Hydrogen could be the key to unlocking the full potential of offshore wind in the North Sea, say advocates of power to gas technology
Hydrogen is the most abundant element in the universe, although on earth it is usually found in combination with oxygen in water and in other compounds. Once separated from the other elements it is an ideal energy carrier and the chemical element with the highest energy density. It can be produced from a range of compounds, including natural gas and biomass, or from water by electrolysis, using electricity.
Currently, most hydrogen is produced from natural gas, but it has been recognised for some time that producing it by electrolysis using renewable power is a potential way to store energy from intermittent sources, such as wind.
Using hydrogen in this way could also provide an alternative to batteries to store excess energy from wind. In many countries, electricity grids do not have the capacity to handle future demand. Hydrogen produced using renewable energy could provide a way around that. It could also be injected into existing gas grids, it is suggested, and could get around the need for a connection to the electricity grid where this is problematic. Hydrogen produced using renewable energy could also be used in transport and as a fuel for heating, either blended with natural gas or neat. It is widely used in the chemical industry and seems set to play a growing role in the economy as a whole.
Offshore wind energy is growing at a tremendous rate and taking off in many countries, reinforcing the potential opportunity to use electricity from offshore wind in so-called power to gas projects producing hydrogen. In fact, late 2017 saw the World Energy Council (WEC) release a report in which it claimed that hydrogen “could be the key to unlocking the full potential of the North Sea offshore wind industry.”
“Recently we have seen a great focus on offshore wind generation in the North Sea and capacity is rapidly increasing. However, various pathways to bring the power generated to the consumer efficiently are needed,” said the WEC. “This urgency is driven not only by the timelines set out by the Paris Agreement, but also by storage requirements and finding ways to enable the decarbonisation of industry and transportation.”
Its report, Bringing North Sea energy ashore efficiently, takes the rapidly increasing offshore wind capacity in the North Sea as a starting point. Coupled with demand on shore, it showed that a number of technologies were needed in order to bring energy to the consumer in the most efficient way.
The study looked at two pathways: an electrons (power) pathway, and the ‘molecules’ pathway, with a focus on hydrogen. The study concluded that a combination of both will be needed.
“Hydrogen from power to gas technology would be an important way to improve security of supply, while reducing CO2 emissions in sectors which would otherwise be difficult to decarbonise,” the WEC said. “If produced at a large enough scale, it could become an affordable alternative to fossil fuels.”
Numerous pilot projects in Europe have already demonstrated the ability to produce hydrogen using clean energy from onshore wind. Eoly, part of Colruyt Group in Belgium, Fluxys and offshore wind developer Parkwind recently started work on an industrial-scale power to gas project that will use offshore wind. Together, they plan to convert green electricity from offshore wind into hydrogen that can be transported and stored in Belgium’s natural gas infrastructure.
Unlike other demonstration projects elsewhere in Europe, Eoly, Parkwind and Fluxys are planning a commercial-scale project and aim to build a power to gas facility that can convert several megawatts of electricity from offshore wind into hydrogen which can be marketed as carbon-free fuel or feedstock. They also plan to use the project to demonstrate that production of hydrogen by power to gas can offset the variability of renewable energy production, such as from offshore wind.
Together, the partners in the project will explore the ability of power to gas to offset the variability of power from offshore wind and provide support services to the grid. Hydrogen produced in the project will be transported and stored in the existing natural gas infrastructure, reducing the use of natural gas as a source of energy for heating, transport and industry.
Interest in using green electricity from offshore wind has also been expressed elsewhere. The world’s leading offshore wind developer Ørsted is looking at a pilot project in Germany, and in the UK, the world’s largest offshore wind market, the Institution of Mechanical Engineers (IMechE) recently released a report that said the UK’s power system could become greener and more efficient if excess generation from renewable sources was used to create hydrogen to heat homes or power transport solutions, or be injected into the gas grid in low-hydrogen concentrations. The report further suggested that such a system of energy storage could be more efficient than other solutions, such as batteries.
Colruyt’s regulatory and public affairs advisor Jan Van Den Bulcke told OWJ the partners in the Belgian project plan to use it to test the technical and economic feasibility of power to gas using offshore wind. “We will be looking at whether there is a market for hydrogen produced in this way, focusing initially on potential users in the Port of Zeebrugge,” he explained. “In the longer term we are also looking at how hydrogen from offshore wind might provide grid services and, working with Elia, the transmission system operator (TSO), are examining the feasibility of grid connection.”
Hydrogen from offshore wind energy could one day play a role in providing services to TSOs, he suggested, including ancillary services, that is, services above and beyond generation and transmission, provided to a system operator to facilitate and support the continuous flow of electricity so that supply will continually meet demand. Assuming it successfully passes main ‘gate’ approvals in the next couple of years, construction of the Belgian project could get under way in the early 2020s.
In September 2017, the Dutch gas grid Gasunie operator joined the North Sea Wind Power Hub, a consortium that already included three electricity and gas grid operators: TenneT Netherlands, TenneT Germany and Energinet. Together they are exploring power to gas solutions that could be used on ‘power link’ islands built in the North Sea. The consortium’s plan is based on the fact that the volume of offshore wind energy required for the energy transition is so large that gas-based transmission and storage solutions will need to be deployed in addition to electrical connections.
They highlighted that the cost of storing and transmitting energy from offshore wind in the form of gas is “considerably lower per unit of energy than if the energy is transmitted and stored in the form of electricity.”
Gasunie will contribute its expertise in transporting and storing gas via interconnected international grids and managing the balance between the supply of and demand for energy. The company is also developing expertise in using renewable gases such as hydrogen, and is looking into various conversion processes, including producing hydrogen by power to gas.
“Conversion into hydrogen is expected to play an important role in the North Sea Wind Power Hub,” said the consortium. “It will enable wind-generated energy to be stored in the form of gas offshore, then brought ashore via existing offshore gas infrastructure.”
Experience from other power to gas projects undertaken in the UK and elsewhere also suggest that turning electrons into molecules could provide an efficient way to store and transmit energy from offshore wind.
ITM Power chief executive Graham Cooley said another important potential advantage of using hydrogen to store power from renewable energy was its ability to do so for long periods of time, much longer than is possible with batteries
In April 2018, Northern Gas Networks (NGN) hailed the results of a power to gas feasibility study as a “compelling step forward for the future of UK energy storage.” A collaborative desktop study, funded by the Department for Business, Energy and Industrial Strategy (BEIS) and led by Sheffield-based energy and clean fuel company ITM Power, used network planning models and data from the gas distributer for the north of England.
Speaking to OWJ in July, ITM Power chief executive Graham Cooley said another important potential advantage of using hydrogen to store power from renewable energy was its ability to do so for long periods of time, much longer than is possible with batteries. He said using hydrogen as a long-term energy carrier had “huge potential.”
Dr Cooley also highlighted the potential to use existing gas infrastructure in the North Sea and said his company had already held discussions with leading offshore wind developers. This echoed the findings of a study by the Energy Delta Institute (EDI). The EDI study found that the economics of offshore energy conversion, converting offshore wind energy into hydrogen on existing oil and gas platforms in the North Sea, was “economically promising.”
ITM Power and other companies active in the hydrogen industry have developed a range of electrolysers that could be used. ITM Power specialises in proton exchange membrane electrolysers, which Dr Cooley said were ideal for use with intermittent power supplies.
In the long term, he suggested, electrolysers could be integrated with new-generation multi-megawatt turbines to produce hydrogen offshore. The company’s HGas product brings together rapid response and self-pressurising PEM electrolysis into an integrated package capable of addressing MW-scale applications while accommodating fluctuating power profiles.
Dr Cooley rejected suggestions that electrolysers are currently too expensive, although electrolysis is seen as a much more expensive method of hydrogen production than other techniques such as steam methane reforming. Other sources suggest large-scale production of electrolysers would reduce costs to a point that power to gas would become economic.
A white paper produced by DNV GL on behalf of the European Power to Gas Platform, published in September 2017, concluded that power to gas could enable optimised infrastructure investments necessary to integrate large amounts of fluctuating renewables into the energy system. It said this could reduce the need to extend and upgrade the electricity network to transport large amounts of locally-produced energy to other locations, by using capacity in the existing gas networks. It reiterated Dr Cooley’s point that in the form of hydrogen “energy can be stored long-term.”
It also highlighted that hydrogen from renewable power to gas is a carbon-free fuel and feedstock that can support the decarbonisation of the transport sector and energy-intensive industries. It also noted that power to gas can help reduce the carbon intensity of the gas sector thereby ensuring its relevance for the future energy supply.
“From a technological perspective, power to gas is ready for commercial exploitation,” it concluded. “However, the challenge is to quickly reach an industrial scale that is economically exploitable. This depends heavily on the market conditions for the different applications. Significant cost reductions and efficiency improvements are required to enable its deployment on a commercial scale.”
In a May 2018 comment, International Energy Agency senior renewable energy analyst Cédric Philibert also highlighted offshore wind’s potential role in producing hydrogen via electrolysis.
He noted that apart from reducing carbon emissions compared with gas reforming hydrogen generation, power to gas from offshore wind could provide other benefits, including greater energy security, and lower price volatility. In addition, procuring clean hydrogen-rich chemicals and fuels from deploying renewables in areas with good wind resources, such as North Africa, could represent a welcome diversification of energy imports.
In this context, he said, Europe might follow a twin-track policy: first, accelerate deployment of offshore wind power and electrifying European industries, directly with efficient electric heating and process technologies, and indirectly through hydrogen production; and second, initiate conversations with neighbouring countries with wind resources (and potential investors) on renewable capacities, conversion plants and other infrastructure from which a trade in hydrogen-rich chemicals and fuels could develop, for the benefits of both exporting and importing countries.