Windcat presents first H2-capable Elevation series CSOV

The vessel can accommodate 120 people and will support the construction, commissioning and maintenance of offshore energy projects, which it does not specify.

The vessel has been built with CMB.Tech’s CMB.Tech’s hydrogen technology, a dual-fuel hydrogen engine which allows the auxiliary genset to run on hydrogen. Windcat says the genset, storage and fuel supply system are ready for integration on the vessel ‘once final approvals are in place’.

At the moment the vessel has a hybrid diesel-electric propulsion system with four 1800 azimuth thrusters by Schottel and a 1700kW battery by Corvus Energy. Its three main engines are one ABC 12DZC 2390kW and two ABC 8DZC 1672kWs.

“This approach supports future regulations for hydrogen use in medium-sized vessels,” it says, and builds on operational experience the company has with hydrogen-powered Crew Transfer Vessels.

Future fuels?

There is a long way to go before today’s ‘alternative fuels’ will make commercial sense on a meaningful scale.

Producing one tonne of hydrogen needs approximately 50,000 to 55,000kWh of electricity, between 180,000 and 198,000 megajoules (MJ). In return, hydrogen yields about 120,000 MJ (LHV) or 142,000 MJ (HHV) per tonne – far less than the energy required to produce it.

“Hydrogen fuel costs remain significantly higher than gasoline and hybrid alternatives,” says Gary Yowell, senior analyst at Stillwater Associates. “In 2025, retail prices in California exceeded $32/kg, making hydrogen four times more expensive per mile than gasoline.”

Methanol has a more energy-efficient production profile, but still uses more energy to produce than it yields.

Green methanol, synthesized from carbon dioxide and hydrogen, requires 10,000 to 11,000kWh per tonne – about 36,000-39,600 MJ. Its energy yield stands at about 19,800 MJ.

Cost is where methanol currently shines. Green hydrogen production costs range from $3,000 to $8,000 per tonne, depending on location and electricity prices. Green methanol costs between $900 and $1,200 per tonne. When evaluating cost per MJ of usable energy, methanol proves more economical, especially at the lower end of its price spectrum.