PE Live: Hydrogen storage to boost offshore wind
The ability to store and transport energy as hydrogen means that far more locations in the North Sea and elsewhere become viable for wind generation
The development of offshore hydrogen production could hold the key to a substantial expansion of power generation in the North Sea while providing greater stability for power prices, panellists agreed on a recent PE Live webcast.
The amount of electricity that can be generated by offshore turbines in the North Sea would reach a natural limit while using deployed technology. Many of the sites that see high levels of wind, have short transmission distances to the coast and are located in shallow water have already been taken. And, in the absence of viable storage, increasing the number of turbines could lead to greater levels of downtime.
“A lot of offshore wind is already installed in the North Sea, but the potential is huge and cannot be fully utilised,” says Aurelie Nasse, strategic marketing director at MHI Vestas Offshore Wind. “The more offshore wind we put in the North Sea… the value of the extra electricity we produce goes down.”
She calls this the 'cannibalisation effect', the only available solution for which is to curtail production, basically stopping the turbine from producing electricity when there is enough to meet demand. “Today, already, 5pc of the wind energy is curtailed internally,” she says.
The other main problem associated with expanding offshore wind is that the further the turbine is from land the greater the electricity connection costs become.
“A lot of offshore wind is already installed in the North Sea, but the potential is huge and cannot be fully utilised” Nasse, MHI Vestas
Hydrogen is a “really good way of mitigating those offshore challenges”, she says. “Hydrogen could unlock some of the challenges offshore wind is seeing today.”
Firstly, hydrogen can be stored. “When there is a lot of wind in the winter in the North Sea, we can produce hydrogen that can then be put in seasonal storage, either to be later used as hydrogen in processes or to be put into the grid as electricity, through fired turbines or fuel cells.”
Secondly, transporting hydrogen over long distances can be up to ten times less expensive than transporting electricity, according to Nasse.
Offshore turbines in the North Sea are paired with offshore substations, which transfer electricity to the shore. This electricity could be used in electrolysers onshore—which would ease the price volatility and curtailment problems but would not help with the cost of transportation. If the electrolyser was also built offshore at the turbine site, with the hydrogen piped onshore, it would ease both problems.
“Hydrogen is good for wind but offshore wind is also good for hydrogen,” she says. “It helps the greening of hydrogen production and is a reliable technology for the strong potential of the North Sea.”
Building facilities to create hydrogen offshore would certainly require the development of engineering solutions, but the fundamental technology is already firmly in place.
“The great news is that producing, storing and utilising hydrogen all encompasses proven technologies that have been around for much of the past century,” says Michael Ducker, vice president, renewable fuels and western region, at manufacturer Mitsubishi Hitachi Power Systems.
“What is different today as we look at the technical and engineering problems is, ultimately, the use cases that each of these systems are being applied to, not fundamental differences in the core technology… We are optimising the designs for unique use cases.”
He notes that electrolysis has been around since the 1930s, serving the maritime and later space industries. Storing hydrogen at vast scale in salt caverns has been done since the early 1980s to serve the petrochemicals industry. And utilising hydrogen in gas turbines dates back to the 1970s.
“As the offshore wind market matures, we would certainly expect to see optimisations within those designs in how we apply them for offshore wind,” says Ducker. “But, overall, the good news is that the base technologies that we would be using are proven and have been around for quite some time.”
"The great news is that producing, storing and utilising hydrogen all encompasses proven technologies that have been around for much of the past century" Ducker, Mitsubishi
The emergence of green hydrogen storage is likely to provide a large boost to the wind and solar energy industry. “Green hydrogen has to be powered by renewables, so we need more renewables capacity,” says Sean McLoughlin, Emea head of industrials research, global research, HSBC, noting that the European Hydrogen Strategy, announced in July, targets 40GW of electrolyser capacity by 2030 and this would need 80-120GW of renewable power.
“An awful lot of new renewables is needed,” he says. “There is a question mark around whether some existing renewables would effectively be diverted towards powering hydrogen generation rather than being included in the power system, particularly if those renewables are curtailed or not monetising as expected. But certainly, it looks as though there will be a lot more renewables.”
While mass production of green hydrogen is likely to first become established in Europe, similarly suitable conditions exist in many other locations around the world.
“Offshore wind is really a North Sea industry that is globalising,” he says. “Taiwan has some of the best wind conditions offshore anywhere in the world, so that would be a great place with very, very high load factors for hydrogen generation.”
He adds that the US northeast region also has the scope for dedicated hydrogen generation and that, in Europe, other areas are emerging such as the Baltic and the Atlantic.
A recording of PE Live 9: Creating a sustainable hydrogen supply chain can be heard here.