Hydrogen rides the waves of technological innovation

This article originally appeared in the Aug'23 magazine issue of Electronic Specifier Design – see ES's Magazine Archives for more featured publications.

When the International Marine Organisation announced its ambition to cut greenhouse gas emissions by at least 70% from 2020 to 2050 and CO2 emissions by the same amount, the bold move raised many questions. The primary one was, what would replace the fossil fuels used in boat and ship engines and motors?

Game-changing gas

One option is hydrogen. Lara Pomaska and Michele Acciaro, from the Hapag-Lloyd Centre for Shipping and Global Logistics in Hamburg, Germany, proposed hydrogen in a transportation research article in 2022. “Hydrogen has the potential to become a competitive alternative fuel in the maritime sector, thanks to its zero tank-to-propeller emissions,” they wrote.

An attractive characteristic is that hydrogen is safe and can be economical because it can be used in existing vessels. In its liquified state it can be used in modified gas turbines or internal combustion engines. Pomaska and Acciaro believe that it is the most likely alternative to fossil fuel if a CO² tax is imposed, adding that if the rate of progress continues, hydrogen is likely to be competitive without a CO² surcharge by 2040.

In addition to very low emissions and zero CO² emission during the combustion phase, it is also plentiful and can be produced by renewable energy sources.

Another advantage is that it has a high gravimetric energy density, i.e., Wh/kg. Its energy density by volume is relatively low, however, which means hydrogen needs to be compressed at high pressure (typically 250 to 500 bar) for storage at temperatures of -253°C. Liquified hydrogen needs to cryogenically stored in well-insulated tanks.

Another metric for economically evaluating hydrogen is WTT (well-to-tank) emissions. These are high for hydrogen but can be overcome by using renewable energy, such as wind, nuclear, solar, or hydropower sources.

Probably the best argument for hydrogen is that it is non-toxic and evaporates when it is expelled – or if there is a spill.

If the idea floats

In April 2022, Torqeedo announced a collaboration with Proton Motor Fuel Cell to integrate hydrogen fuel cell charging into its Deep Blue battery in propulsion systems for electric boats. The hydrogen-electric Deep Blue Hybrid system will allow for fast fuelling but will also overcome speed and range limitations while meeting emission requirements. 

The system will provide propulsion power ranges from 50kW to 200kW and fuel cell power of 30kW to 120kW. The collaboration is part of the Marine-Hydrogen-Hybrid project with funding from the Bavarian federal government.

World Sailing Championships

In this year’s World Sailing Championships, the Dutch entry, Watersportverbond, will coach its team from a hydrogen-powered vessel. The H2C Boat is powered by a 40kWh Deep Blue electric motor, with an additional 51kWh hydrogen capacity, and uses a hydrogen fuel cell as a range extender.

The boat was developed by the Dutch startup H2 Marine Solutions, with partners including Torqeedo and the Delft University of Technology (TU Delft). Torqeedo provided the Deep Blue 50R outboard motor and Deep Blue 40 Li-ion battery. The six metre long boat has a minimum operating time of five hours on the water and can reach up to 45kmph.

Fabian Bez, CEO of Torqeedo, says: "Sailing is all about harnessing the power of nature, wind, and waves. Now, the highest levels of competitive sailing can achieve the range, runtime and performance they need in a coach boat, emission-free.”

Marcel Schaap, Founder and Managing Director of H2 partner, De Stille Boot [the Silent Boat, a Dutch electric sailing company], looks further ahead when he says: "The presence of hundreds of coach boats at the World Championships showcases the potential of this project in reducing the carbon footprint of sailing events."