Gas turbines form the heart of our ship. It is this technology in combination with steam turbines that enable current speeds and service levels to be maintained – and cuts emissions to zero. Gas turbines have long been used in industry, but it is only now that they can be powered by hydrogen. This provides a unique opportunity to accelerate the environmental transition of shipping.
In addition to speed, a major advantage with the gas turbines on Gotland Horizon is that in addition to hydrogen they will be designed for use with several different types of fossil-free fuels, so called multi-fuel. Apart from hydrogen, fuels such as methanol, e-methanol and biogas (LBG) could be used. With relatively simple adjustments, it will be possible to power the vessel’s turbines with gas and liquid fuel, as well as hydrogen. It will also be possible to mix hydrogen with biogas.
A turbine converts energy from a liquid or gas into mechanical motion. A typical gas turbine unit with a generator is 14 metres long, weighs about 85 tonnes and has an output of up to 15MW. In many ways, the technology is similar to an aircraft engine: at one end, air is sucked in and compressed in the compressor. The pressurized air is then passed into the combustion chamber where hydrogen gas enters and ignites the mixture. The combustion of gas drives the turbine. The turbine drives a mechanical shaft that is connected to a generator or directly to the propeller shaft via a gearbox.
The gas turbine is also combined with a steam turbine, which is placed below the smaller funnel on the topside of the ship. The steam turbine uses residual energy, i.e., the water vapour generated during combustion and produces electrical power for the ship.
Gotland Horizon is designed for multi-fuel with a focus on hydrogen. Depending on availability and technological developments, the vessel can be adapted to be powered using other available fossil-free fuels. This means that Gotland Horizon will be well equipped to achieve an efficient transition to zero emissions.