Hydrogen is one of the future fuels and a key component in the transition to a climate-neutral society for many industries, including shipping. And it is easy to understand why, as the combustion of hydrogen generates a single emission: water.
Hydrogen gas consists of two hydrogen atoms (H2), which is also the most common element. The gas is a so-called energy carrier, which means that when it comes into contact with oxygen during combustion, large amounts of energy are released. When it reacts with oxygen (O), H2O is formed: plain water. To convert hydrogen gas from being an energy carrier into electricity, it needs to be passed through a gas turbine, fuel cell or internal combustion engine.
We are working on being able to handle hydrogen gas at room temperature, for example by compressed hydrogen which is the most efficient. The alternative of cooling hydrogen to liquid form, (-253 degrees Celsius), requires more energy than keeping it in gaseous form at room temperature. It will be able to store the gas in containers on cargo decks on board ship or in dedicated tanks.
The production of hydrogen can take place in many different ways, using fossil and fossil-free sources. Gotland Horizon will be powered exclusively by fossil-free hydrogen. One way to develop gas like this is through electrolysis. This means that electricity from wind power, solar energy or hydropower, is used to split water into hydrogen and oxygen.
We chose hydrogen due to the amount of energy required to power a ship. At present, batteries cannot meet the demands of ships sailing between the Swedish mainland and Gotland. However, it is possible to use batteries as a complement to primary power sources when arriving in and leaving port, which we are already reviewing the possibilities for on our existing ships.
Gotland Tech Development, which is developing Gotland Horizon, is participating in several collaborative projects with the aim of producing fossil-free hydrogen in Sweden, including the storing and infrastructure of hydrogen.