New propulsion technology can help owners cut fuel consumption and emissions from a new generation of ships, according to experts at Riviera’s Alternative propulsion systems: the selection conundrum webinar
The event was held in partnership with Berg Propulsion as part of Riviera’s Marine Propulsion Webinar Week.
Berg Propulsion managing director Jonas Nyberg, Core-Power chief executive Mikal Bøe and Kongsberg Maritime vice president for the Kongsberg Hydrodynamic Research Centre, Göran Grunditz analysed various configurations and alternative approaches to ship propulsion driven by the need to save fuel, reduce emissions, minimise maintenance and provide operational flexibility.
Mr Nyberg admitted shipowners are faced with an almost bewildering array of options when it comes to selecting the most suitable propulsion solution for their vessels as “there is an abundance of propulsion configurations”.
With owners needing to get the most out of the vessel’s propulsion while meeting operational requirements and reducing emissions, he said they "need to match the power to the contractual requirements, such as towage vessels needing to meet certain bollard pull requirements”.
“But most of the time, tugs are not at this point. So how do you make sure your vessel configuration enables the lowest and leanest possible operating costs for this vessel?” Mr Nyberg asked.
One solution is to configure the whole propulsion, engine to propeller, as one system, he said.
“We are trying to get into this process as early as we can, and understand more about the operational profile and how this is going to be used with the contractual requirements.”
Mr Nyberg said designers, owners and shipyards should work in partnership with propulsion suppliers to configure a compromise that suits both contractual and environmental requirements “so that you get to the leanest vessel system that you can ever get to”.
Mr Grunditz agreed with this approach as a key method of reducing shipping emissions and shipowners’ fuel costs.
“There is a lot of knowledge in propulsion systems suppliers to reduce [owners’] carbon footprints,” he said. “By involving us in an early stage, we can achieve a lot of savings both to the fuel bill and the environment.
“This certainly comes by having the capability to both design and deliver the products we have in our portfolio.”
Kongsberg’s portfolio includes the new ELegance Pod, which is a rotatable electrical thruster with the motor installed directly on the propeller shaft.
Mr Bøe introduced the possibility of propelling ships using a new form of nuclear power. He unveiled the atomic battery that has a molten salt reactor and a power conversion system using sCO2 Brayton Cycle turbines.
“The idea is to have a liquid-fuel, molten-salt reactor operating at very high temperature, without high pressure,” Mr Bøe said. “Therefore, a meltdown or an explosion as a result of it is unthinkable.”
He suggested one atomic battery could power a ship for 25-30 years with no need for refuelling and that batteries in a modular configuration could produce 10-25 MW throughout a vessel’s lifecycle.
Mr Bøe said atomic batteries could be cost effective across the whole lifecycle of the ship, and that a prototype could be ready in 2024 followed by first installations in 2027-28.
“We could be running 25-30% below the cost of running on ultra low sulphur diesel,” he said.
Surveyed on issues including vessel lifetime costs, webinar attendees were asked to rank the importance on a scale from one to five, measuring the total lifecycle cost of a vessel on the environment. Some 62% of respondents said it was of absolute importance (level 5), and none said it held zero importance (level 1). Only 1% felt it merited a level 2 concern, 10% voted for 3 and 27% thought 4, meaning nearly 90% felt it a highly important issue.
Attendees were then asked where they felt they could make the biggest difference on vessel fuel consumption. The vast majority, 88%, voted for designing the equipment for the intended operational profile and the rest (12%) for selecting a more efficient engine.
In another poll, attendees were asked what makes most difference in reducing vessel fuel consumption. More than three quarters (77%) voted for operating the main engine and controlled pitch propeller in variable speed, while 23% said increasing engine efficiency by 5%.
There was almost a complete majority for the final poll. Attendees were asked whether they agreed with this statement: ’the choice of propeller diameter and optimisation makes a real difference to fuel consumption’. Almost all (97%) agreed this was very significant and just 3% voted for no, a propeller is a propeller.
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