the amount and properties of geothermal fluid (water), and the lead time from exploration to operation is around 10 years. The Japanese government is currently examining shortening the environmental impact evaluation period, and we are also aiming for early commercialization in projects currently underway, including our Wasabizawa and Appi projects. The development of mutual trust between ourselves and local communities, especially local hot spring business operators, is extremely important for facilitating the progress of projects. We monitor the characteristics of hot springs on a regular basis, reporting to local governments and hot spring business operators and providing technical assistance. We also endeavor to contribute to and communicate with the local community, establishing a committee to deliberate on the impact on hot springs and providing the hot water supply management association with hot water produced using steam from Ohnuma Geothermal Plant.


Geothermal Heat Pump Systems (GSHP)

Seeking to promote use through reliable solutions

Tokyo SkytreeTokyo Skytree using the borehole method GSHP

Coiled horizontal heat exchangeCoiled horizontal heat exchanger laid in lower
floor slab of railway tunnel

Like geothermal energy, ground-source heat is also one of the renewable energy like . With a heat source that stays almost constant throughout the year and is different from outdoor air temperatures, geothermal heat pump systems used for air-conditioning and snow-melting are extremely energy efficient and effective at reducing CO2 emissions. They are also highly regarded as countermeasures against the so-called heat island phenomenon, because they do not discharge heat to the outdoor air.
Mitsubishi Materials Techno Corporation leverages investigation and drilling technologies used in geothermal power generation to provide reliable solutions for geothermal heat pump systems, covering everything from investigation to design, construction and maintenance. Mitsubishi Materials Techno Corporation has built up a track record of constructing systems throughout Japan and its systems have been used in many projects including Tokyo Skytree and the quadruple trucking project of Odakyu Line. In the quadruple trucking project of Odakyu Line, the system is expected reduce annual CO2 emissions by 32% and reduce annual running costs by 33% compared with conventional air-conditioning systems.

Developing and promoting diverse construction methods

Kazutoshi Sugiyama Kazutoshi Sugiyama
General Manager, Drilling Dept., Natural Resources, Environment and Energy Engineering Division,
Mitsubishi Materials Techno Corporation

In fiscal 2010, our geothermal heat pump system was installed in the District Heating and Cooling System for Tokyo Skytree. This drew attention to the GSHP and also raised our public profile. Ground-source heat is being more widely used in the USA, Europe and China and is also expected to become more widespread in Japan in the future. We have developed three construction methods for setting up the ground-heat exchanger: the borehole method, the pile welding method and the horizontal method, and will continue working to make geothermal energy more widely used in the future by reducing cost and other means.


Hydroelectric Power Businesses

Passing on history to the next generation

Komatagawa No. 4 Hydroelectric PlantKomatagawa No. 4 Hydroelectric Plant
(Akita Prefecture)

Lake TaiheiLake Taihei (Akita Prefecture)

Our first foray into using renewable energy was our hydroelectric power business. The Nagata Hydroelectric Plant, which we put into operation on the Kumazawa River (Yoneshiro River System) in Kazuno City, Akita Prefecture in 1898, supplied the power to run our Osarizawa Mine, which was operating in the same area at the time. Later, to meet growing demand for power at our Osarizawa Mine, we expanded our Ikari Hydroelectric Plant (began operations in 1907) on the Yoneshiro River and built the Oyu Hydroelectric Plant and four hydroelectric plants on the Komatagawa River, in a bid to expand our own private power generation facilities. In1962, our power plants on the Komatagawa system began supplying power to our Akita Refinery through our own private transmission lines, but began supplying power to electric power company directly after we stopped refining zinc in 1999.
Hydroelectric power generation, which uses the energy created by falling water to produce electricity, is attracting renewed attention as a clean energy that discharges few CO2 emissions. We see hydroelectric power as an energy source that is indispensable to local communities and are implementing initiatives for the stability of supply and operations, including the upgrade of existing facilities and the construction of new power plants, to pass our heritage of hydroelectric power business, which is more than a century old, onto the next generation.


Photovoltaic Power Business

Making use of idle land to expand Photovoltaic power plants throughout Japan

Irigama photovoltaic power plantIrigama photovoltaic power plant
(Kurihara City, Miyagi Prefecture)

The Mitsubishi Materials Group's commitment to its renewable energy business is backed by a long history and an extensive repertoire of technologies and expertise. In response to increasing social needs in recent years and changes in the business environment such as the feed-in tariff scheme, we are further expanding our renewable energy business.
In 2013, we expanded and strengthened our business lineup through the addition of our photovoltaic power generation business, which make use of our idle land. As a joint venture with Mitsubishi UFJ Lease & Finance, we began constructing power plants in four locations: Irigama, Makabe, Fukui and Torigoe. The total area for the site will be approximately 230,000 m2, and the total power plant capacity will be 16.4 MW. Our Makabe and Fukui power plants were brought online in December 2013, our Torigoe power plant came online in April 2014 and the remaining Irigama Plant is also expected to come online during fiscal 2015.
All the power generated is sold to local power companies, but we are also examining other business models, including supplying power to our plants and surrounding areas in the future, and we plan to continue investigations for new plants on idle land.

Fukui photovoltaic power plant Fukui photovoltaic power plant
(Fukui City, Fukui Prefecture)

Makabe photovoltaic power plant Makabe photovoltaic power plant
(Sakuragawa City, Ibaraki Prefecture)

Supplying around 70% of total rated renewable energy output in Kazuno City, Akita Prefecture

In Kazuno City, Akita Prefecture, we operate 10 hydroelectric plants (total rated output of 22.525 MW) and one wind farm (total rated output of 7.65 MW) in addition to our Sumikawa and Ohnuma Geothermal Plants (total rated output of 59.5 MW) and our Nagata, Ikari and Oyu hydroelectric plants on the Kazuno River System (total rated output of 3.36 MW). The total rated renewable energy output of these power stations is 93.035 MW and we generate electricity far exceeding total energy demand in Kazuno City (population of around 37,000). According to the Sustainable Zone Report 2013 (Kurasaka office of Chiba University and Institute for Sustainable Energy Policies, 2013), Kazuno City ranks 20th out of all municipalities in Japan based on nergy self-sufficiency, with an energy self-sufficiency ratio of 325.11%*, and we supply around 70% of Kazuno City's total rated renewable energy output.

* This figure is only an estimate calculated based on the amount of renewable energy generated within Kazuno City and demand within the city, and it does not mean that all the energy is actually consumed in Kazuno City.

Our power plants within Kazuno City and rated outputs

  Name of power plant Rated output
Geothermal Power Generation Tohoku Electric Power
Sumikawa Geothermal Plant
Ohnuma Geothermal Plant 9.5MW
Hydroelectric Power Generation Nagata Hydroelectric Plant 0.6MW
Ikari Hydroelectric Plant 1.8MW
Oyu Hydroelectric Plant 0.96MW

Total rated output of power stations in Kazuno City and breakdown

We supply approximately 70% of the total rated output.