Offshore wind will play a central role in the production of green hydrogen and in the decarbonisation of heavy industry if industry leaders along the value chain work together
MHI Vestas global power and utilities lead analyst Aurélie Nasse told the WindTV conference that green hydrogen produced using renewable electricity from offshore wind is an ideal way to decarbonise hard-to-abate sectors, not least because of its scale.
It also has many other potential applications in transport and other sectors, and – potentially – offshore bunkering for ships using green hydrogen rather than carbon-based fuels, but partnerships are needed to build value chains and to reduce the cost of green hydrogen in a way that mirrors cost reduction in offshore wind in recent years.
If partnerships are created, Ms Nasse suggested, and if there is sufficient support from governments and the European Union, the cost of green hydrogen from offshore wind could fall steeply, potentially to less than €2.0/kg (US$2.40) by the mid-2030s, making it cost-competitive with carbon-based alternatives.
“We need to build value chains,” Ms Nasse explained. “We need to understand the demand side, and establish who needs green hydrogen, and how much they need. We need to establish what the cost impact of switching steel production to green hydrogen might be or how much green hydrogen a rail network might need.
“To help decarbonise sectors such as steel, GW-scale production of green hydrogen is required,” she told the conference, noting that this level of demand fits well with the growing size of offshore windfarms.
It also fits well with offshore windfarms’ increasing distance from shore – the further offshore windfarms are from the shore the greater transmission costs are. In contrast, bringing energy from offshore wind ashore as hydrogen would be much less expensive. Bringing energy ashore in the form of hydrogen, through pipelines, would be “ten times less expensive” than bringing it ashore as electrons over export cables that are hundreds of kilometres long, Ms Nasse said.
And offshore wind can also benefit from being used to produce green hydrogen in other ways, Ms Nasse explained. Renewable hydrogen could be used to store energy from offshore wind and reduce the potential effect of too much wind in the system, which could lead to price cannibalisation.
Another potential synergy between offshore wind and green hydrogen is that heavy industries such as steel-making and refining are to be found in coastal areas, so there is a geographical reason for converting wind power into green hydrogen.
If demand for green hydrogen is there, Ms Nasse said, the question for the offshore wind industry is not just can it be produced offshore, and how to transport it ashore, but where green hydrogen would actually be produced.
Should the electrolysers that split water into green hydrogen and oxygen be shore-based, or should they be offshore? And if offshore, should they be in individual turbines or on an offshore platform akin to a substation that would use electricity to produce green hydrogen from banks of electrolysers arranged in series?
Large-scale production of green hydrogen could also require changes to the design of offshore wind turbines, Ms Nasse indicated, noting that MHI Vestas is addressing issues such as these.
“On a typical turbine, AC electricity is converted to DC, then back to AC to step up the voltage,” she said. “The voltage is stepped up again on a substation before being transmitted ashore. Each step in that process results in losses and requires components and capital expenditure. In contrast, using electricity to produce green hydrogen could result in reduced losses, fewer components and reduced capital expenditure.
“But a turbine dedicated to the production of green hydrogen would be isolated from the grid, and that is not the way turbines are designed to work at the moment,” she explained. “A new type of turbine might be needed that could work in a decentralised way.”
As highlighted previously by OWJ, pilot projects are underway that are examining many of these challenges, but there are others to overcome too. Desalination equipment would need to be installed offshore, to provide the pure water electrolysers need, and electrolysers would need to be marinised to work in the offshore environment. Electrolysers would also need to be capable of handling intermittent generation from turbines.
Asked about the concept of energy islands producing green hydrogen from offshore wind, Ms Nasse said, “Should a turbine on an energy island be dedicated to producing electricity, or green hydrogen, or both?" noting that the cost of a hybrid turbine producing both could be higher than a conventional unit.
Asked about support mechanisms that could enable offshore wind to green hydrogen to become a reality, Ms Nasse highlighted the steep fall in the cost of energy from offshore wind in recent years, a process that will yield further cost reduction in future. “Offshore wind costs are still going down. With scale, the cost of electrolysers will come down too. What is needed is volume and greater efficiency,” she said, noting that in July 2020, the European Commission proposed building 6 GW of renewable hydrogen electrolyser capacity by 2025. It also proposed a target of 40 GW by 2030 as part of its hydrogen strategy.
“It is very encouraging to see the EU commit funds in this way,” Ms Nasse concluded. With bigger projects, with work in the value chain, greater efficiency and collaboration, large-scale production of green hydrogen from offshore wind, at a price that is competitive is achievable, she suggests.
In November 2020, Europe’s leading renewable energy organisations launched a coalition – the Renewable Hydrogen Coalition – to position Europe as the world leader in renewable hydrogen.
In September 2020, Green Hydrogen Systems (GHS) in Denmark confirmed it has been selected to work with Siemens Gamesa Renewable Energy to test the feasibility of large-scale production of green hydrogen from offshore wind.
Developing a domestic green hydrogen industry could generate £320Bn (US$422Bn) for the UK economy and sustain up to 120,000 jobs by 2050 according to a report from the Offshore Wind Industry Council and the Offshore Renewable Energy Catapult. The report, Offshore Wind and Hydrogen: Solving the Integration Challenge, examines the potential for hydrogen to play a key role in providing the flexibility, and short and long-term energy balancing required for integrating high percentages of offshore wind into the UK energy system and achieving net-zero climate change targets.
Ørsted and its partners in the Westküste 100 project recently received funding confirmation from the German Federal Ministry of Economic Affairs and Energy.
Eight industry-leading companies, SolarPower Europe and WindEurope recently launched ‘Choose Renewable Hydrogen,’ a joint initiative highlighting the role of renewables to ensure a sound economic recovery, aligned with the European Green Deal.
A Dutch project in the North Sea is to see green hydrogen produced on an offshore oil and gas platform using electricity from offshore wind.
UK-based ITM Power is working with leading wind energy developer Ørsted on a project to examine the feasibility of installing an electrolyser in the tower of an offshore wind turbine.