published on 10 January 2022 in energy

Ocean Battery, the idea of storing energy in the middle of the sea

Offshore renewables are becoming increasingly popular and play a key role in the energy transition. However, in order to function optimally, they require tailor-made storage solutions that can be integrated directly into off-shore systems or anchored to the seabed. Ocean Battery represents one such solution: designed by Ocean Grazer, a spin-off of the Dutch University of Groningen, the new ocean battery was presented a few days ago at CES 2022 in Las Vegas, one of the world’s most important events dedicated to technological innovation. And it immediately earned the prestigious CES Innovation Award.

Ocean Battery: Credits: oceangrazer.com

What does this new ocean battery consist of? Ocean Battery is a storage system designed specifically for marine power plants powered by waves, sun or wind. Its operation is inspired by that of pumped storage hydroelectric plants, which use water and gravity. The project involves building a concrete tank on the seabed containing up to 20 million litres of water stored at low pressure, to which a system of pumps and turbines is connected, as well as a flexible air bladder on top. The system envisages that electricity generated by the renewable energy systems associated with the battery be used to pump water from the reservoir into the bladder. The stored water is then released when needed driven by the pressure of the water column above the bladder itself. The transition from top to bottom is expected to drive the hydroelectric turbines producing electricity again.

According to the developers, the submarine battery has an efficiency of between 70 and 80% and an operational life of over 20 years, with an unlimited number of charge and discharge cycles. A single Ocean Battery is expected to have a capacity of 10 MWh, which can be expanded by the installation of multiple units according to final needs.

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