A start-up from the University of Malta is developing a floating energy storage system that uses pressurised seawater and compressed air, and can be integrated directly into a platform of a floating renewable energy device such as a floating wind turbine.
The start-up deployed a scaled prototype of the Floating Liquid-piston Accumulator using Seawater under Compression (FLASC) in the Maltese Grand Harbour in the fourth quarter of 2017 to gather key performance data, while the installation itself served to demonstrate the efficiency of a novel method for tension leg platform (TLP) deployment.
The prototype, comprising a small-scale TLP with a gravity anchor, stores energy generated from an array of PV panels and discharges it in a controlled manner, allowing close monitoring of the performance and efficiency of the device. The scaled device has been made almost entirely from standard off-the-shelf components.
The FLASC system matches the lifetime of contemporary wind turbines and is cost-competitive with li-ion batteries, with the added advantage of not relying on hazardous chemicals and avoiding high recycling costs, according to the FLASC team.
Along with floating wind, potential applications include solar PV and wave and tidal energy systems, as well as liquefaction of natural gas, water injection in oil wells and water desalination.
The prototype deployment in Grand Harbour is funded by the Malta Council for Science and Technology (MCST) with technical and logistical support from an oil & gas logistics company Medserv.