Subsea Pumped Hydroelectric Energy Storage

Meeting Global Carbon Emission Goals with Long-Duration Energy Storage

To achieve global net-zero emissions by 2050, it’s estimated that 70% of electricity generation must come from renewable energy. However, generation from wind and solar doesn’t always align with grid demands. To ensure grid resiliency and meet fluctuating periods of peak electric demand, there is a critical need for Long-Duration Energy Storage (LDES).

Pumped Storage Hydropower is currently the dominant form of LDES. But new deployments face hurdles, such as permitting issues, geographic limitations, and high costs. These barriers hinder the expansion of pumped storage hydro and underscore the need for innovative solutions to support decarbonization.

Introducing Sperra Subsea Pumped Hydro Storage

Sperra Subsea Pumped Hydroelectric Energy Storage is a groundbreaking solution that will expand the buildout of offshore wind and solar integrated with near-shore energy storage. Our solution offers all the benefits of conventional pumped storage hydro while sidestepping many of the siting and development constraints that hamper its expansion on land.

How does it work?

Subsea Pumped Hydroelectric Energy Storage operates by moving water in and out of large concrete spheres on the ocean floor to store and release energy as needed. It can be set up independently along coastlines or alongside offshore wind plants for cost savings and additional revenue opportunities. 

This approach facilitates cost-effective subsea LDES through innovations such as our patented multi-sphere “pod” design, localized manufacturing using automated 3D concrete printing, and integration with offshore renewable energy plants to share infrastructure and reduce costs.

large dock

Sperra subsea energy storage systems are designed to be manufactured in 2 MW to 5 MW modules in US ports using locally available materials and labor.

Key Advantages of Sperra Subsea Pumped Hydro Storage

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Increased grid resiliency

The technology will create new offshore energy storage sites close to large population centers, facilitating grid integration and resiliency.

Improved project economics

Integrated with offshore wind and solar, Sperra MPH reduces the need for energy curtailment, driving additional project revenues.

energy storage

Lower cost manufacturing

Sperra lowers the cost of manufacturing by replacing the labor-intensive process of conventional concrete construction (e.g., formwork assembly, casting, formwork removal) with an automated, lean manufacturing line using 3D printing.

Domestic manufacturing and local jobs

The technology will create local jobs through domestic manufacturing and relies on abundant, regionally available materials for construction (concrete, steel and copper).

testing equipment
MPH array

Environmental conservation

Sperra subsea storage minimizes land use and is resilient to sea-level rise, fires, floods, freezing, droughts and terrorism.

The Department of Energy, the National Renewable Energy Laboratory and the National Offshore Wind R&D Consortium have all identified developing and integrating efficient energy storage with offshore wind as a key facet to achieving long-term renewable energy targets. The challenge is to develop and domestically manufacture energy storage technologies to meet all US market demands by 2030. 

Work with us to accelerate the market for long-duration storage in ocean environments.

MPH array

Did you know?

Sperra (formerly RCAM Technologies) was named the Storage Innovations Champion in the US Department of Energy’s Energy Storage Innovations Prize. 

USA market map factoid

The US is the largest market for marine-pumped hydroelectric storage with over 7.5 terawatts and 75 TWh of net technical  potential in the Atlantic, Pacific and Gulf of Mexico, which is more than two times the US closed-loop pumped storage hydropower technical potential onshore (3.5 TW and 3,500 TWh).

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