Statement of feasibility for new offshore energy storage technology

Technology assessment of FLASC concept next step towards development

University of Malta, FLASC

We forecast a 9-fold growth in grid connected wind power generation globally from 2,000 TWh in 2022 to 18,300 TWh by 2050 this means that grid electricity from wind will rise from 7% today to 30% in 2050 (source DNV's Energy Transition Outlook). As electricity consumption accelerates, bottom fixed and floating offshore windfarms will play an increasingly important role to ensure that the society can meet this demand. 

To optimize the match between supply and demand of electricity from offshore wind farms, the University of Malta has developed a new energy storage concept named FLASC (Floating Liquid Piston Accumulator using Seawater under Compression) that integrates compressed air energy storage (CAES) into a floating offshore wind turbine (FOWT) structures. Integrating large scale energy storage with offshore renewables is an opportunity to further investigate.

After developing a 1/10 scale demonstration prototype powered by a solar PV system, the University of Malta was looking for an independent 3rd party to assist them in a technology and commercial feasibility assessment of their FLASC concept. Such a study would allow the University of Malta to acquire a Statement of Feasibility for the FLASC concept, that can pave the way for them to attract interested parties to partner in their continuous efforts to further develop the FLASC concept.

DNV was asked by the University of Malta to perform this study, due to the unique attributes and qualifications that constitute DNV particularly capable of delivering the scope, such as:

  • Independence, integrity and quality, as the renewable industry’s trusted third-party advisor, DNV will assess the benefits and risks to renewable technologies neutrally, based on clear and transparent criteria and rigorous review of the evidence.
  • Independent advisory expertise and state-of-the art testing capabilities that constitute DNV uniquely qualified to help customers address the challenges and opportunities within the field of energy storage – today and in the future. The DNV GRIDSTOR recommended practice for grid-connected energy storage and the DNV marine battery standard DNV-RU-SHIP-pt6Ch2, which is accelerating safe and sound implementation of energy storage systems combined, are examples of our commitment.
  • over 30 years of wind, 85 years of offshore oil & gas experience and extensive technical understanding of floating wind, captured in the DNV design standard for floating turbines DNV-ST-0119.


The University of Malta has requested DNV to perform an independent high-level study of the FLASC concept, that consists of the following tasks:. 

  1. Technology Assessment, resulting in a Statement of Feasibility 
  2. Market assessment 
  3. Cost assessment 
  4. Competitors assessment 
  5. Barriers assessment 

Flasc handover statement of feasibilityThe project was successfully completed, resulting in a Statement of Feasibility for the FLASC (Floating Liquid-piston Accumulator using Seawater under Compression), as the technology has been assessed with basis in DNV-RP-A203 /1/ for its designated use. DNV considers the technology feasible as defined in /3/ and therefore suited for further development and qualification.

Value to the customer
With the Statement of Feasibility in place, the University of Malta is now in search for interested parties to partner & collaborate in their continuous effort to further develop the FLASC concept.