Large-Scale, Long-Duration Energy Storage
Engineered for the most demanding environments
From Offshore to Onshore Applications
Why Storage Matters
Renewable power is not always available when and where it is needed
Energy storage bridges the gap between variable generation and electricity demand.
When
Temporal Mismatch
Wind and solar generation vary over time and do not always coincide with electricity demand.
WHERE
Grid Mismatch
Network constraints can prevent renewable power from reaching users, causing curtailment and lost value.
Long-duration energy storage absorbs surplus power and delivers it when the energy system needs it.
How FLASC stores energy
A simple look at how renewable power is converted, stored underwater and delivered when needed.
2-MINUTE EXPLAINER
01
Charge
Renewable electricity drives the liquid-piston system to compress air.
02
STORE
Energy is retained as compressed air in submerged steel storage.
03
Deliver
The process reverses to return dispatchable electricity to the grid.
70%
Round-Trip Efficiency
4-100 Hours
Storage Duration
30 Years
Design LiFE
PROVEN ONSHORE
Qualification in Rotterdam
Our current onshore pilot allows FLASC to validate system performance, grid integration and operation under real-world conditions before scaling towards larger commercial and offshore applications.
125 kW
Grid-Connected Onshore Pilot
Lower cost, independently validated
Working across the energy value chain
Selected organisations FLASC has worked alongside through collaborative projects, technical studies and industry consortia.
“FLASC’s solution is an innovative technology with significant potential, offering a competitive and more sustainable alternative to Li-ion battery farms. The collaboration with FLASC will allow us to leverage Subsea 7’s world-class technical expertise in the development of offshore subsea solutions to accelerate the deployment of utility scale, low maintenance, storage solutions.”
Thomas Sunde
VP Strategy & Technology, Subsea7
Statement of Feasibility
Award Winning Innovation
Patented Technology
Lower cost, independently validated
2030 Levelised Cost of Storage (LCOS)[1]
(as Energy Storage)
[1] Grid Energy Storage Technology Cost and Performance Assessment, US Dept. of Energy: +100MW / 10-hr duration.
“FLASC’s solution is an innovative technology with significant potential, offering a competitive and more sustainable alternative to Li-ion battery farms. The collaboration with FLASC will allow us to leverage Subsea 7’s world-class technical expertise in the development of offshore subsea solutions to accelerate the deployment of utility scale, low maintenance, storage solutions.”
Thomas Sunde
VP Strategy & Technology, Subsea7
Statement of Feasibility
Award Winning Innovation
Patented Technology
A stronger business case for renewable energy
FLASC helps renewable assets manage volatility, increase delivered power value and accelerate clean-energy deployment.
Video Credit: TKI Offshore Energy
Manage market volatility and merchant risk
Renewable energy is increasingly exposed to market volatility and merchant risk, weakening the overall business case.
Increase the value of renewable power
FLASC adds flexibility to the energy supply, hedging volatility and increasing the value of delivered power.
Strengthen project economics and deployment
Improving the business case of wind and solar enables more projects to be built and accelerates clean-energy deployment.
10–30%
More revenue for offshore wind farms
5–7 years
Typical payback with a 30-year design life
Grid Balancing
Enabling renewables to provide flexibility services
Offshore Co-Location: Batteries & Beyond for Net Zero
An independent study exploring the future of offshore co-location, examining how integrating energy storage with offshore wind can enhance system flexibility, reduce curtailment and unlock new commercial value.
This paper has been prepared by Xodus, a Subsea7 company (April, 2026)
The Open-Gas Cycle technology embodies the latest developments in performance and energy density
“FLASC’s solution is an innovative technology with significant potential, offering a competitive and more sustainable alternative to Li-ion battery farms. The collaboration with FLASC will allow us to leverage Subsea 7’s world-class technical expertise in the development of offshore subsea solutions to accelerate the deployment of utility scale, low maintenance, storage solutions.”
Statement of
Feasibility
Award-Winning
Innovation
Patented
Technology
Our technology at work
featured projects
Award-winning solution recognised for its global impact:
FLASC is grateful for the financial support received from:
