BaroMar selects Jacobs for energy storage pilot

BaroMar has selected Jacobs to develop the preliminary design for a first-of-its-kind underwater large-scale, long-duration energy storage pilot project off the coast of Cyprus.

Anna Stakhiv/AdobeStock

Utilising existing mature technology in power, energy, and marine engineering, combined with the hydrostatic pressure of the seawater, the system aims to achieve relatively low installation costs and the lowest levelized cost of storage (LCOS), with a goal of round-trip efficiency of up to 70 per cent.

The technology is claimed to address the challenges of relying on intermittent renewable sources and the capital costs of supporting infrastructure. 

“This project requires extensive geophysical, geotechnical and bathymetric surveying, investigation, feasibility studying and permitting for tank installation at deep depths for onshore mechanical and electrical equipment needs,” Jacobs vice president Fiachra Ó Cléirigh said in a statement.

The basis of the 4MWh pilot project relies on storing compressed air in large rigid tanks that are ballasted on the seabed. The tanks are designed to resist loads imposed by the marine environment as well as the compressed air and hydrostatic water pressure, during installation and operational conditions.  


When electricity production is in surplus a compressor increases ambient air pressure to the required level - typically 20 to 70 bar - at depths of 200m to 700m. The pressurised air is sent into large and rigid interconnected underwater reservoirs pushing out the water inside them.

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

BaroMar added that its patented solution has a typical thermodynamic efficiency of sixty per cent and installation costs as low as $80kW/h kilowatt hour.

The company added that low construction costs are achieved using traditional marine construction and installation methods, and a design that almost eliminates the need for underwater maintenance.

“BaroMar’s technology harnesses excess electricity from the grid and stores it safely below the sea’s surface, to be mobilised when needed. 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,” said Yonadav Buber, CEO of BaroMar, an Israeli energy storage start-up.