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Tough Cell


With its electro-hydrogen system, the Hynova 40 is poised to be the first-ever production boat to use hydrogen power.

The hydrogen fuel cell is about to splash into recreational boating. Like traditional batteries, hydrogen fuel cells produce electricity without any combustion or emissions. Unlike batteries, however, hydrogen cells do not run down or need to recharge as long as there is a constant source of fuel.

Hynova Yachts, based in France, is among the first builders to embrace hydrogen as a source of fuel, and its prototype 40-foot powerboat plans to use Toyota’s REXH2 fuel cell for power. With twin 150-kW electric engines, the Hynova 40, an open-design yacht tender, projects to hit a top speed of 25 knots and cruise at 15 knots.

Toyota is heavily invested in hydrogen fuel cells, using them in buses, trucks and high-speed ferries. They’ve sold more than 10,000 Marais, a fuel-cell equipped car. Toyota marinized the Marai’s cell, adding a water-cooling system and filters to keep salt from getting into the internal workings when engineering the REXH2 cell. It’s a step in the right direction, and Hynova is not the only builder using the REXH2. The Energy Observer, a 100-foot catamaran that uses wind, solar and hydrogen power, has traveled 7,000 nautical miles with Toyota’s cell onboard.

The team behind Energy Observer collaborated on the Hynova 40, which in addition to its twin electric engines and battery bank will also carry a 60-kW REXH2 cell and 30-kg hydrogen tanks. The REXH2 uses hydrogen to create electricity, which flows to a battery bank. The batteries provide a well of energy to meet momentary demands—acceleration and seafaring—while the cell extends the vessel’s range. The cell can also power onboard systems while at anchor. The entire system is silent and carbon neutral.

For higher output needs, installers can arrange cells in sequence, and since they are small and modular, they can be spread through the hull to fit within various designs. That modularity also means that if any one cell malfunctions, the rest will continue to operate, providing built-in redundancy.

Despite the benefits of hydrogen, hurdles remain. For starters, not all hydrogen is created equal. Separating it requires energy, and if electricity generated by traditional resources (gas or coal) instead of renewable ones (solar or wind) is used, it undercuts the environmental benefits. Hydrogen is also hard to obtain—you can’t just pull up to the fuel dock and plop down a credit card, at least not yet. Various entities are building infrastructure, but it’s going to take time. California has 40 stations for hydrogen cars and several dozen more under construction with a goal of 1,000 by 2030. And a French company, Air Liquide, is building two commercial hydrogen production facilities in the U.S.

Even when you can find hydrogen, it isn’t cheap. According to multiple sources, the energy equivalent of a $2.50 gallon of gas would cost about $5.50 to $6 in hydrogen. Opinions vary about future cost reductions, but a study published in the February 2019 issue of Nature projected “green” hydrogen (produced by renewables) will cost about the same as combustible fuels by 2030.

There are durability questions, too, and while more recent cells showed improvements, they have not yet reached the standards set by industry and governments. As with the solar vs. wind debate, the plug-in electric vs. hydrogen argument is a bit of a false dichotomy. It’s clear that the world will need multiple technologies adapted to specific uses to solve its energy problems, which is why the Hynova and its fuel cell are worth watching. But you may want to hold off on installing hydrogen tanks—for now.

This article originally appeared in the March 2021 issue of Power & Motoryacht magazine.