Ozekatashina Power Station
This power station is small hydropower station which started to operated by the Tokyo Electric Generation Co., Ltd in June 2023. This facility generates the electricity utilizing the steep of Katashina village in northeastern Gunma Prefecture and “Kurumazawa” water which flows into Katashina river. This is japan’s leading designed power station that the building is designed by an architecture Mr. Norihiko Dan and we are aiming to live with the local community through tourism, education and disaster prevention. We also set the naming rights.
Specifications of the power station
Address of the power station：Ooaza tsuchiide, Katashina-mura,Tone-gun, Gunma prefecture
River system and name of the river：Tonegawa river system, tributary of Katashina river Kurumazawa
Method of power generation：Run-of-river system (Waterway type)
Maximum water consumption：0.45㎥/s
Commencement of commercial operation：June 29, 2023
Architecture in haromony with the valley of Kurumazawa
Kurumazawa, situated at Ozekatashina village, is a clear stream which flows refreshing water between mountains.
This small hydropower station which utilizes rich water resources surrounded by Shirane mountain and Hotaka moutain, flows back the stream water as a precious water resouces for the downstream side after using as renewable energy sources. As a clean energy facility keeping the beautiful nature environment and open to the local community, this power station is designed to be a symbiotic model of human and nature.
Purely domestic source of renewable energy: “hydropower”
Hydropower is suitable for Japan which has many precipitous terrain and bounty of water. The mechanism is inside hydrological circulation of nature, utilizing the water and it convert the potential energy to electric energy. Among the renewable energy, hydropower allows to generate the electricity day and night, throughout the year and higher capacity factor is one of its characteristics.
About small hydropower
This power station is classified as small hydropower under 1000kw, which is relativerly small scale among the hydropower. Its power generation system which using water flow to rotate the turbine is the same but small hydropwer does not need the large facility such as dam and using water for generate the electricity without stopping the water flow. We called this as “run-of-river type” and this is easier power generation way to get hermony with the nature.
Furthermore, in this power station we buried the waterway to minimize the inflence into the environment while taking into consideration the scenary.
Advantages of run-of-river type hydropower
1. It fits the japanese natural features
In Japan, we have many precipitous terrain, so it is said that we already developped every possible large scale hydropower station but it remains the potential terrain to develop the midium and small scale hydropower station.
2. Sustainable water energy
The river water goes back to the river after using to generate the electricity without cosuming. In the lower section of river, it is possible to reuse repeatedly for power generation.
3. Environmental impact is small
It does not need a large-scale construction work, the amont of CO2 emission is relatively low during the counstruciton, so among the renewable energy, the amount of lifecyle CO2 emission is also low level.
The energy source is Kurumazawa water
The water which is the source for generating the elecrticity in this power station is the water of “Kurumazawa”. We intake the river water from “weir” which keeps back the water is led to the power house via “head tank” through “penstock”, it . We utilize a gradient to generate pressure enegy. The water coming from “penstock” into “turbine” become the power to rotate “runner” and it rotate also “generator”which coonected with the same axle. The water passed the turbine goes back to the river via “outlet”
Capacity of Ozekatashina Power Station
Maximum output 678kW：The image is that we throw more than 2 bathtubs of water from the place which is higher than the building of Gunma prefectural office every second.
Annual energy generation 3,700,000kWh：Energy which used annually by 870 ordinary homes
Turbine plays a role of convert the water’s potential energy into rotational energy. The power station install Italian Pelton turbine. Pelton turbine is one of impulse water turbine. To generate the electrcity, the water,which coming from higher point to power house through the penstock, discharged from injection nozzle powerfully strikes to bowl shaperd backet of runner and rotates it, then also rotates the generator which connected to the turbine .
“Tourism”, “Education” and “Disaster prevention” are new roles for a power station
This power station has a mission to live with the local communicity as well as the hydropower generation.
Through the role of “Tourism””Education” and “Disaster porevention”, and as an existance open to the local commuity and required by all the people, we aime to contribute to a sustainable society working with the local community.
Place for tourism：As a tourism spot, there is “a café space” in the power station area for not only people enjoy the shapes of the building, but they also take a rest while viewing the mountain steam.
Place for learning：As we installed the window on the building of power staion, it is always possible to see the inside which is not usually the case. When people goes to inside the power station, they can identify the rotating runner through the window of the turbine.
Emergency power supply：We install “portable buttery” for the people of this area as emergency power supply when the electriciy supply to the local area stops at the time of disaster.
Future-oriented stationing design
This power station is at an elevation of 950 meters, located in the valley of Kurumazawa stream, srrounded by planted forest with japanese cedar, japanese cypress and larch etc. Before the construction work is started, we did the research of the constitution of the forest based on the biodiversity. Then we did the selection of the tree species for vegitation, green zone block planning, and vegitation of regional spicies. 30 years later, it is planned to be like the figure.
The canopy plan for 30 to 50 years later.
Creatures you might find around the facility
Oze is made by great blessings of nature Katashina village, it’s history has been forming with the benefit. Oze is one of the national famous place for alpine plant and marsh. Then it is blessed with amazing natural environment through the 4 seasons such as mountain scenary with Hotaka mountain and Shirane mountain and many surrounded mountains and beautiful lacs of Suganuma and Marunuma.
Even around this power station, we can see various animals and plants living in the rich natural environment.
Katashina spring water and hydropower station
In Katashina village, there is an abundance of spring water which is made by a wealth of nature. This is not only the great quality but also is certified as “Japan’s 100 remarkable waters in Heisei era”, since environmental activities such as clean activity and vegitation and protection of the moutain forest by villagers was recognized. At Katashina village, they use this spring water as a tap water. And TEPCO group has lots of hydropower station utilzing this area’s water.