Jacobs chosen to design underwater energy storage pilot

TECHNOLOGY developer BaroMar has appointed Jacobs to develop the preliminary design for its large-scale, underwater, long-duration energy storage pilot project, situated off the coast of Cyprus.

Yonadav Buber, CEO of BaroMar, said: “As the world graduates from fossil fuels for its primary energy supply to renewables, there is an equal imperative to deliver cost-effective and low-impact storage solutions.”

BaroMar is developing compressed air energy storage (CAES), which stores energy in the form of pressurised air. It says while the technology is cost effective for bulk energy storage, it is uncommon due to geological and regulatory development constraints. Curtis VanWalleghem, CEO of CAES technology company Hydrostor, explained to TCE last year that CAES plants typically rely on uncommonly located salt caverns for air storage.

Instead, BaroMar’s technology – the basis of the 4 MWh Jacobs-designed pilot – relies on storing compressed air in large, rigid tanks that are ballasted on the seabed.

Fiachra Ó Cléirigh, general manager of energy and power at Jacobs, noted that the project will require extensive surveying, investigation, feasibility study, and permitting related to the underwater tank installation.

Underwater energy storage

Using BaroMar’s energy storage technology, when electricity production is in surplus a compressor increases ambient air pressure to the level required. The pressurised air is then piped into large and rigid interconnected underwater reservoirs for storage, pushing out water. These tanks are designed to resist loads imposed by the marine environment as well as the compressed air and hydrostatic water pressure during both installation and operation.

When demand for electricity rises and the stored energy is required, the compressed air is released back through the pipe, driving water back into the reservoirs. Meanwhile, the air flows through a thermal recovery system into a turbo expander that drives a generator to supply the grid.

Buber said: “With its low capital requirements and minimal maintenance, this is a sustainable, environmentally friendly and scalable solution that will reinforce net zero ambitions, while offering the world secure supply in times of energy crisis or unpredictability.”