Mitsubishi Power, a subsidiary of Mitsubishi Heavy Industries (MHI) Group, said today that it has completed its renovation of the Otake Geothermal Power Station, located in the Kokonoe-machi, Oita Prefecture. The plant is operated by Kyushu Electric Power Company.
Commercial operation of the renovated facility began in October 2020. The power supply generated by the steam turbine installed as part of this renovation project will curb CO2 emissions, and contribute to a decarbonized economy.
This renovation project was
conducted under an engineering, procurement and construction (EPC) contract by
a joint venture comprising Mitsubishi Power, which supplied the steam turbine,
Mitsubishi Power Industries Co., Ltd., which handled the supply and
installation of auxiliary equipment, and Mitsubishi Electric Corporation, which
supplied the generator and electrical facilities.
The power generation system utilizes a “double flash and dual
pressure” method, the first of its type in Japan. This allows for stable
operation of the steam well and efficient use of geothermal resources, and has
increased the power output by two megawatts (MW) compared to the previous
facility, to 14.5MW. Construction was completed two months ahead of schedule
from the plan when work began in May 2019, allowing for the start of commercial
operation in October.
In the double flash and dual pressure method, high pressure primary steam from
a powerful production well, and low-pressure secondary steam from a weak
production well, are supplied to the steam turbine. Steam is further obtained
by lowering the pressure of the hot water extracted from the primary steam,
which is then used as secondary steam.
Geothermal energy utilizes the heat energy of the magma chamber inside the
earth, and because no combustion takes place above ground, little CO2 is
emitted into the atmosphere, making it an effective method of power generation
for curbing global warming. Further, because geothermal power is a type of
renewable energy that makes use of the enormous heat energy in the earth’s
interior, it is not subject to the cycles of season, weather, or time of day,
offering a high availability factor nearly on a par with that of thermal power.
Kyushu Electric Power’s Otake Power Station began commercial operation in
August 1967 as Japan’s first commercial geothermal power station. This plant is
also Japan’s first wet steam geothermal plant, and Mitsubishi Power’s first commercial
geothermal facility. Over more than fifty years in operation, this plant has
contributed to a stable energy supply, and the decarbonization (sustainability)
of society.
Mitsubishi Power has fulfilled orders for more than 100 projects in the geothermal
power field in 13 countries. With total plant capacity of more than 3,200 MW,
Mitsubishi Power holds a large share of the world’s geothermal power generating
capacity, and as a geothermal EPC provider, contributes to their stable
operation, it said.
