January 17, 2023

December 23, 2022

Mitsubishi Materials Corporation

Commencement of Commercial Operation of the Komatagawa New Power Plant
- Akita Prefecture's First New Hydroelectric Power Plant in 69 Years Now in Operation -

Mitsubishi Materials Corporation today commenced commercial operation of the Komatagawa New Power Plant.
The Komatagawa New Power Plant was planned and constructed in order to increase the power supply through efficient operation of the Komatagawa No.1, No.2 and No.4 Power Plants(*1) in the Komata river water system centered on Moriyoshi Dam. By efficiently taking in water previously released as unused energy, the power generation capacity of the Komata river water system is increased by 2,860 kW, enabling an increase in annually generated power of approximately 13,400 MWh.

With the completion of the Komatagawa New Power Plant, use of the Komatagawa No.1 and No.2 Power Plants were discontinued in October 2022.

The Komatagawa New Power Plant takes water directly from the outlet of the Komatagawa No.4 Power Plant directly under Moriyoshi Dam (water intake: 13.0 m3/s) and leads water about 8.5 km downstream through a headrace tunnel to secure an effective head of about 90 m and generate 10,326 kW of power. All generated electricity will be supplied to society using the feed-in tariff (FIT) scheme for renewable energy. Efficient utilization of water resources can be realized by long-term, stable provision of renewable energy using the hydropower of the Komata river water system while preserving the river environment.

The power plant was constructed using the electricity (renewable energy) from the existing hydroelectric power plants to minimize the environmental impact. The CO2 reduction(*2) resulting from the operation of the Komatagawa New Power Plant is approximately 9,800 tons, which is equivalent to the amount of CO2 absorption by approximately 1,100 hectares of 40-year-old Japanese cedar plantation(*3).

Annual CO2 reduction from operation of the new plant: Calculated by MMC using the 2009 data sited in "Imamura & Nagano (2010). Comprehensive Assessment of Life Cycle CO2 Emissions of Power Generation Technologies in Japan, Central Research Institute of Electric Power Industry Report (Research Report)."
Calculated by MMC based on the information on the Forestry Agency website

MMC's hydropower business has a history of more than 100 years, and of the various renewable energy sources, provides an indispensable base load power supply to local communities. We will continue to contribute to the building of a recycling-oriented society by supplying stable power to local communities as an environmentally-friendly power supply.

Overall view of the Komatagawa New Power PlantOverall view of the Komatagawa New Power Plant
Inside of the Komatagawa New Power Plant building (water turbines and generators)Inside of the Komatagawa New Power Plant
building (water turbines and generators)

<Outline of the Komatagawa New Power Plant>

Komatagawa New Power Plant
1048 Rinpan
Kirinaizawa hoka 30 Kokuyurin, Moriyoshi, Kitaakita City, Akita Prefecture
River name
Komata River, Ani River tributary, Yoneshiro River system
Run-of-river system
Maximum discharge: 13.0 m3/s
Rated discharge: 4.17 m3/s
Effective head
91.50 m
Maximum output and power generation
10,326 kW and approximately 48,500 MWh (per year)
Horizontal-axis Francis turbine, 5,339 kW (2 units)
Horizontal-axis, 3-phase synchronous generator, 6.6 kV, 600 min-1
Location map Location map (Click the picture to see the enlarged image)

<Contact details for inquiries>

Corporate Communications Dep., Management Strategy Div.,
Strategic Headquarters : +81-3-5252-5206