The time has arrived for safe, drinkable vessel emissions

My wife and I were planning to spend the day in Port Townsend, Wash., and were among the 20 or so passengers waiting for the Washington State Ferry to arrive when we heard someone calling our names. It was Garrett, a friend who makes a very good living putting in solar and wind power installations, going over to check on his latest project. As the ferry backed down to make its landing, a billowing cloud of diesel exhaust emanated from the stack, enveloping those of us in the waiting area. After he finished coughing, Garrett said, “You’re a mariner, Kelly. Why are these boats still running on the same polluting diesel engines they’ve used for who knows how long? When is the ferry system going to join the 21st century?”

He had a good point. With some ships in the fleet close to 65 years old, Washington State Ferries vessels burn about 20 million gallons of diesel fuel each year, putting around 180,000 metric tons of carbon dioxide, methane, nitrogen oxide and other greenhouse gases into the air. The state has announced a goal of replacing the old soot-billowing workhorses with diesel/electric powered ferries by 2050. If that plan comes to fruition 26 years from now, around 5 million metric tons of toxic emissions will have been released into the air while waiting for the new vessels — and 45,000 metric tons of toxic emissions will continue to be released annually into the atmosphere after they are built. I told Garrett the news about how the maritime industry is beginning to embrace various forms of alternative energy to run ferries and other vessels, most recently hydrogen power.

Employing hydrogen power involves the use of PEM (polymer electrolyte membrane) hydrogen fuel cells. Similar to electric power, the big difference is that as long as they have a fuel source, in this case hydrogen, they don’t need charging. If the hydrogen fuel cells are paired with a traditional diesel engine, emissions can be reduced by 40 percent or more. A vessel relying solely on hydrogen power emits no air pollution — only water vapor.

The start of using hydrogen to help power commercial vessels began in Norway on March 31, 2023, when the Norwegian Maritime Authority gave its final approval for the operation of MF Hydra. Utilizing standard electric power along with hydrogen fuel cells, this hybrid 270-foot ferry can reach a top speed of 9 knots while carrying up to 295 passengers and 80 vehicles. A new generation of larger and faster hybrid hydrogen-powered ferries are under construction in Norway for use on the 50-mile trip from the mainland to the Lofoten Islands — a popular tourist destination. Designed to operate at least 85 percent of the time on hydrogen fuel cells at speeds close to 20 knots, these 380-foot roll-on/ roll-off passenger (ro-pax) vessels will have capacity for 120 cars, 17 freight trucks and 599 passengers.

The United States is beginning to embrace hybrid hydrogen fuel cell watercraft: on U.S.-flag short-sea containerships, tugboats, crew boats and oceanographic vessels. Earlier this year, the University of California’s Scripps Institution of Oceanography, which I’ve sailed for and found to be a very environmentally conscious vessel operator, announced that it has received approval for the first hydrogen-hybrid oceanographic ship. The vessel will only use hydrogen fuel cells in California state waters, with traditional diesel engines being a second source of power when needed offshore.

On July 19, 2024, San Francisco’s Blue & Gold Fleet began operating M/V Sea Change, the first commercial ferry to operate entirely on hydrogen fuel cells. The 70-foot, 75-passenger catamaran has a 300-mile range, with a top speed of 15 knots. Designed by Switch Maritime Corp. in California and built in Bellingham, Wash., at All American Marine, only water vapor is released when the vessel is underway. Some of the water vapor is re-mineralized and used in the onboard drinking fountain, making it the only vessel in the world with drinkable emissions.                                               

From an environmental point of view, the use of hydrogen fuel cells is promising. After all, who would argue that reducing air pollution and toxic emissions isn’t a good thing? There are, however, significant concerns.

Hydrogen is extremely flammable and prone to explosions, much more so than gasoline or propane. When used onboard a vessel as a fuel source, it is usually stored in one of two ways: as a gas compressed in tanks at pressures ranging from 5,000-10,000 psi, or as a liquid at an extremely cold temperature close to -500 degrees Fahrenheit. At those extreme pressures and temperatures, a tiny crack in a storage tank could cause a devastatingly sudden release of hydrogen — enough to kill a crewmember due to lack of oxygen or severe frostbite, or to spontaneously ignite a fire from a heat source as small as a light bulb.

The International Maritime Organization has not formally established requirements for vessels utilizing hydrogen fuel cells — something it hopes will be accomplished by 2026. Here in the U.S., the American Bureau of Shipping (ABS) has developed certain standards applicable to hydrogen-fueled vessels, focusing on things such as their construction, location of storage tanks and ventilation of engine room spaces — which even it admits are works in progress. As ABS Vice President of Technology Gareth Burton recently stated, “ABS is working with leading organizations to support the safe development and use of hydrogen as a marine fuel. The requirements we have developed are a key step toward supporting vessels on their decarbonization journey.”

I am all for using different ways to propel vessels through the water — including biodiesel, electric batteries, wind power and hydrogen — but only if proven safe. Until then, these systems should continue to undergo rigorous testing before being fully employed on commercial vessels, ferries and oceanographic ships. Let’s hope we are not putting the proverbial “cart before the horse.”                                                                                               

Till next time I wish you all smooth sailin.,’

Capt. Kelly Sweeney holds the license of master (oceans, any gross tons) and has held a master of towing vessels (oceans) license, as well. He has sailed on more than 40 commercial vessels and lives on an island near Seattle. He can be contacted by email at captsweeney@outlook.com