Propulsion expert sees promise in energy storage and green hydrogen

Recognition is also growing that energy storage systems based on batteries have a significant role to play in vessels working in the offshore wind sector.

These and many other issues will be discussed in OWJ’s Offshore Wind Webinar Week, which includes a webinar dedicated to reducing the environmental impact of offshore wind ships. ’Green vessels for a green industry: the offshore wind sector’s race to decarbonise its assets’ takes place on 10 June 2020, 09.00-09.45 BST.

Asked what he sees as the most promising avenues for the decarbonisation of vessels serving the offshore wind industry, one of the speakers taking part in the webinar, ABB global product and portfolio manager John Olav Lindtjørn, said he believes that energy storage technology and fuel cells, which use hydrogen, are among the most promising avenues for decarbonisation, not least because the energy that is needed could one day be produced in an offshore windfarm.

“A transition to a zero-emissions vessel can be achieved in a stepped approach where you start with a diesel-electric power system and add more batteries and fuel cells as the cost of these come down and infrastructure and supply matures,” he told OWJ.

Mr Lindtjørn said the operational profile of offshore wind ships such as service operation vessels (SOVs) and crew transfer vessels lends itself well to the application of solutions such as energy storage systems.

He suggested it might one day be possible for SOVs to charge their batteries or even bunker with clean fuel like hydrogen while offshore. Vessels working on windfarms close to shore could easily recharge their batteries from the shore, he said. “For windfarms further from shore, fixed bunkering points could help facilitate early adoption of clean fuels such as hydrogen for a fuel cell-powered vessel.

“For smaller vessels operating on batteries, the most important challenge would be to have cost-efficient charging infrastructure. As the cost of batteries declines and as their energy density improves, the business case for batteries will become more attractive, especially where operational profiles require more onboard energy storage,” Mr Lindtjørn told OWJ.

Mr Lindtjørn said he believes there are multiple reasons why owners active in the offshore wind industry are looking at emissions-reducing technology. “Energy storage and variable speed generators have good business cases,” he said, “be it from a direct reduction in fuel consumption or engine maintenance or indirectly through increased vessel attractiveness to a potential charterer.

“When charterers become active proponents of solutions such as these, they are elevated from a cost/benefit consideration to a licence to operate consideration. Going forward, we anticipate that the environmental footprint of vessels will be counted in the overall footprint of a windfarm and that this will further increase the focus on vessel emissions.”

Asked about the potential of shore-to-ship power, Mr Lindtjørn said, “There are solutions that are available already, but to go from where we are today to wider adoption the cost needs to come down.

“One important element of this is standardisation of shore-connection infrastructure and interfaces to facilitate inter-operability. Work on this has been ongoing for some time, but there is still a lot to do.

“Standardisation would reduce costs in a number of ways. Charging points offshore or close to a windfarm could extend the reach of battery-powered vessels, but the variable conditions at sea could sometimes present challenges with respect to transferring power to a vessel.”

Asked about the availability of green fuels such as hydrogen or methanol, Mr Lindtjørn said that for renewable fuel to be widely available, renewable energy – such as from wind – is needed to produce hydrogen to use in fuel cells or as a feedstock for other renewable fuels such as methanol or ammonia.

“Wind can be an energy source for renewable hydrogen, so it makes sense to have production facilities for green hydrogen close to where the energy is produced,” Mr Lindtjørn concluded.

Riviera is hosting a week of free to attend 45-minute webinars focused on offshore wind commencing 8 June. Register your interest now