U.S. Fuel Cell Ferry Feasible, Expensive
The U.S. Maritime Administration (MARAD) has released a feasibility study that examines the technical, regulatory and economic feasibility of a high-speed passenger ferry powered solely by hydrogen fuel cells and its associated hydrogen fueling infrastructure in the San Francisco Bay.
The study determined that it is possible technologically to build and to operate a 150 passenger, high speed, zero emission hydrogen-powered ferry and its associated hydrogen station in the current regulatory environment. However the current ferry design has a cost premium compared to a conventional diesel ferry.
Through examination of the options, the project team selected proton exchange membrane (PEM) fuel cells for the power plant due to their low weight and volume, commercial availability, proven track record, zero emission characteristic, and acceptable power performance.
A catamaran was chosen rather than a monohull or trimaran. This decision had more to do with the 35 knot speed requirements of the ferry rather than the hydrogen fuel cell power plant, but it has the resulting advantage that a catamaran is more stable than a monohull, allowing placement of the liquid hydrogen tank on the top of the vessel while still maintaining the required stability.
ABS and the U.S. Coast Guard determined that the properties of liquid hydrogen were similar enough to LNG for the IGF Code to be regulatory starting point. However, there are some critical differences, such as the very high buoyancy of liquid hydrogen and the ability of liquid hydrogen to condense the components of air (nitrogen and oxygen). It was decided that the vessel, SF-Breeze, would be built and regulated in accordance with 46 CFR Subchapter T – Small Passenger Vessels, which applies to vessels with 150 passengers or less and less than 100 tons gross weight, but the IGF Code will form the basis for the hydrogen and fuel cell features which are not included in the Subchapter T regulation. ABS Rules for High Speed Craft were also adopted along with a dozen other regulations, standards, and guidance documents to fill in the gaps in the existing marine regulations.
Due to the difference in characteristics between diesel engines and PEM fuel cells, SF-Breeze is expected to have several key advantages:
• eliminate air emissions
• Superior response time during power changes (such as during maneuvering)
• Less noise and vibration on-board
• Elimination of diesel fuel spills, diesel odor, and exhaust odor
Five-year fuel costs at today’s prices were compared for the SF-Breeze and a similar diesel ferry using today’s ultra-low sulfur, non-road fossil diesel rate, and it was determined that today’s fuel cost for the SF-Breeze would be three to five times higher for the non-renewable liquid hydrogen and five to 16 times higher for 100 renewable liquid hydrogen.
Cost reduction strategies specific to the vessel design and strategies for leveraging developments in the fuel cell technology are now being explored.
The study was funded through MARAD’s Maritime Environmental and Technical Assistance (META) Program and conducted by Sandia National Laboratories. Other participants included Red and White Fleet, Elliott Bay Design Group, the U.S. Coast
Guard and American Bureau of Shipping (ABS).
The report is available here.