A majority of the attendees at Riviera’s Maritime Hybrid & Electric Conference said costs dictated the propulsion choices of their companies, but believed hybrid electric technology is well along its road to maturity
A straw poll held at the conclusion of Riviera’s Maritime Hybrid & Electric Conference in Bergen asked those in attendance about the priorities of the companies they represent. Specifically, it asked them where those companies rank profit-taking, investment in technology, and working to better the environment.
Sixty-one percent of those polled said their company’s main focus was profit. Of that 61%, some 38% said technology came second while only 23% said a greener world was priority number two.
Asked to respond to questions on a personal, rather than corporate, level, 30% of the audience said they would pay 5% more to use a "green" ferry while 29% said they would pay 10% more, meaning more than two-thirds would pay a premium for environmentally friendly technology.
Overall, a majority of the respondents saw a bright future for the maritime electric and hybrid industry with a majority believing it will reach fully maturity within a decade. And the conference’s final session, which focused on engineering considerations in hybrid and electric systems, echoed many of the outcomes from the poll.
Norwegian Maritime Authority project manager Kolbjørn Berge said his government has mandated a 40% reduction in shipping emissions by 2030, which he said was more ambitious than IMO goals in pushing industry for greener and cleaner energy and technology.
Mr Berge recalled that Norway pioneered LNG use between 2000 and 2010 and shared its experience with the international community to push for global regulations, ultimately resulting in formalisation of the IGF code. And he indicated Norway would play a similar role in battery technologies.
Corporate presentations, on the other hand, showed that even when given a government-led push on the environment is backed by public opinion, efficiency and profit often outweighed other considerations in a company’s technology choices. For instance, sales manager Rolf Petter Almli and naval architect Per Edvin Tande from Ulstein shipyard, where the world’s largest plug-in hybrid vessel Color Hybrid was built, said that Color Line considered a fully electric system for the ferry but ultimately selected a hybrid. Efficiency, profit and convenience were among factors that influenced the decision, they said. In the vessel’s diesel-mechanical propulsion mode, controllable pitch propellers offer flexible operations and ease of use. Furthermore, they said, during sea transits, a fully electric system can consume up to 6-8% more energy than a hybrid system.
Similarly, Color Line considered LNG, but decided against the technology based on space constraints. A hybrid system allowed Color Hybrid to afford the space for a large capacity battery of 5 MWh as well as an energy-saving heat reservoir of 10 MWh capacity that can be used to heat the vessel’s passenger accommodation spaces. Color Hybrid’s 5 MWh battery pack also provides 60 minutes of battery-only manoeuvring as well as covering sailing speeds from zero to 12 knots.
Following up, Wärtsilä Italia’s hybrid applications engineer Alessandro Mercante spoke about a hybrid system his company provided on a tug built for the port of Luleå. The port does not have particularly strict environmental regulations, but because the port is in a highly populated area, the owner chose to install the hybrid system to lower emissions and particulate matter.
With a battery capacity of 600 kWH, the tug can sail within the port or wait for a vessel’s arrival for up to 30 minutes on battery power alone. Battery-assisted engines mean that the engine can be brought up to 500 rpm after which the fuel is injected slowly. The process minimises emissions when compared to a conventional diesel engine, which is pulled up to 500 rpm with a mechanical start and aggressive fuel injection, leading to black smoke.
In light assist conditions, when the tug is bringing a vessel in to dock, the tug’s hybrid engines provide battery-powered peak shaving as the engine increases its rpms to push and pull the vessel. Mr Mercante said batteries help the vessel boost its bollard pull to 99 tonnes from the 87 tonnes provided by the diesel engines. He added the hybrid system ensures the engines run at an optimum, fuel efficient mode more often and put in fewer hours, which provides a maintenance and longevity benefit. He said simulation showed an expected 10% cut in fuel costs.