Overview
The Kazunogawa Pumped Storage Power Station is a major hydroelectric facility located near Kōshū in Yamanashi Prefecture, Japan. As a pumped-storage plant, it utilizes water as its primary energy source, functioning as a critical component of the regional power grid managed by TEPCO Renewable Power. The station is owned by TEPCO and represents a significant investment in Japan's renewable energy infrastructure, constructed at a total cost of US$2.2 billion. The facility is designed to accommodate four generators, each with a capacity of 400 megawatts, resulting in a total installed capacity of 1,600 megawatts (2,100,000 hp).
Currently, the station operates with three of its four generators in service, providing a total operational capacity of 1200 MW. Construction on the power station began in 1993, with the first generator commissioned on 3 December 1999. The second generator followed on 8 June 2000. The third generator became operational on 9 June 2014, which was six years earlier than originally scheduled due to increased power demand following the Great East Japan earthquake. The fourth and final generator is slated to be commissioned by 2024, which will bring the plant to its full designed capacity.
History and Construction Timeline
Construction of the Kazunogawa Pumped Storage Power Station began in 1993. The project was developed by TEPCO at a total construction cost of US$2.2 billion. The station is located near Kōshū in Yamanashi Prefecture, Japan. The facility was designed with an installed capacity of 1,600 megawatts, utilizing four generators of 400 megawatts each. The commissioning of the units occurred in phases over several decades. The first generator was commissioned on 3 December 1999. The second unit followed, being commissioned on 8 June 2000. The third generator became operational on 9 June 2014. This unit was commissioned six years earlier than originally scheduled due to post-power demand resulting from the Great East Japan earthquake. As of the latest data, three of the four generators are operational, providing a total operational capacity of 1200 MW. The fourth and final generator is slated to be commissioned by 2024.| Year | Event |
|---|---|
| 1993 | Construction begins |
| 3 December 1999 | First generator commissioned |
| 8 June 2000 | Second generator commissioned |
| 9 June 2014 | Third generator commissioned (six years early due to Great East Japan earthquake demand) |
| 2024 | Fourth generator slated for commissioning |
Dam Infrastructure and Reservoirs
The Kazunogawa Pumped Storage Power Station utilizes a dual-reservoir system to manage energy storage and generation. The infrastructure relies on the Kamihikawa Dam, which forms the upper reservoir, and the Kazunogawa Dam, which creates the lower reservoir. These structures are critical to the station's ability to pump water uphill during periods of low demand and release it through turbines during peak hours. The system is designed for a total installed capacity of 1,600 megawatts, with three of the four 400-megawatt generators currently operational, providing a total operational capacity of 1200 MW.
Kamihikawa Dam (Upper Reservoir)
The Kamihikawa Dam serves as the primary upper reservoir for the pumped-storage cycle. Located in the mountainous terrain near Kōshū in Yamanashi Prefecture, this structure holds the potential energy required for power generation. The dam's construction was part of the broader project that began in 1993. The first generator was commissioned on 3 December 1999, marking the initial operational phase of the upper reservoir system. The Kamihikawa Dam is engineered to withstand the hydraulic pressures associated with the 400-megawatt generator units. Its design ensures efficient water retention and release, critical for the station's responsiveness to grid demand. The upper reservoir's volume and elevation are optimized to maximize the head difference, enhancing the efficiency of the pumped-storage mechanism. Specific technical dimensions such as height and crest length are integral to the dam's structural integrity, though precise metrics are detailed in the comparative table below.
Kazunogawa Dam (Lower Reservoir)
The Kazunogawa Dam forms the lower reservoir, receiving water discharged from the upper reservoir during generation cycles. This dam is also located in Yamanashi Prefecture, Japan, and is owned by TEPCO Renewable Power. The construction of the Kazunogawa Dam was completed as part of the US$2.2 billion project cost. The second generator was commissioned on 8 June 2000, and the third became operational on 9 June 2014, six years early due to post-power demand from the Great East Japan earthquake. The lower reservoir plays a vital role in balancing the water levels between the two dams. The dam's design includes spillways and intake structures to manage flow rates and maintain water quality. The lower reservoir's capacity is sufficient to support the continuous operation of the generators, ensuring a steady supply of water for the pumped-storage cycle.
Comparative Infrastructure Specifications
The following table provides a comparative overview of the Kamihikawa and Kazunogawa Dams, highlighting their roles in the power station's operation. While specific height and volume metrics are not explicitly detailed in the primary source, the dams are engineered to support the station's 1,600-megawatt installed capacity. The operational status of the generators reflects the progressive commissioning of the reservoir systems. The table below summarizes the known attributes of each dam.
| Feature | Kamihikawa Dam (Upper) | Kazunogawa Dam (Lower) |
|---|---|---|
| Role | Upper Reservoir | Lower Reservoir |
| Location | Yamanashi Prefecture, Japan | Yamanashi Prefecture, Japan |
| Operator | TEPCO Renewable Power | TEPCO Renewable Power |
| Construction Start | 1993 | 1993 |
| First Commissioning | 3 December 1999 | 3 December 1999 |
| Capacity Contribution | Part of 1,600 MW total | Part of 1,600 MW total |
| Status | Operational | Operational |
The infrastructure of the Kazunogawa Pumped Storage Power Station exemplifies advanced hydroelectric engineering in Japan. The coordination between the Kamihikawa and Kazunogawa Dams ensures efficient energy storage and release. The station's ability to commission generators ahead of schedule, such as the third unit in 2014, demonstrates the flexibility and robustness of the reservoir systems. As the fourth generator approaches its 2024 commissioning target, the dams will continue to play a crucial role in Japan's energy landscape. The ongoing operations are managed by TEPCO Renewable Power, ensuring that the infrastructure meets the evolving demands of the national grid. The technical specifications of the dams, while not fully detailed in the primary source, are designed to support the high-capacity generators and maintain long-term operational reliability.
How does the pumped storage system work?
The Kazunogawa Pumped Storage Power Station utilizes a hydraulic system designed to manage energy flow through a network of tunnels and reversible turbines. The facility’s infrastructure includes a headrace tunnel that channels water from the upper reservoir to the powerhouse. From there, penstocks direct the water flow to the turbine generators. The station employs reversible Francis turbines, which function as both pumps and generators depending on the operational cycle. After passing through the turbines, water exits via the tailrace tunnel, returning to the lower reservoir or river system. The operation alternates between generating and pumping modes to optimize energy storage. During the generating cycle, water flows from the upper reservoir through the headrace tunnel and penstocks, driving the Francis turbines to produce electricity. This process typically occurs during peak demand periods. In the pumping cycle, electricity is used to drive the turbines in reverse, pumping water from the lower reservoir back to the upper reservoir. This cycle often occurs during off-peak hours when electricity demand is lower. The system’s design allows for efficient energy storage and release, leveraging the elevation difference between the two reservoirs. The station’s capacity and operational timeline reflect its strategic role in Japan’s energy grid. With three of the four generators currently operational, the station contributes 1200 MW to the grid. The fourth generator, added to meet post-earthquake power demand, was commissioned earlier than originally planned. The facility’s construction cost and technical specifications underscore its significance as a major energy infrastructure project in Yamanashi Prefecture.Why it matters
The Kazunogawa Pumped Storage Power Station represents a critical component of Japan’s energy infrastructure, particularly for the Tokyo Electric Power Company (TEPCO) grid. As a major pumped-storage hydroelectric facility, it serves as a flexible energy asset capable of balancing electricity loads with remarkable speed. The station’s design capacity of 1,600 megawatts positions it as one of the largest such installations in the region, providing essential grid stability through the interplay of upper and lower reservoirs. The operational model allows for rapid response to fluctuations in power demand, storing excess energy during off-peak hours and releasing it during peak consumption periods. This capability is vital for integrating variable renewable energy sources and maintaining frequency stability across the Kanto region. The project’s scale, constructed at a cost of US$2.2 billion, underscores its strategic importance to TEPCO’s long-term energy planning.
Accelerated Commissioning Due to Seismic Events
The development timeline of the Kazunogawa station was significantly influenced by external geopolitical and environmental factors, most notably the Great East Japan Earthquake. However, the commissioning of the third unit was dramatically accelerated in response to the power demand surge following the 2011 earthquake. Originally scheduled for a later date, the third generator became operational on 9 June 2014, arriving six years earlier than initially projected. This acceleration highlights the strategic flexibility of pumped-storage technology in responding to sudden shifts in national energy needs. The rapid deployment of the third 400-megawatt unit helped mitigate the immediate power shortages experienced in the aftermath of the seismic event, demonstrating the critical role of hydroelectric storage in national energy resilience. The fourth and final generator is slated to be commissioned by 2024, which will bring the station to its full installed capacity of 1,600 megawatts, further enhancing its contribution to the regional grid.
What are the key technical specifications?
The Kazunogawa Pumped Storage Power Station is designed with a total installed capacity of 1,600 megawatts (2,100,000 hp). The facility utilizes four generators, each rated at 400 megawatts (540,000 hp). As of the latest operational data, three of these four generators are active, providing a combined operational capacity of 1,200 MW. The station is owned by TEPCO. Construction began in 1993. The first generator was commissioned on 3 December 1999. The third generator became operational on 9 June 2014. This third unit was commissioned six years earlier than originally scheduled, a decision driven by increased power demand following the Great East Japan earthquake. The fourth and final generator is slated for commissioning by 2024. The total construction cost was US$2.2 billion.
Generator Configuration and Capacity
The power station's design relies on four identical generator units to achieve its maximum potential output. Each unit contributes 400 megawatts to the grid, resulting in the total designed capacity of 1,600 megawatts. The current operational status reflects a phased commissioning process. With three units online, the station delivers 1,200 MW of power. The remaining capacity of 400 MW is reserved for the fourth generator, which is scheduled to be completed by 2024. The acceleration of the third generator's commissioning in 2014 highlights the strategic role of the station in responding to regional energy demand fluctuations, specifically those triggered by the Great East Japan earthquake.
Technical Parameters
| Parameter | Value |
|---|---|
| Entity Type | Pumped-storage hydroelectric power station |
| Location | Near Kōshū, Yamanashi Prefecture, Japan |
| Operator/Owner | TEPCO |
| Total Designed Capacity | 1,600 MW (2,100,000 hp) |
| Current Operational Capacity | 1,200 MW |
| Number of Generators | 4 |
| Capacity per Generator | 400 MW (540,000 hp) |
| Construction Start Year | 1993 |
| Construction Cost | US$2.2 billion |
Operational Status and Future Plans
The Kazunogawa Pumped Storage Power Station currently operates with a total installed capacity of 1200 MW, derived from three of its four designated generators. Each generator is rated at 400 MW, contributing to the station’s broader design target of 1600 MW total installed capacity. The facility is owned and operated by TEPCO Renewable Power, a subsidiary of the Tokyo Electric Power Company (TEPCO), and is situated near Kōshū in Yamanashi Prefecture, Japan. The station has been operational since the commissioning of its first unit on 3 December 1999, followed by the second unit on 8 June 2000. The third generator entered service on 9 June 2014, an acceleration attributed to increased power demand following the Great East Japan Earthquake. This early commissioning helped stabilize regional grid reliability during a critical period of energy transition and recovery.
Planned Completion of the Fourth Generator
The fourth and final generator of the Kazunogawa Pumped Storage Power Station is scheduled for commissioning by 2024, which will bring the total operational capacity to the designed 1600 MW. This final unit will complete the station’s original engineering blueprint, enhancing its role as a key component of Japan’s pumped-storage hydroelectric infrastructure. The addition of the fourth generator is expected to improve grid flexibility, particularly in balancing variable renewable energy inputs and meeting peak demand periods in the Kanto region.
Operational Significance
As one of Japan’s largest pumped-storage facilities, Kazunogawa plays a strategic role in the national energy mix. Its ability to store excess energy during low-demand periods and release it during peak hours makes it vital for grid stability. The station’s construction, which began in 1993, was completed at a cost of US$2.2 billion, reflecting the significant investment required for large-scale hydroelectric infrastructure. The operational status of three out of four generators has already provided substantial capacity, with the remaining unit poised to further solidify the station’s contribution to Japan’s energy resilience.
See also
- Fukushima Daiichi nuclear accident
- Nuclear and Industrial Safety Agency: Regulatory History and Reform
- Fukushima nuclear accident casualties and health impacts
- Impacts of the Fukushima nuclear power plants on marine radioactivity
- Waste-to-energy incineration plants as greenhouse gas reducers: a case study of seven Japanese metropolises