Submarine energy storage

Figure: Fraunhofer IWES

For the StEnSea concept, hollow concrete spheres are placed in deep water depths as energy storage unit

Figure: Fraunhofer IWES

The precast concrete sphere, which was tested in Lake Constance, has a diameter of 3 m

Figure: Fraunhofer IWES

Figure: Hochtief Solutions AG

Schematic presentation of the StEnSea concept

Figure: Hochtief Solutions AG

Figure: Hochtief Engineering GmbH

Casting of the concrete sphere

Figure: Hochtief Engineering GmbH

Figure: Fraunhofer IWES

Installation and testing the pump turbine on the concrete sphere

Figure: Fraunhofer IWES

The concrete sphere is lowered into Lake Constance

Figure: Fraunhofer IWES

The article is a preview of the yearbook “Beton Bauteile 2018” (ISBN 978-3-7625-3679-6), which will be available at www.profil-buchhandlung.de and at local German bookstores from 1 December 2017.

Increasing installation of fluctuating energy sources calls for development of suitable energy storage systems. In a research project, a new underwater pumped-storage power station is now being investigated and tested in Lake Constance.

The functional principle is similar to that of a conventional pumped-storage power station. An artificial cavity with an integrated pump turbine is installed in the seabed as the lowest reservoir, and the surrounding sea is the upper reservoir. The pressure difference between the lower and upper reservoirs corresponds to the head of a conventional pumped-storage power station and correlates with the depth of the water.

Figures 3 and 3a show a schematic presentation of an underwater storage unit, the artificial cavity of which is formed by a hollow concrete sphere.

When energy is required, a...