Pumped Hydro Storage

Enabling the energy transition

Centralized synchronous plants will be less dominant in the future energy mix and with the massive penetration of intermittent renewables such as wind and solar and their impact on the grid reliability is huge. Supply of energy is variable and services to maintain voltage or frequency of the grid cannot be met by inverter-based resources.

Hydropower can play a defining role in the energy transition thanks to the balancing and system services to the grid that facilitate the integration of variable renewables.
With higher needs for storage and grid support services, Pumped Hydro Storage is the natural large-scale energy storage solution. It provides all services from reactive power support to frequency control, synchronous or virtual inertia and black-start capabilities. It brings support that was previously managed by fossil-fueled power plants but with even more reactivity and in a sustainable manner without CO_² emissions.

For years, Pumped Hydro Storage has offered a cost-effective way to provide reliable large-scale balancing and grid services. New pumped hydro storage technologies—such as variable speed capability—give plant owners even more flexibility by providing grid frequency support in both directions (in turbine and pump modes) as well as quicker response times.
The high inertia of rotating machines can also stabilize the grid in case of disturbances, which influences grid frequency, enabling low-inertia renewable energies, such as wind and solar to enter the grid and allowing their power to be transmitted over great distances.
Hydro storage technology is an enabler for the transition and modernization of 21st century power generation. It provides production, storage and grid stabilization. Moreover, it brings a critical benefit that distinguishes it from the others—water management.

How does Pumped Hydro Storage work?

Pumped hydro storage plants store energy using a system of two interconnected reservoirs with one at a higher elevation than the other. Water is pumped to the upper reservoir in times of surplus energy and, in times of excess demand, water from the upper reservoir is released, generating electricity as the water passes through reversible Francis turbines on its way to the lower reservoir. The process is then repeated with an overall cycle efficiency of about 80%.

With fixed speed pumped storage plants, power regulation is possible while the plant is generating electricity but with the state-of-the-art variable speed technology, power regulation in specific ranges is possible while generating and while pumping, providing additional flexibility to support the grid stability.

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• Large-scale: This is the attribute that best positions pumped hydro storage which is especially suited for long discharge durations for daily or even weekly energy storage applications.

• Cost-effectiveness: thanks to its lifetime and scale, pumped hydro storage brings among the lowest cost of storage that currently exist.

• Reactivity: the growing share of intermittent sources reduces the inertia of the grid, which increases its instability. Reactivity, then, is key to avoid incidents, and hydropower production and storage can provide inertia and load balancing services to the grid. The current technologies provide response times that are counted in seconds or even milliseconds in the case of variable speed technology.

• Mature technology: for decades, pumped hydro storage has offered a cost-effective way to provide large-scale balancing and grid services, with predictable cost and performance. New hydro storage technologies, such as variable speed, now give plant owners even more flexibility, output, efficiency, reliability and availability.

• Renewable and Sustainable:  Hydropower uses the force of water that can be pumped uphill and turbined downhill as much as needed. pumped hydro storage plants have a lifetime of more than 40 years for the electromechanical equipment and 100 years for the dam. Closed-loop pumped hydro storage present minimal environmental impact as they are not connected to existing river systems. In addition, they do not need to be located near an existing river and can therefore be located where needed to support the grid. 

• Multi-functional: water management, irrigation control for agriculture, water distribution and water waste control.

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GE’S TECHNOLOGY AND EXPERIENCE TO HELP YOU OPTIMIZE YOUR PROJECT

GE is a world leader in pumped storage plant equipment and supplies in-house capabilities not only for turbines and generators but also the full electrical balance of plant.

GE Renewable Energy offers integrated solutions for fixed speed pumped storage plants, as well as variable speed doubly or fully fed systems helping to minimize cost, maximize energy output and provide optimal grid support.

Vast experience, huge installed base

GE Renewable Energy has the largest installed base of hydropower storage units in operation. With more than 30% of the world’s hydro storage plants equipped with our technologies, we can provide a solution adapted to meet your specific needs in a variety of environments.
With a broad portfolio ranging from 30 MW to 400 MW per unit with heads up to 1,000 meters, GE Renewable Energy has a solution that will fit your specific site configuration. As one of the world leaders in this segment, we can supply not only pump-turbines and motor generators but also the full electrical Balance of Plant (BoP), including power converters, transformers, High-Voltage (HV) switchgears, synchronous condensers and circuit breakers for new greenfield plants as well as the installed base.

Higher flexibility and reactivity

Thanks to GE Renewable Energy’s know-how and R&D expertise, our engineers have pushed the boundaries of design with the latest generation of pump-turbines. These solutions combine high performance, high hydraulic stability, and low vibrations.
Furthermore, our innovative pump-turbines are not only flexible but also reactive: Less than 70 seconds are needed to switch from idle to full load for units up to 400 MW.

Innovative variable speed solutions for extra flexibility

GE Renewable Energy continues innovating with variable speed solutions that provide an extra-level of flexibility to the grid, delivering a more than 30% pumping power adjustment and a wider operating range.

Learn more about our hydro storage solutions by contacting us today.