Offshore wind provides clean energy for millions and is going global, but all of the vessels that work in the sector use fossil fuels. In recognition of that fact, vessel owners, designers and equipment providers are racing to develop new, greener propulsion solutions for offshore wind ships
Participants in OWJ’s upcoming webinar, Green vessels for a green industry: the offshore wind sector’s race to decarbonise its assets, which takes place 10 June 2020, 09.00-09.45 BST, will hear from a number of experts about the options available to develop green ships for a green industry.
Among them is DNV GL business/segment director special ships Arnstein Eknes, who set the scene for the webinar in a recent interview.
Asked what he believes to be the most promising avenues for decarbonising vessels serving the offshore wind industry, Mr Eknes told OWJ, “The first step should be to embrace energy saving where possible. We know that hybridisation will work with vessels that have large variations in power demand and battery uptake on new projects demonstrates this clearly.
“For some segments of the market fully-electric service vessels will be feasible, assuming the charging infrastructure is available. Alternatively, low or zero-carbon fuels such as hydrogen, in the form of ammonia or liquid organic hydrogen carriers (LOHCs), are the most likely the next step for this industry.”
Asked what is driving the growing interest in reducing emissions from crew transfer vessels (CTVs) and service operation vessels (SOVs), and whether the drivers are purely economic, Mr Eknes said canny owners are seeking a combination of energy efficient solutions that can reduce the cost of operations and reduce emissions.
“To operate in an energy-efficient manner reduces costs, and charterers are seeking low or zero-emission supply chains,” he said. An obvious example of the kind of industry leaders driving developments such as these is Ørsted, which recently unveiled an ambition plan to become carbon neutral, along with its supply chain.
Mr Eknes also highlighted shore-to-ship power as a potential decarbonisation avenue. “The technology is available today,” he said, “but from a commercial point of view it is very important to have a holistic view on who should invest in order for this to work and trigger the undoubted benefits.
“Power demand for large vessels can be significant and a proper understanding of charging philosophy and pricing is required for it to become attractive. Also, the initial cost for first movers will be higher before more standardised solutions are available, providing scale effect on price.”
Asked about the operational profile of offshore wind ships such as SOVs and CTVs and whether they make it easier or harder than other vessel types to reduce emissions, Mr Eknes said, “Their operating profile should make it easier to reduce emissions than it is for many other vessel types.
“In particular when a lot of time is spent at a windfarm waiting or close to wind turbines. In transit, operations are similar to those of a platform supply vessel in the oil and gas industry, where battery installations also have been used to reduce fuel consumption significantly.”
Asked about the challenges to overcome in more widespread use of batteries on small vessels, Mr Eknes said, “Small vessels are light, so their core energy storage medium would normally be another type of fuel which is light and contains more energy than a battery might. For low speed operation, over limited periods of time, and for transient modes of operation, such as lifting operations, a battery system would be ideal.”
As highlighted previously by OWJ, the availability of new types of fuel could be a challenge, at least for the time being. “Availability of any alternative fuel such as hydrogen or methanol will of course be limited until someone decides to move first,” Mr Eknes said.
“It would make sense for windfarm owners to consider the potential benefits of producing zero-emissions fuels such as hydrogen (or hydrogen carrying fuels) when there is excess production from wind.
“This would essentially be ‘power for free’ and would reduce the need to purchase conventional fuels, reduce costs and reduce emissions.
“We need to understand the business case better to see where this might work, in order to enable capacity and availability to grow and support the use of new types of fuel. A combination of offshore and land-based buyers for new fuels working together could make a difference because you wouldn’t only be dependent on demand from the marine sector.”
Riviera will host a week of free to attend 45-minute webinars focused on offshore wind commencing 8 June. Register your interest now