The "Four Major Problems" of Hydrogen Ships

Under this situation, hydrogen-powered ships have an opportunity for development. In order to seize this opportunity, many domestic fuel cell companies are accelerating the launch of marine fuel cell systems and obtaining classification society type approval certificates. At the same time, there are also good news about the construction and launch of hydrogen-powered ships. However, at present, hydrogen-powered ships are mainly small-scale demonstrations in inland rivers and offshore areas, which is far from the industry's expected widespread application. This is mainly because the development of hydrogen-powered ships is still facing four major problems: the power system technology needs to be verified, the hydrogen storage technology is difficult to meet the demand, the hydrogenation method is difficult to choose, and the application scenario is difficult to expand. How to break the deadlock?

The focus of the industry discussion is whether it is necessary to specialize in marine fuel cells. Some people believe that directly using the automotive fuel cell system will save more costs and be more efficient. It only needs to be improved according to the type of ship to adapt to the use scenario of the ship.

Another part of the view is that ships and vehicles are in aquatic and terrestrial environments respectively, and the operating environments are quite different. Marine hydrogen fuel cells cannot be directly transplanted to automotive hydrogen fuel cells. They need to be specially designed and updated according to the complex water environment of the ship, large hydrogen consumption, high cruising range and safety requirements, so as to accelerate the promotion of hydrogen ships with power systems adapted to marine scenarios.

The marine hydrogen storage system needs to select a specific hydrogen source according to the water area, ship type, emission requirements, etc. At present, the development of 35MPa high-pressure gas cylinder hydrogen storage technology has been relatively mature. Some people suggest that this hydrogen storage technology should be used first, so that the operation will be more reliable.

However, this suggestion has been opposed. The marine hydrogen storage system has very high requirements for energy density. The energy density and endurance of gaseous hydrogen storage cannot meet the needs of hydrogen-powered ships. The senior management of a certain company clearly stated that they prefer the liquid form with high energy density: "The volume energy density of the gas is always limited, so in the future I am optimistic about liquid, liquid hydrogen, liquid ammonia, methanol, and even organic liquid hydrogen storage."

At present, hydrogen refueling methods for hydrogen-powered ships include on-board production and use, refueling at docks, and lifting and replacing hydrogen bottles. The tank truck mobile refueling method used abroad is quite arbitrary, and there are attempts to build fixed stations for energy replenishment in China. For example, the "Three Gorges Hydrogen Boat 1" refueled at a self-built inland wharf-type hydrogen production and refueling integrated station. The station uses the electricity of the Three Gorges Power Station to electrolyze water to produce hydrogen. The ship uses a folding mechanical arm to pull a high-pressure hose for hydrogen refueling.

It should be noted that due to the unique conditions of each water area, it is not necessarily necessary to choose the above-mentioned station construction method. An industry expert suggested that you choose according to your own conditions: on the one hand, it is expensive to build a hydrogen refueling station, and the stations may not have power resources like the Three Gorges area; on the other hand, the refueling connection method also needs to strictly prevent hydrogen leakage. Once an explosion occurs, the consequences will be disastrous. If the hydrogen storage bottle is directly transported on board for replacement by hoisting, it will not only be safer, but also faster and more economical. This may be a starting point for opening up the market for hydrogen-powered ships.

At present, the scenes of hydrogen-powered ships are concentrated in small-scale demonstration official ships, sightseeing, container shipping, etc., but the real market has not yet been opened. Gaogong Hydrogen and Electricity learned that at present, shipowners are reluctant to apply hydrogen-powered ships, mainly because the cost is too high.

Unlike cars, each component of a ship needs to be certified and approved by the classification society, and the initial cost is very high. In addition, there are technical research and development and iteration costs, investment and operation costs, and maintenance costs.

"Now hydrogen-powered ships are mainly demonstration-type, not market-type. The cost is too high, and it is difficult for shipowners to accept it. If there are subsidies, they may be used, but there are no subsidies in this regard now, and the economic accounts cannot be calculated." A senior industry insider told Gaogong Hydrogen and Electricity that in order to reduce costs, it is still necessary to improve the reliability of technology and products, but this is a paradox. Products are iterative. How can we improve them with so few demonstrations? Unless it is "auxiliary promotion" instead of "main promotion".

Under the condition of technical limitations, ships using a combination of electricity and hydrogen energy may have great advantages in some ports that have introduced oil bans. By acting as an "auxiliary propulsion" for electric ships, it can make up for the disadvantages of electric ships' endurance problems, and at the same time accumulate practical application experience and feed back to technology research and development.

Overall, the market promotion of hydrogen-powered ships has a long way to go. But there is no need to be too pessimistic. At present, countries around the world have increasingly stringent requirements for ship carbon emissions. For example, Arctic shipping will ban the use of heavy fuel oil from July 1, 2024. In this case, hydrogen-powered ships will surge into a blue ocean in the future.

It's just that the transformation of the energy system is not achieved overnight. The industry needs to face up to the four major problems that exist today, and continue to work hard to solve the problems from the aspects of technical exploration, industrial ecology, cost reduction, and standard setting. There will always be a bright day.