Continuous green hydrogen from tidal power will be produced as part of a new flow battery installation at Scotland’s European Marine Energy Centre in Orkney.
Claimed to be a world first, the project will see Invinity Energy Systems delivering a 1.8MWh vanadium flow battery (VFB) at EMEC’s tidal energy test site on the island of Eday. VFBs can store and discharge industrial levels of power over multiple daily cycles and have a lifespan of 25 years, with little degradation. The pilot project will aim to demonstrate that VFBs can act as a bridge between the natural variations of tidal power and the consistent energy requirements of hydrogen electrolysis.
“This is the first time that a flow battery will have been coupled with tidal energy and hydrogen production, and will support the development of the innovative energy storage solution being developed in the Interreg NWE ITEG project,” said Neil Kermode, managing director at EMEC.
“Following a technical review looking at how to improve the efficiencies of the electrolyser, we assessed that flow batteries would be the best fit for the energy system. As flow batteries store electrical charge in a liquid rather than a solid, they can provide industrial quantities of power for a sustained period, can deeply discharge without damaging itself, as well as stand fully charged for extended periods without losing charge. These are all necessary qualities to integrate battery technology with the renewable power generation and hydrogen production process.”
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Invinity’s battery system consists of two separate tanks of vanadium electrolyte with different charges, both of which are connected to a central fuel cell stack. Electrolyte from the tanks is pumped through the fuel cell stack, where an ion exchange occurs across a membrane. When this exchange occurs, a reversible electrochemical reaction takes place, allowing electrical energy to be stored and subsequently discharged.
The technology relies on the ability of vanadium to exist in four different oxidation states (V2+, V3+, V4+ and V5+), each of which holds a different electrical charge. As the same element – albeit in different states – is used for both the positive and negative sides of the battery, many of the contamination and degradation problems that can occur in other batteries over time can be avoided.
“Vanadium flow batteries are the perfect partner for tidal power, continually absorbing then dispatching four or more hours of continuous power, multiple times per day, over decades of service – a duty cycle that would rapidly degrade lithium batteries,” said Matt Harper, chief commercial officer at Invinity.
“Because of their inherent variability, all renewable energy sources – including wind, solar and tidal – have difficulty providing the consistent power that industrial processes like electrolysis need to operate most effectively. Including energy storage in a comprehensive renewables-to-hydrogen system bridges that gap, providing a path to accelerated commercialisation of future green hydrogen projects.”
Funded by the Scottish Government via Highlands and Islands Enterprise (HIE), the modular flow battery will consist of eight Invinity VS3 battery units linked together into a single system. It will be assembled at Invinity’s manufacturing facility in Bathgate, West Lothian and is expected to go live at EMEC next year.
Do you have a technical paper describing the process for an engineer coming to this new
This is wonderful news, and could be a winner in the race to obtain renewable electric energy reliability and 24 hour supply. Please keep posted and advancements.
This is a great development and proves that Scottish engineering and innovation is alive and well. I hope that this work is commercially protected through patents. Watch out for attemps at theft via hacking attempts or acquisition and removal of the assets.. happens a lot!
“All renewable energy sources have difficulty providing the consistent power that industrial processes like electrolysis need to operate effectively.” That is simply NOT true. Geothermal and hydroelectricity are both ‘baseload’ AND flexible. (PHES capacity also delivers GWh.)
“Energy storage in a comprehensive renewables-to-hydrogen system bridges that gap, providing a path to accelerated commercialisation of future green hydrogen projects.” In actual fact, batteries are just ELECTRICITY storage, which is wholly inadequate, unaffordable and short-lived.
Before-Generator Energy Storage is better at bridging “that gap”. It is barmy to generate electricity under, on or above the sea. Expanding variable installations is a fool’s errand, so STOP adding all these little (10MW or less) generators. Harvest all these inexhaustible energies mechanically, so that you generate electricity flexibly/on demand FROM stored energy. Then you’d have no more intermittency, NO round-trip losses and NO constraint, BSUoS or Capacity Market charges. This all currently adds £5/MWh to wholesale prices.
Variable RE can NEVER be cost-effectively integrated with the existing ‘market’ network structure. Wind/wave AND tidal must have vertical integration, as ONE industry, in order to minimise storage CapEx AND operations costs.
“The project received £1.8m of funding from the Scottish Government.”
We cannot provide support to a specific project.” 12 Sept. 2019 – The Energy and Climate Change Directorate. Energy Industries Division. Scottish Government. Nobody will give you an honest or logical reason for demanding ‘match’ funding. Political ideology destroys British IP rights.
“It is appropriate that the risk of how the (electricity) storage asset is used over time is allocated to the grid system operator. (National Grid or SPEN) Their influence on the storage system (directly or indirectly) is greater.” But no company will ‘risk’ taking responsibility for the comprehensive, holistic ENERGY storage system we NEED – to run RE with minimal waste, at the lowest price. Governments have to shoulder the responsibility for building this essential infrastructure.
“Tidal generation is predictable – two high and two low tides each day. This is an extremely heavy cycling application, requiring up to four cycles per day, compared to solar coupled energy storage projects which typically require just one charge and discharge each day.” It can only make sense to couple PV generation with electricity storage. BGES (air/water accumulator) is immune to daily cycles, it has a service life measured in centuries and a whole-system potential commensurate with total installed capacity. This short-sighted project is no answer to the storage problem.
“This far-sighted project demonstrates how Invinity’s vanadium flow batteries can accelerate the commercialisation of producing hydrogen from renewable energy. Robust energy storage can ensure hydrogen production systems operate at their best, even when powered by intermittent renewable sources.” Batteries are NOT “robust energy storage”. All electricity storage, including PHES, is commercially unviable (It’s not been built!) and batteries are by far the worst option.
“As flow batteries store electrical charge in a liquid rather than a solid, they can provide industrial quantities of power for a sustained period, can deeply discharge without damage, and stand fully charged for extended periods without losing charge.” So what? 1.8MWh is a joke! At what price?
Harnessing ocean currents to generate green electricity is an opportunity that is being missed for significant Government support, when it has a big advantage over wind power because ocean currents are more consistent than wind that varies a lot from day to day. Maygen is also installing 6 ocean current turbines in this area but they are mounted on the ocean floor.
Why can’t hydrogen electrolysis be operated intermittently (alongside H2 gas ‘buffer’ storage) to match the variable tidal power, rather than storing electricity to maintain constant hydrogen production? I’d imagine an electrolysis cell would be broadly similar in cost to the redox flow cell and the extra cost for more electrolysers running ‘part time’ would be offset by eliminating the electricity storage requirement … ?
As noted by David Dundas, we seem to be almost ignoring the opportunity that having the second highest tidal range in the world gives the UK. Could this be that hidden under the sea our politicians can’t point to them easily and say “look what we are doing?”.
I’m all for tidal electricity generation but using it to make H2 (hydrogen) to then store the hydrogen for turning back into electricity again is utterly insane as the required infrastructure is *horrendously* expensive and only about 30% efficient. Quite why we are even talking about the utter idiocy of using wildly experimental H2-for-storage rather than just buying off the shelf battery technology (at more like 90% efficiency) is a complete mystery. But might it have something to do with the fact that ~98% of H2, currently manufactured, is derived from natural gas (Big Oil sticking its greedy snout in the trough again!)?