Feasibility of the Zero-V: A zero-emissions hydrogen fuel-cell coastal research vessel

Abstract

A study is presented to determine the technical, regulatory, and economic feasibility of a coastal research vessel (named the “Zero-V”) powered solely by hydrogen fuel cells. Feasibility is examined in the context of science mission profiles of particular significance in coastal oceanography that require a modern, capable, general-purpose coastal research vessel. These missions translate into the primary Zero-V vessel requirements against which technical feasibility is assessed. Hull form analysis indicated a trimaran design enables a vessel that can meet all of the space and volume requirements as well as for fitment of the machinery, service, and control spaces necessary for operation of the vessel. To meet speed and range (endurance) requirements, the vessel needs to be constructed of aluminum to reduce weight. The beam (56 feet), length (170 feet) and draft (12 feet) of the vessel enable it to dock at all primary ports of call. With 1800 kW of installed proton exchange membrane (PEM) fuel-cell power for primary propulsion, the cruising speed is 10 knots. With 10,900 kg of consumable LH2 stored in two LH2 tanks, the range of the vessel is 2400 nautical miles, with an endurance of 15 days. Both the greenhouse gas (GHG) and criteria pollutant (NOx, HC, PM10) emissions were estimated based on a complete “well-to-waves” (WTW) analysis. Using renewable hydrogen, the annual WTW GHG emissions predicted for the Zero-V are 91.4% less than those from an equivalent vessel running on conventional diesel fuel. Analysis of the WTW criteria pollutant emissions show that hydrogen PEM fuel-cell technology can reduce these emissions below stringent U.S. Environmental Protection Agency (EPA) Tier 4 marine diesel engine emissions limits regardless of whether the hydrogen is made using natural gas or renewable methods.The capital construction cost is estimated to be ~ $79 M, not unreasonable when compared to other modern diesel-fueled research vessels of similar size and capabilities. The operations and maintenance (O&M) costs of the Zero-V were estimated to be 7.7% higher than operating the equivalent diesel-fueled vessel at the assumed fuel prices for LH2 made from steam reforming of fossil natural gas. The approach to safety for the Zero-V is described in terms of the arrangement of hazardous areas on the vessel. Regulatory review of the vessel design by the United States Coast Guard (USCG) and the Class society DNV GL found no fundamental or “show-stopping” design concerns that would prevent eventual deployment of the Zero-V. Overall, this study found it feasible from technical, regulatory, and economic perspectives to design, build and operate a coastal research vessel powered solely by hydrogen fuel cells.