Yamaha Motor Co. has announced they will reveal a hydrogen-powered outboard prototype at the upcoming Miami International Boat Show.
The event runs February 14th-18th in Miami, Florida, USA.
There have been undercurrents from Yamaha about hydrogen power in recent months, notably their partnership with Toyota in 2022 to develop a hydrogen engine for automotive applications. That joint effort resulted in a 5.0 liter V8 engine with 100% hydrogen power.
As for marine development, Yamaha said in a press release that any new propulsion system must put emphasis on overcoming water resistance. Because water has greater resistance against a hull compared to an automobile on a road, hydrogen marine engines will require development to produce enough energy to overcome frictional forces.
According to Yamaha, the performance and engineering requirements will vary depending on the usage environment -- such as oceans, rivers, or lakes -- as well as the usage itself from commercial fishing to recreational boating. That will likely to translate to variable power options depending on boat size, weight, and application. However, the pace of advancement will depend on hydrogen engines becoming more widely produced and palatable across the industry.
Yamaha is promoting what they call "a multi-directional development approach" to coincide with a commitment to achieve carbon neutrality by 2050.
The details of the engine are scarce, but the company's 2024 Marine Technology Briefing says Yamaha USA will focus on boat development while Yamaha Japan will focus on engine development. Hull designs and floorplans will almost certainly have to be redesigned to accommodate a fuel cell.
The photos released by Yamaha show the cowling with a V8 emblem and a 5.6L designation. While it isn't confirmed that the two engines are related, those figures are similar to the automotive engine developed with Toyota in 2022 for the Lexus RC F sport coupe. Converting the automotive powerhead required modifications to the injectors, cylinder heads, and intake manifold. The automotive version delivered up to 450 hp at 6800 rpm and 540 Nm of torque at 3600 RPM, which is below gas-powered equivalents, but offers the upside of reduced maintenance, lower overhead, and a quieter ride.
With respect to the evolution of hydrogen propulsion in boats, when hydrogen burns it combines with oxygen to produce water or water vapour. An environmentally-friendly emission like water vapour would have obvious benefits in the marine industry compared to carbon dioxide, hydrocarbons, and other particulates produced by gas-powered engines. Hydrogen propulsion also typically requires a high-pressure fuel cell and battery bank to feed the motor. The world's first hydrogen powered RIB from H2C Boat announced earlier this year utilized a 51 kWh fuel cell behind the helm, which fed a Torqeedo Deep Blue 50R electric outboard to propel the 20-foot boat to a top speed of 28 mph (45 km/h).
Another possible upside to hydrogen outboards is the similarity in sound between hydrogen and gas-powered engines. While other alternatives like the turbine engine have potential to be more efficient, their high RPM range is extremely loud. The noise produced by a turbine also occurs at a higher frequency. Hydrogen engines developed thus far sound similar to traditional gas-powered engines, albeit with better emissions and with simpler exhaust requirements. For boaters who enjoy the rumble of a well-torqued gas engine on the transom, the hydrogen engine may be more appealing when cruising.
You can watch the Yamaha Marine 2024 briefing about the hydrogen engine below *skip to 26:00 mark with subtitles on*
