battery powered

Electrifying the Ferry Market

The first all-electric ferry built for operations in the United States may soon be coming to fruition in the Pacific Northwest. Bremerton, WA-based Art Anderson Associates with partner EESImarine has been developing concepts for the first all-electric battery-powered vehicle ferry to be produced and used in the United States. This zero emissions ferry will be the first of its kind putting the United States and more specifically, the Puget Sound region, on the map as a leader in green technology in the marine industry.

Art Anderson Associates is at the forefront of green technology within the marine community. Founded in 1957 as a naval architecture and marine engineering firm, the company has grown and diversified to employ architects, naval architects, planners, construction managers and civil, structural, mechanical and electrical engineers to create an interdisciplinary team. Art Anderson Associates has supported local and international ferry systems including Washington State Ferries and Alaska Marine Highway Systems for over 30 years.

New ferry for Guemes Island route
Art Anderson Associates and EESImarine are teaming up to generate funding for the potential implementation of the vehicle ferry concept for Skagit County’s Guemes Island-Anacortes passenger and car ferry replacement.

After an initial review of the Guemes Island Ferry route, Art Anderson Associates proposed to the Skagit County Board of Commissioners the all-electric ferry as a viable replacement for their aging ferry with additional benefits of reducing the lifecycle costs and environmental impacts that a traditional diesel ferry would have. The Skagit County Board of Commissioners signed a resolution on December 29, 2015 directing its Public Works Department to conduct an all-electric ferry propulsion and feasibility study with Art Anderson Associates.

The all-electric ferry being developed will be a practical alternative for operators of ferries throughout the world who want to accomplish zero emissions and achieve a reduction in overall costs of operations. It is projected that the all-electric ferry will reduce owner costs by up to $170,000 per year and will provide an overall breakeven cost after five years of operation when compared to a diesel engine driven vessel.

Two battery banks using low maintenance technology will provide the vessel’s propulsion and power. This clean energy storage uses vanadium flow batteries provided by UniEnergy Technologies (UET) of Mukilteo, WA. This revolutionary battery system combines chemicals in a reduction-oxidation reaction that yields electricity. UET’s batteries are economical, safe, environmentally responsible, and highly reliable. After the batteries have reached the end of their utility, UET handles the decommissioning process and recycles the batteries. This process supports the development of recyclable fuel and eliminates the waste conventional batteries leave at the end of their lifetime.

A key part of the design was building the battery and propulsion system in modular format to permit complete system construction and testing before shipment to the shipyard. “This effectively makes the main power & propulsion system plug-N-play and eliminates a major headache for many small and mid-size yards,” says Payne.

Payne, an expert in electric marine and hybrid propulsion systems, has been designing commercial marine electrical systems since 1993.

The electric ferry also demonstrates energy efficiency and energy conservation. With electric motors and the vanadium flow batteries, the propulsion system’s efficiency is approximately 73%, which is twice the efficiency of a traditional diesel-driven vessel. In addition, the electric ferry supports the conservation of energy by obtaining its power from the electric grid—which in Washington is largely supplied by renewable energy sources including solar, biomass, biodiesel, hydroelectric, and wind power.

The cost of energy for powering the ferry is 30-60% less than for the equivalent amount of diesel fuel required for a vessel of a similar size. This estimation can largely vary due to the fluctuation in oil prices but even on the low end offers significant savings both fiscally and environmentally. The electric ferry project also has the ability to further provide savings by supporting demand-side response and management by charging during the evening when the demand for electricity is low.

The vessel and power system design requires no exotic hull materials and can also be used to retrofit an existing vessel. New all-electric vessel construction costs are estimated at approximately 5% more than an engine-driven version.

“This design concept has the potential to be a true differentiator in the marine industry as an alternative form of vessel propulsion,” stated Eric Engelbrecht, Vice President at Art Anderson Associates. “With demonstrated performance and future advances in battery technology, this propulsion system can be scalable and ultimately contend with other means of propulsion for cost of construction and operation, and have zero environmental impact.”

Seeking Funds
Funding is being sought through a variety of public and private sources. Skagit County has committed funds to conduct a propulsion study on the current ferry route and Art Anderson Associates is developing technical content for further funding outreach.

Currently, Art Anderson Associates is pursuing funding from Washington State’s Clean Energy Fund II, a state funded research, development and demonstration grant for technological advances in clean energy that bolsters the state’s clean tech sector. Funding of the Clean Energy Fund II supports development, demonstration, and deployment of clean energy technologies that save energy and reduce energy costs, reduce harmful air emissions, or otherwise increase energy independence for the state.  

If successful, this project would be the first all-electric, battery-powered vehicle ferry in North America. “We are extremely excited to be working with Art Anderson Associates to conduct a feasibility analysis for this innovative technology that can have so many positive impacts to the citizens of Skagit County, Washington state’s marine industry and the environment,” said Captain Rachel Rowe, Ferry Operations Division Manager for Skagit County.

Benefits of Going All-Electric
The vessel will have zero emissions, which eliminates approximately 650 tons of greenhouse gases annually. This does not include the reduced emissions from the elimination of the transportation and delivery of the 59,000 gallons of diesel utilized by the existing vessel each year.

An all-electric vehicle ferry means direct cost savings to taxpayers and zero-emissions benefits to all environments. This technology will accomplish local, federal and global initiatives to be a zero emission producer and lower our carbon footprint.

Siemens solution for Finnish battery powered ferry

MARCH 7, 2016 — Siemens is to provide the complete electro-technical solution for Finland’s first battery-powered car ferry. The vessel was ordered by Finferries from Polish shipbuilder Crist S.A. last year and

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Electric & Hybrid: Call me Ishmael, no longer

Call me Ishmael. Melville’s famous opening line in his novel Moby Dick refers to an outcast and could once have been the motto of the hybrid and electric marine industry. There were a number of projects where hybrid and full electric drivetrains were prototyped and they worked well…for a while. The limitation was always the battery technology, where lead acid batteries were just not suited to this type of application. As a result, these projects and technologies were “interesting” with “lots of potential” but not a serious technology for the mainstream marine industry.

The advent of lithium ion batteries has fundamentally changed the value proposition for the hybrid and electric drivetrain. These batteries are smart, durable and have a lifetime that will ensure the customer is able to achieve their targeted Return on Investment (ROI). As a result, the hybrid and electric drivetrain has come of age.

To date, Corvus Energy has deployed over 30 MWh of its Lithium Polymer battery-based Energy Storage Systems (ESS) on over 45 projects. These vessels include large and small ferries, offshore supply vessels (OSVs), tugboats, research vessels, luxury superyachts and port cranes. Only two of these applications are for full electric ferries, the remainder are all hybrid vessels, but a common element is that both types of drivetrains make the vessel more efficient, as well as more environmentally sustainable.

Of course an ESS cannot create energy, but only stores it. The ESS therefore enables the vessel to use the cheapest energy available and shift it in time to the point where it is most cost effective. For a full electric this means the ESS is charged from shore using low cost energy and eliminates completely energy generated by costlier, on-board generators. For hybrids, it moves energy from the efficient portion of the generator’s load curve and replaces energy that would have been generated on the less efficient portion of the generator’s load curve.

Full Electric Drivetrains
At one time the round trip efficiency of an ESS was at 70% or less and the energy density was also not very high. This meant an ESS required a LOT of space on a vessel and did not actually store that much energy. The round trip efficiency on the Corvus ESS is now over 95% and the energy density is high enough that a space the size of a 20-foot container can store 650 kWh. This means that an ESS can now deliver enough power and energy to make a full electric drivetrain cost effective. Even with these improvements, full electric drivetrains still work best for applications where the duty cycle is relatively short such as a ferry with a route that is less than an hour between charging points. The 120-car Ampere ferry in Norway, for example, has a route which crosses Sognefjord between Lavik and Oppedal in 20 minutes and then recharges for 8 minutes from a shore-based charging station which uses the grid and another, smaller Corvus ESS to deliver a large amount of power into the vessel’s ESS in a short period of time. The shore-based charging station then recharges from the grid for about 48 minutes until the ferry returns.

The ferry operator, Norled, has other, diesel-fueled vessels on this route and based on a comparison has estimated that the Ampere is saving over 1 million liters of expensive, ultra-low sulfur diesel fuel per year. It is also saving 90% of the maintenance cost of the diesel engines and 100% of the cost of the NOx emissions, which are taxed in Norway. Norled is now looking at expanding the operating hours of the Ampere each day and is examining other routes it operates to determine if they could benefit from a fully electric ferry.

Hybrid Drivetrains
A hybrid drivetrain consists of a either a diesel or LNG engine as the prime generator for the vessel and supplements this engine with an ESS. The ESS is able to charge with energy produced when the engine generator is operating in its most efficient range and then, when the engine generator would be operating in its inefficient range, the engine is shut off and energy is extracted from the ESS to operate the vessel.

A harbor tug is a good application for a hybrid drivetrain. It will typically spend up to 25% of its time sitting and waiting for a call to push a ship. While in this mode, the vessel needs to maintain its position and run its hotel load. The engine is too large to idle and provide power just to the hotel load and so the engine drives its thrusters in opposite directions, thereby keeping the vessel in position but “boiling water” and wasting fuel. With a hybrid system, the engine is turned off and the ESS is used to periodically operate the thrusters to keep the vessel in position, and also serving the hotel load. When the ESS gets to the minimum state-of-charge, the engine is started to charge the batteries, serve the hotel load and run the thrusters. Depending on the hybrid drivetrain configuration, the ESS can also be used to supplement the engine when the tug is pushing or pulling a vessel to get it into position. When the batteries are charged the engine is turned off. An ESS on a tug can save up to 25% on fuel and emissions, as well as reducing maintenance on the engine(s).

An ESS is also very effective to replace the operation of a second engine that is running in spinning reserve to provide emergency power in the event the prime mover generator fails during a critical operation. On the Scandlines ferries in Denmark and Germany they only operate one generator during crossing and use their ESS for spinning reserve. Scandlines have identified 13% reduction in fuel and emissions and a 45% reduction in generator maintenance.

Likewise, Offshore Supply Vessels (OSVs) in the North Sea can use an ESS for spinning reserve during Dynamic Positioning (DP) operation, where the vessels have to be kept stationary when servicing floating oil and gas platforms. DNV-GL has now approved ESS for DP operations. Eliminating the operation of an additional generator used in spinning reserve has the potential to save fuel, emissions, maintenance and even the capital cost of the additional generator.


Key Benefits
The key benefits from an ESS include:

  • Reduced generator hours/generators running in efficient range
    • Reduced fuel consumption
    • Reduced emissions
    • Reduced maintenance
  • Improved capital management
    • Reduced number of generators
    • Reduced size of generators
    • Generator life extension – operation in efficient range provides longer lifetime
  • Emergency backup
    • Spinning reserve
    • Emergency and auxiliary backup
  • Passenger/crew comfort
    • Reduced noise
    • Reduced vibration
    • Reduced fumes
  • Reduced emissions
    • GHG’s
    • Reference air emissions – NOx , SOx , PM
  • Improved performance
    • Better ramping on LNG engines
    • Instant response to throttle
    • Better transient load management

The Future is Now
No longer the elusive white whale, cost effective and proven hybrid electric propulsion has arrived and is here to stay with early adopters now reaping the benefits. An ESS helps owners make their vessels more efficient by helping them manage the operating and capital costs of their vessels, while also making these vessels more reliable and environmentally sustainable. No longer outcasts like Ishmael, the electric and hybrid marine industry has proven the value proposition for electric drivetrains and energy storage. Corvus Energy’s ESS is a key piece of these innovative hybridization projects for commercial vessels, which are fundamentally changing these marine markets. Where once there was only a potential for these benefits, Corvus Energy has the ESS technology, people and experience to make them real.