FLASC: Revolutionizing Offshore Energy Storage and Hydrogen Production, an interview with Hydrogen Central.
In an era where renewable energy is paramount, FLASC emerges as a groundbreaking start-up addressing the critical issue of energy storage for offshore applications. Specializing in non-battery energy storage, FLASC aims to bridge the gap between the inconsistent supply of renewable energy and fluctuating consumer demand. Their innovative solution, tailored for co-location with offshore wind farms, employs an advanced hydro-pneumatic liquid piston concept. This technology stores energy by compressing air through liquid displacement, achieving high efficiencies by leveraging the marine environment as a natural heatsink. FLASC’s approach not only enhances the stability and cost-effectiveness of offshore energy storage but also optimizes hydrogen production, paving the way for a sustainable energy future.
FLASC is a start-up working on non-battery energy storage for offshore applications. It is tackling a fundamental problem: the mismatch between renewable energy supply and consumer demand. Renewable energy is not stable and predictable and neither is the demand. Integrating storage with renewables can be a solution to this problem.
It is the first solution tailored for co-location with offshore wind. It is based on an advanced hydro-pneumatic liquid piston concept where electricity is stored by pumping a liquid to compress a volume of air. Using a patented pre-charging concept, and the marine environment itself as a natural heatsink, the compression process is optimised to achieve very high efficiencies, resulting in an offshore solution that is cost-competitive with land-based storage
1. How does the FLASC system enhance the efficiency of hydrogen production through its energy storage capabilities?
FLASC has developed a complete hydrogen and Hydro-Pneumatic Energy Storage (HPES) system designs and bespoke modelling tools to evaluate performance of hydrogen production combined with intraday storage. Findings have been presented at leading conferences, and a patent has been submitted for this combined solution. Green hydrogen production relies on renewable power for electrolysis, and offshore green hydrogen production is seen as a natural match to offshore wind. Using intermittent power for hydrogen production has some challenges:
– Cost-effective offshore green hydrogen production requires infrastructure that operates consistently with high up time and minimal on/off cycling. Although potentially cheaper, Alkaline electrolysers have slower response times compared to Polymer Electrolyte Membrane (PEM) counterparts, making them more sensitive to variations in input power.
– Electrolyser on/off cycling impacts the capacity factor of the process and degrades the equipment, resulting in more frequent replacements. Alternatives are: (a) to undersize the electrolyser, resulting in higher utilization rate but surplus electricity that needs to be sold, posing a merchant risk and the need for a very expensive cable-to-shore connection; and (b) using marinized li-Ion batteries, at significant cost, high space requirements, safety concerns, and cycling degradation that adds OPEX.
FLASC effectively mitigates intermittency and optimises electrolyser utilisation, reducing on/off cycling. It enables the production of significant amounts of green hydrogen from offshore wind. By absorbing short-term intermittency and providing stable power to the electrolyser, FLASC lowers the unit cost of hydrogen. Pressurised seawater from the FLASC HPES system could also be fed into a desalination process and used as feedstock. It can also be used to store a buffer of desalinated water to be supplied directly to the electrolyser.
2. Can you elaborate on the effectiveness of the FLASC technology in terms of energy conversion efficiency? For example, if 100 MW of electricity is generated by wind power and stored using the FLASC system, what percentage of this energy can be stored? and converted into hydrogen? What efficiency levels has FLASC been able to achieve in practical applications?
A 70-75% high round-trip efficiency: without the additional cost and complexity of active thermal management systems implies that our end clients can extract 10-15% more value from each system. Achieving a high round trip efficiency is the main pain of the onshore CAES systems.
A scaled marine prototype of the FLASC HPES was tested in Malta from 2017 to 2019. The set-up stored energy generated from an array of PV panels and then released in a controlled manner, allowing for close monitoring of system performance and efficiency. Composed almost entirely from standard off-the-shelf components, the prototype is the ultimate proof-of-concept of the HPES technology. It was constructed in collaboration with industrial partner Medserv plc., thanks to financial support from the Malta Council for Science and Technology. The system was subjected to +400 of charging-discharging cycles and the cycle performance was deemed favorable achieving a high thermal efficiency consistently above 95% and a system availability of +98%. Key outcomes were published in the Journal of Energy Storage .
There are ongoing studies which are looking to evaluate the sizing of the FLASC system in the context of H2 production to then be able to assess of impact of the storage system efficiency on the overall efficiency of hydrogen production process. For example, the project “Hydro Pneumatic Energy Storage for Offshore Green Hydrogen Generation – HydroGenEration”, is looking into the application of this combined solution in a central Mediterranean context. The project is being led by FLASC co-founder Prof. Robert N. Farrugia, Associate Professor at the Institute for Sustainable Energy of the University of Malta. The project is financed by The Energy and Water Agency under Malta’s National Strategy for Research and Innovation in Energy and Water (2021–2030), Grant Agreement Reference: EWA 64/22.
3. What are the main advantages of using the FLASC system for hydrogen production compared to traditional methods?
In Green Hydrogen applications, co-located FLASC HPES can absorb short-term intermittency and deliver stable power to the electrolyser, resulting in a range of benefits:
– Increased hydrogen production for the same wind farm power rating.
– Improved electrolyser lifetime due to significant reduction in on/off cycling.
– Reduction in the overall unit cost of hydrogen produced (€/kg).
– These benefits increase in relatively lower wind climates (e.g., Mediterranean, Western Australia).
4. How does the use of the ocean as a natural heat sink in the FLASC system contribute to the stability and efficiency of hydrogen production?
Systems using compressed gas to store energy suffer from low thermal efficiency as the gas heats up during compression. FLASC HPES solves this by immersing the system in water which works as an excellent passive heatsink, absorbing heat during compression and restoring it during expansion. This results in high thermodynamic efficiencies (+95%) at quasi constant temperature without the need of complex thermal management systems, which means 10-15% more value per project for our clients.
5. What are the potential applications for the hydrogen produced using the FLASC-stabilized system, particularly in offshore environments?
Use of the FLASC system does not really change the quality of the produced hydrogen, so potential applications are the same as for typical green hydrogen consumers. For example, the offshore-produced green hydrogen can be exported onshore to direct hydrogen consumers or re-electrified. It can also be made available directly offshore for vessel re-fueling.
6. How does the integration of FLASC technology with hydrogen production align with global renewable energy and sustainability goals?
It is developing in line with the Dutch clean energy ambition to develop 70GW+ of offshore wind by 2050, which will require development of far-offshore sites. Transmission of wind energy from these remote sites could be made viable using hydrogen as an energy carrier. This will require off-grid production of hydrogen, which then benefits from co-located storage to enable more efficient and cost-effective operation of the hydrogen infrastructure.
7. As a finalist for the European Inventor Award 2024, what significance does this recognition hold for you, and how do you intend to utilize this to advance your objectives?
The nomination reflects the importance of energy storage for the European energy system and also helps to increase the visibility of the solution for its development acceleration and entering the market.
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FLASC: Revolutionizing Offshore Energy Storage and Hydrogen Production, an interview with Hydrogen Central.
