Interest among North American vessel owners in hybrid and electric propulsion continues to grow, driven by fuel-saving, emissions reductions and maintenance advantages
Rapid advancements in energy storage and the clear fuel-saving and emissions reduction benefits of marine hybrid and electric propulsion are generating strong interest among North American vessel owners. This interest is fuelling internal discussions about the advantages of incorporating these technologies into newbuilds and existing vessels. Inevitably, these discussions also examine some of the concerns, one of which is capex costs.
Those were some of the key takeaways at the Business Case for Hybrid and Electric Technology in North America webinar, part of Riviera Maritime Media’s Maritime Hybrid, Electric and Fuel Cells Webinar Week. The event was produced with the support of Navtek Naval Technologies and ABB.
Panellists included HMS Ferries Inc technical director Daniel Frank, ABB Marine and Ports technical solutions manager Peter Bryn, Navtek Naval Technologies general manager Ferhat Acuner and Glosten senior naval architect Will Moon.
“Upfront capital costs and more complex engineering remain stumbling blocks”
Mr Acuner highlighted Navtek’s success in developing the world’s first zero emissions, all-electric harbour tug, Gisas Power, which went into service in the shipyard zone in the Port of Istanbul earlier this year. Compared to a 30-tonne bollard pull diesel tug, Navtek estimates that Gisas Power – known as a Zeetug – cuts CO2 emissions by 210 tonnes and NOx emissions by nine tonnes annually.
Building on those environmental credentials, the Turkish naval architectural firm now has several zero-emission electric vessel projects underway, designing and building two additional Zeetugs, a garbage and sewage collection tanker and a surface collection vessel. Research and development is ongoing into other vessel types.
To maximise the efficiency of a Zeetug, Mr Acuner emphasised the need to adjust the technical requirements of the vessel based on the existing operational profile of a client. When creating that profile, the designer needs to ask: ‘How often do the tugs operate?’ ‘What are the power requirements for the vessel’s different operations?’ ‘What are the distances sailed?’ and ‘How long does each operation take?’ Once this profile is built, he said, the vessel could be customised to meet the owner’s needs.
Midlife upgrade to hybrid-electric
Agreeing with Mr Acuner, Mr Moon said a big driver of hybrid and electric propulsion is the significant reduction in operating costs. Mr Moon’s naval architectural firm, Seattle-based Glosten, is supporting the efforts of Washington State Ferries (WSF) in the conversion of the Jumbo Mark II ferries to electric power. The impetus behind the conversion of the Jumbo Mark II Class ferries is that WSF is the largest consumer of diesel fuel in the state of Washington, at some 18M gallons of diesel per year and the largest generator of greenhouse gas (GHG) emissions in state transportation (about 73% of annual GHG emissions).
The three Jumbo Mark II vessels consume about 26%, or some 5M gallons of diesel annually. WSF sees the three vessels as ideal conversions to hybrid-electric power as part of their midlife propulsion upgrade. As a result of the conversions, WSF expects to benefit from improved engine reliability and significant operating costs, while reducing its total carbon emissions by 25%.
“A big driver of hybrid and electric propulsion is the significant reduction in operating costs”
Mr Moon said using emission-reducing technologies such as hybrid and electric propulsion could also attract support from federal or state grants. For example, he said, a grant was available from California in support of zero-emissions projects. He also added that the quieter and lower vibration levels are attractive, particularly for excursion or research vessels.
Still, Mr Moon said upfront capital costs and more complex engineering remain stumbling blocks.
“You pay more upfront,” said Mr Bryn, “but you have a good payoff over the lifetime of the vessel.” The payoff comes in the form of significant lifecycle cost savings, said Mr Bryn. He made the point that lifecycle costs for electric powertrains are typically lower than conventional diesel-powered vessels. This is due to higher energy efficiency, lower maintenance and reduced fuel costs.
All-electric vessels also offer a path to zero emissions. ABB supported development of the first newbuild all-electric passenger vessel, Nikola Tesla, and its sister vessel, James V Glynn in the US. These Niagara Falls tourboats are each powered by a pair of battery packs with a total of 316 kWh, split between two catamaran hulls. This creates two independent power systems providing full redundancy.
The vessels will use shoreside charging between every trip while passengers disembark and board. Total charging time for each vessel is about seven minutes, allowing the batteries to power the electric propulsion motors capable of a total of 400 kW. This is controlled by ABB’s integrated Power and Energy Management System (PEMS), in order to optimise the energy use on board.
The other benefit of operating on battery power is that the electricity is clean, renewable hydropower generated by Niagara Falls itself.
Following US Coast Guard approval, both vessels are expected to enter service for American tour boat operator Maid of the Mist at Niagara Falls.
Mr Bryn said the capital costs for hybrid and electric vessels will fall as the industry moves away from bespoke solutions. He concluded: “It has to be the right fit for the owner and for the vessel.”
Mr Frank also believed strongly in the opex savings generated by operating an all-electric vessel, as compared to a diesel-geared vessel. Mr Frank’s company, HMS Ferries, operates the Gee’s Bend ferry, the first all-electric ferry in the US. Converted to all-electric propulsion in 2019, the vessel operates on a 1.45 nm route between Camden and Boykin, Alabama. Charging stations were established on both sides of the river.
Mr Frank pointed out that there was less maintenance over the lifetime of a lithium-ion battery than there is for a diesel over the same period. Maintenance costs were one of the drivers for the conversion of the vessel. Additionally, he said batteries were also much easier to access than diesel engines.
As for safety, the Gee’s Bend Ferry has two redundant battery rooms. In the case of a battery incident, a blower fan mounted on the deckhouse takes in fresh air to vacate any fumes in the dedicated plenum, but only after a designed waiting period, protecting crew and passengers.
Polls bear out high degree of interest
Polls taken during the webinar clearly showed the high degree of interest among delegates in fitting their vessels with hybrid or electric power. Some 52% of respondents said they were ‘very likely’ or ‘somewhat likely’ to repower or build a new hybrid or electric vessel in the next few years. And, in even more resounding fashion, 75% said that their organisation was currently discussing hybrid and electric propulsion.
Their enthusiasm, however, is tempered by several concerns, with 40% saying that capital costs were too high. Among the other concerns cited by respondents were unrealised operational cost savings (16%), system complexity and maintenance (16%), schedule and budget overruns (3%) and technical maturity of equipment (24%).