⊗

With a rapidly growing number of battery hybrid ships and recent emerging tanker and e-bunker vessel concepts, the topic of batteries as a fuel source for shipping has been making a lot of headlines lately. Future prices of alternative green fuels may be a multiple of those of fossil fuels, while their availability will continue to be low for some time. Energy-saving technologies such as wind propulsion, hull air lubrication and batteries are seen as potential requirements to address the challenge and the International Maritime Organization’s Carbon Intensity Indicator targets. Ships fitted with battery setups have already surpassed the 1,000 mark, according to class society DNV and the Maritime Battery Forum, which show over 750 existing units and nearly 240 newbuilds sporting this green option. Splash Extra’s decision to explore this technology in depth this month was, in large part, spurred by a recent comment by Geir Bjørkeli, CEO of maritime battery maker Corvus Energy, who said: "Batteries cannot take us all the way. If you want to sail zero-emission, you will need to bring clean energy in a different format." What he means by that, Bjørkeli tells Splash Extra, is that batteries become "somewhat impractical" in terms of volume, weight, and price for longer distances. "While the technology exists to fully electrify any ship, it would require a significant amount of space, add substantial weight, and be costly for shipowners," he admits. Despite the promising numbers, electric hybrid or pure electric propulsion is still in its infancy when it comes to shipping, with cost, safety, and fast charging of batteries remaining big hurdles to overcome. For charging batteries with shore power and sailing parts or whole distances on charged shore power, the energy density becomes a showstopper for 100% decarbonisation for most of shipping, according to Eirik Ovrum, principal consultant at class society DNV. "The cost of batteries remains a large part of the cost of energy delivered for charged energy from shore if the batteries are only charged and discharged over a period of several days, as the cost has to be divided by the energy delivered by them over the lifetime of the batteries. So the more frequently the batteries are charged, the less the capex of the batteries will play a part in the overall energy cost," he explains. Sweden's SeaFjord Energy believes it has found a solution with an e-bunker vessel that delivers electricity to ships in port or at sea. "SeaFjord Energy´s solution reduces shipowners need to invest in extensively large battery packs and eliminates the requirement for complex onshore infrastructure to deliver electric power to ships. The solution enables energy to be delivered precisely where it is needed to optimise ship operations, thereby reducing operational costs,” Elias Magnusson, chief operating officer at SeaFjord Energy, tells Splash Extra. Class societies have carried out several studies on batteries and their use in the transport industry and expect their share in the maritime sector to be significant, with particular prominence in niche submarkets. However, this represents a small portion of the total shipping demand. Density issues The key requirement for larger ships, typically travelling further, is the density of the energy source, which must be sufficient to propel their large weight over long voyages without refuelling. One particular study by DNV found that batteries are not considered feasible technology for long distance shipping, as the energy density of batteries today and in the future is likely to remain too low. Syb ten Cate Hoedemaker, managing director of the Maritime Battery Forum, acknowledges that, indeed, most ships in the world are "very difficult or even impossible" to be powered by batteries alone, but he maintains that large battery systems will play a role for all types of ships in the future. "We believe that everything that can be done with batteries, should be done with batteries due to their higher energy efficiency compared to all alternative fuels," he says, foreseeing a future with battery systems on all ships, but only as part of the solution in most cases. For him, the future will also be in the further development and understanding of hybrid propulsion systems and he sees batteries as an enabler for other zero emission technologies. "Fuels like hydrogen, methanol and ammonia will be more expensive and have a lower energy density compared to diesel. So whatever fuel you choose, you want to consume as little as possible to be able to use your ship the way you want,” he says, adding: “Batteries are always a part of systems with fuel cells to handle the peak power demands, so they are complementary technologies and not competitors." Corvus Energy's Bjorkeli also admits that when it comes to longer distances, alternative technologies like hydrogen, ammonia, or e-methanol are needed, but that batteries will still play a crucial role in a hybrid combination by assisting in peak shaving, load levelling, and providing spinning reserve. "The significant advantage of utilising batteries is that nearly all the clean energy used to charge them will directly power the vessel without any emissions. In contrast, with hydrogen and ammonia, additional steps are required to produce the fuel using clean energy before it can be utilised to power a vessel. Hence, batteries make the most practical sense as long as a sweet spot is found between weight, volume, and cost, while also ensuring the ability to charge them at least once per day," he says. DNV's Ovrum maintains that it is clear that present day battery technology does not have a high enough energy density to take us all the way for short- and deepsea shipping, but he reminds readers that the history of battery electrification so far, both on land and at sea, has been one of gradually moving towards areas and segments where sceptics did not expect them to be used. "We can expect a gradual increase in the use of batteries, as the shore power infrastructure is expanded, batteries fall in price and have higher quality, and operators of ships figure out solutions for partial electrification that can work for their ship in an economical way,” he says. Julien Boulland, global market leader for sustainable shipping at Bureau Veritas Marine & Offshore, agrees with Bjørkeli that batteries will be a key part of the energy mix that will help shipping achieve its decarbonisation ambitions, observing an exponential growth in demand. He, however, notes that this doesn’t mean that batteries cannot play an important role for larger vessels, with different energy sources coming together on the same ship used in complement to conventional fuel-powered generators, providing power while in port, or potentially supporting the hotel load of cruiseships, for example. The French class society is supporting industry pioneers to ensure the safety of battery systems that are getting bigger in terms of power output. "We must keep in mind that batteries pose their own challenges in terms of safety, notably to prevent the risk of thermal runaway and fires," Boulland says, but warns that as demand accelerates and the use of batteries in shipping expands, challenges may also emerge with the availability of resources, to ensure that supplies of raw materials can keep up with demand. News from Japan came in at the end of May about how manufacturers are plotting electricity-carrying ships to ferry power from offshore wind farms without the use of subsea cables - betting that as the energy density of battery designs increases, they will be able to add a maritime side to their present land-side market, as batteries become a more credible alternative to undersea cables, and at progressively greater ranges. Madadh MacLaine, secretary-general of the Zero Emissions Ship Technology Association, reckons batteries are leading the charge in driving the industry’s transition to zero emissions shipping, with hydrogen close behind. For her, increasing power density, offshore and mobile charging, far offshore renewable energy generation and hydrogen production, breakthroughs in wind propulsion technology are all combining to create the perfect storm for zero-emission transoceanic shipping. "Batteries, having the greatest energy density of any energy storage system, and the ability to be recharged from renewable sources while underway, play a crucial role in combining hydrogen fuel cells and wind propulsion, enabling absolute zero emissions at all scales," says MacLaine.

How far can batteries take us?

Marine battery breakthroughs have been making headlines of late. They remain somewhat short, however, of powering deepsea trades today.

⊗

To continue reading, please login below or subscribe here.

Read Next

Owners advised to cash in

Measuring shipping hubs

April 2024 Review

The on/off risk premium for tankers

Curse of the dry cargo optimist

Owners advised to cash in

Measuring shipping hubs

April 2024 Review

The on/off risk premium for tankers

Curse of the dry cargo optimist

Maritime CEO Forum Singapore

Maritime CEO Forum Monaco

Advertising

Press Releases

Splash

Splash Extra

Splash Special Reports