Updated at 12.20pm

Offshore wind farms, like most renewable energy plants, have been lauded as an efficient and green alternative to fossil fuel energy but lack of wind to provide power or electricity still cause headaches.

Three Maltese researchers have come up with an innovative idea that is gaining traction abroad: a device that is similar to a ‘battery pack’ that acts as an energy storage system in cases of emergency.

“The storage system is so innovative because renewable energy companies can generate electricity even when there is no sun or wind,” team leader Tonio Sant said. If there is less wind or sun, and energy is needed, this ‘battery’ can be used to keep the grid going, he added.

The project is dubbed FLASC: Floating Liquid Piston Accumulator Using Seawater Under Compression.

“It is also a play on words, since the equipment is basically like a water container,” engineer Daniel Buhagiar said.

The system has two pressure containers underwater that compress air. FLASC uses the compressed air for energy storage while maintaining a stable pressure.

The technology then converts the renewable energy supply into output.

Reliability is everything

“Think of it like a battery: the issue with renewables is the sun is not always shining and the wind is not always blowing. Most of the time, as consumers we expect a certain fixed output, so there is a need for this buffer,” Dr Buhagiar continued.

Renewable energy is intermittent and is consequently hard to predict.

 “We want to change that intermittency into a guaranteed power supply,” Dr Buhagiar said.

Engineering experts (left to right) Tonio Sant, Daniel Buhagiar and Robert Farrugia next to their ‘emergency battery’.

Many foreign wind turbine offshore farms have tried to solve the problem by turning to large-scale batteries. However, these can be fire hazards and are dangerous when used out at sea, Prof. Sant pointed out.

Oil and gas infrastructures are also looking for renewable energy to power their processes.

“An oil rig can demand 95MW of energy, a quarter of the power Malta demands,” Dr Buhagiar said.

“They look to wind turbines as an option to power their system but it is a process that runs every day and all the time, so reliability is everything.”

A prototype of the FLASC project is situated at Dock No. 1, in Cospicua.

The researchers from the Faculty of Engineering and Institute for Sustainable Energy at the University of Malta are now eyeing Northern European markets.

The project is supported by the Fusion R&I Technology Development Programme of the Malta Council for Science and Technology (Project R&I 2015-044-T), the Maritime Seed Fund of Malta Maritimma, the University Research, Innovation and Development Trust and industrial partner Medserv plc.

Maltese scientists have developed an innovative offshore energy storage system that was awarded a Statement of Feasibility by an independent certification body. The prototype of the structure is pictured here in Vittoriosa. Photos: Matthew Mirabelli