Catching the Electric Vision

 

Sure enough, if you make the trek to Flam through nearly 50 tunnels in between the prominent towns of Bergen and Oslo, you will behold such a craft. The 40 meter Vision of the Fjords was recently constructed by Brødrene Aa shipyard in Norway and delivered to The Fjords AD earlier this year in June. The vessel is simply striking, with accessible ramps switch-backing up the sides of the superstructure, mimicking the mountain paths cut into the steep banks surrounding the fjords. The vessel provides ferry service between Flam and Gudvangen, but the journey truly offers one of the most remarkable tours through the Nærøyfjord, which is listed as a UNESCO World Heritage site.

 

CEO of The Fjords, Rolf A. Sandvik, has taken an aggressive approach in implementing new technology. Such a position has earned the company the prized honor of having its new vessel named Ship of the Year at the recent 2016 SMM commercial maritime expo in Hamburg, Germany. Sandvik is enthusiastic about embracing new technology, even with full anticipation and expectation that any cutting edge innovations implemented on the boat could become obsolete so quickly after being put into service. Sandvik, like many others recognize that the initial efforts made by their companies will spur on bystanders to join in and push the limitations of development to even greater bounds.

 

The Vision of the Fjords contains a unique hybrid system that employs the independent use of a full battery powered system in addition to a diesel powered controllable pitch propeller propulsion system. During part of voyage, the vessel will utilize twin MAN 1000 horsepower engines to cruise at a speed of 19 knots. The propulsion shaft is connected to a 150 kW Oswald electric motor-generator. When the vessel is transiting the eco-sensitive UNESCO heritage site, the captain can seamlessly shut down the diesel engines and run on pure electric battery power fed by two battery arrays run by ABB’s DC grid system.

 

For The Fjords, the return on investment is tangible with benefits coming both from capitalizing on low cost shore side hydroelectric power in lieu of more costly diesel and from the environmental gain achieved by operating completely carbon-neutral during half of the voyage. This vessel makes the case that ‘being green’ can generate ‘green’ as operating costs are lower and customers are positively drawn to the mission and technology of the new vessel and desire to experience it firsthand. Furthermore, the primary port of operation for the Vision of the Fjords has offered premium boarding locations and landing times for vessels that are equipped with clean emission technology, which gives The Fjords a platform to edge out the competition.

 

Retrofitting or implementing battery powered propulsion technology on a new construction vessel is not as simple as it may appear—the technology comes with some limitations and caveats. Battery power can be utilized in a variety of ways in marine applications, including peak shaving for both hotel load and propulsion power requirements. Batteries can also be installed as a hybrid arrangement as part of a diesel-electric propulsion system or they can be fit as a standalone power source to cleanly and quietly drive all propulsion and onboard power requirements. Applications similar to the Vision of the Fjords that can fully operate on battery power tend to be limited in speed to around 8 to 10 knots and have a range of approximately 1 hour of run time on full electric (battery) power on average.

 

Beyond the electrical components, the auxiliary support and safety systems must also be examined. 

 

Considering the limitations on battery run time, having proper shore side infrastructure for recharging is paramount. With ample shore side power available, charging times can be quick, reaching full recovery in as little as 10 to 20 minutes. Even with quick charging times, busy workboats will be bound by the down time of charging and this time must be minimized for any ROI to be recognized. In order to speed up the process, companies such as ABB are automating the charging procedure through the use of robotics and pantograph arms that will automatically latch hold and immediately begin the charging process as soon as the vessel is near enough at the dock.

 

Being able to accelerate the charging connection time by as little as 30 seconds can make a significant impact for a busy work boat that is charging frequently throughout the day. Ferry operator Norled, has successfully implemented a pantograph charging arm for their 80 meter car ferry, Ampere, which is 100 percent battery powered. ABB will soon be providing the first ever industrial robot to quickly handle all charge plug connections for HH ferries operating between Sweden and Denmark.

 

For many operators, a complete reliance upon battery powered propulsion just is not feasible, especially if routes are too long. Real estate and weight are also very real considerations. The Vision of the Fjords specifically chose to construct their vessel from carbon fiber sandwich technology, which offered a one-third savings in weight over aluminum and helped offset the heavy payload of the batteries. For some applications, in order to get adequate power, it may be necessary to fill nearly every void with batteries. Fortunately, the technology is constantly improving along with package size and power density ratios.

 

The batteries themselves are only a part of the many components required to make the system work. Rectifiers, DC to DC converters, battery management systems, the array control system, and back-up auxiliary power supply (APS) are all needed. Additionally, the circuit breaker switch gear that completes the power connection flow should not be overlooked and this component can sometimes mirror the size of an entire battery array. Lastly, most will want a layer of redundancy to provide back-up as a failsafe to get home to port. 

 

If batteries do indeed make sense for your application, there probably is a growing concern about fire and thermal runaway—especially with all the latest issues developing around mobile device batteries. Should thermal runaway take off from cell to cell in a battery array, the result can be catastrophic, generating enough heat to easily liquefy any metal boat they may be contained in. There are, however, many advances in air cooled and water cooled lithium battery technologies that provide the newest batteries with comprehensive battery management systems and safety features. These allow shutdown of the cells before trouble can begin. Classification society DNV-GL has also written guidelines for installing battery propulsion technology, including requirements for firefighting systems that do offer some measure of assurance for the operator.

 

Visiting the Vision of the Fjords is a clear testimony to the advances and reality of feasible electric propulsion powered by batteries. As Rolf Sandvik advocates, the technology will only get better and become viable for more and more applications. The cost premium for batteries is considerable and the life span varies, ranging from 2 to 10 years depending on the size and charging cycles. For The Fjords, the technology works and the capital investment is recouped on the backend savings in operating costs. With the vision of electric propulsion showing such favorable potential the vision may soon become a reality for many, offering a new and feasible propulsion alternative for modern work boats around the world.

 

 

 

(As published in the November 2016 edition of Marine News)