Construction is set to commence on an all-electric tanker and fuel-cell hybrid tankers are now a distinct possibility
It was always the case that the journey towards a low or zero carbon emissions tanker would require multiple stages. The preliminary steps took place a decade ago when Swedish company Tarbit Shipping initiated dual-fuel LNG power. Other Swedish companies who helped pioneer dual-fuel LNG power included Thun Tankers and members of the Gothia Alliance.
AET has also introduced dual-fuel LNG power on its shuttle tankers and intends to include VOC capture and liquification into fuel. Now a Japanese consortium has taken the next leap forward with the all-electric tanker. The seven members of the e5Consortium are: Asahi Tanker; Idemitsu Kosan; Exeno-Yamamizu Corporation; Mitsui O.S.K. Lines; Tokio Marine & Nichido Fire Insurance; Tokyo Electric Power Company; and Mitsubishi Corporation.
The consortium’s aim is to establish a platform that offers innovative ocean shipping infrastructure services based on electric vessels. In the first phase of the project, the consortium plans to launch the world’s first zero-emission electric tanker, powered by large-capacity lithium ion batteries, in March 2022.
The Group said that Japan’s coastal shipping sector faces structural issues, such as a shortage of mariners due to the aging of the seagoing workforce and aging vessels. Only Japanese crew are allowed to serve in the domestic fleet and the average crew age is close to 55 years old. According to local sources, there is a reluctance among Japanese youngsters to enter the domestic merchant marine sector.
“The consortium plans to launch the world’s first zero-emission electric tanker in March 2022”
In addition, the coastal shipping industry is under pressure to reduce greenhouse gas emissions (GHG) as Japan seeks to address climate change. The Group said its members are focusing on developing the potential of electric vessels to help address these problems.
The first e5 tanker design has been produced by e5 Laboratory Inc, and has the following specifications:
The design company e5 is also developing a hydrogen hybrid pure car carrier (PCC) in conjunction with MOL. The aim is to develop a deep-sea vessel which does not emit CO2, SOx, NOx or particulate matter in coastal waters or in ports. Propulsive force will be derived from electricity supplied by the hydrogen fuel-cell system and large-capacity batteries. In the open sea, the hydrogen hybrid PCC’s motor will be powered by an LNG-fuelled generator and large-capacity batteries, resulting in significantly lower emissions than current vessels equipped with diesel engines running on heavy oil.
But the key question remains: how do operators amortise their investments based on optimised performance and reduced operating costs? That was the question panellists were asked at a recent Riviera Maritime Media webinar, sponsored by Corvus Energy and Elliot Bay Design Group, titled The Business Case for Hybrid and Electric Technology.
Addressing the unique nature of the current energy transition, Elliott Bay Design chief electrical engineer Will Ayers explained: “This is not like sail to steam or steam to diesel; there’s no single clear-cut solution for this transition.” He pointed out that one of the exceptional issues at play involved the diversity of vessels and the operating profiles likely to be impacted, which effectively ruled out a one-solution-fits-all approach.
“When we are speaking about a hybrid electric system, there is an obvious challenge,” said Mr Ayers. “We have a lithium-ion rack – 124 kilowatt hours – and a three-gallon jug of diesel, 124 kilowatt hours. So, we’re still talking about this 50 to 1 energy density differential.” The first movers to hybrid vessels have been those on fixed, relatively short routes such as ferries in Scandinavia. Mr Ayers noting: “Short-haul vessels are the low-hanging fruit; this is where hybrid electric really has some distinct advantages.”
Taking up the subject of electric vessels, Cecilie Larsen, project manager, renewable energy, of the e-ferry for Aero Kommune in Denmark noted that despite the high upfront costs, the business case for electric vessels is fundamentally solid. “Battery prices are dropping rapidly,” she said. “We conducted a pre-study before the e-ferry project where we predicted battery prices would fall, but we hadn’t predicted they would drop at this rate. That is really good news for investment, since the battery pack is still a large part of the extra cost of an e-ferry.”
She also noted potential benefits from the avoidance of any future CO2 taxes and the ongoing value of second-life usage of the batteries, saying: “The break-even period can be even shorter when [these are] calculated in.”
The short-sea tanker operator with a limited number of port calls might find some optimism in the results from the e-ferry. Ms Larsen explained the break-even for the E-ferry prototype compared to a modern diesel alternative is within five to eight years. “Take into account that a lot of resources have been invested in R&D, design, communication and administration of the project, that will not apply for the next electric ferry in the series. Therefore, the break-even period for the next in line is expected to be within four years of operation,” she said. Ms Larsen went on to highlight that in the course of the Ellen e-ferry project, an equivalent battery pack had dropped 50% in price, adding “when we come to replace our battery pack, the price will be a quarter of the original cost.”
There are other savings, too. Fewer moving parts require less maintenance in the machinery space resulting in lower servicing and repair costs. Still, the initial outlay for a battery-powered vessel is high, compared to a traditionally powered ship, and Jon Diller, commercial director, Spear Power Systems explained why this was the case, but also why it was likely to change over coming years. “The major markets for lithium-ion batteries are automotive and large-scale energy storage systems for stationary applications, such as at power plants,” he said. “While marine is growing rapidly, it is unlikely to grow to become a significant percentage of the consumption of lithium-ion. For that reason, the attendant costs associated with a maritime lithium-ion battery are significantly higher.”
“When we come to replace our battery pack, the price will be a quarter of the original cost”
But, he said, if the energy content of a cell can be increased, then the number of modules and number of streams necessary to reach a certain capacity can be reduced. “Then the attendant costs associated with those peripheral items will reduce in kind and the overall system price will be lower.”
He predicted that over the next 10 years, solid-state cells would become widely available and commercially sustainable. “Then we will have a radical increase in energy density and a significant increase in inherent safety,” he said.
With the e5 all-electric tanker already in an advanced stage of development and fuel cell and battery technology increasing rapidly while the costs decrease, the shift toward a lower carbon, or even a net zero carbon emission, tanker is getting closer.