Green power for UASC container ships

Using a waste heat recovery system (WHRS), exhaust gas from the propulsion main engine is used to produce additional electrical power from the ship’s exhaust gas in a clean and efficient manner. Siemens says this allows power to be generated with a lower overall fuel consumption while also reducing CO2 emissions by up to 12%.

“Together with UASC we worked as partner to adopt and comply with the very complex technical specifications from UASC. Due to extraordinary reduction of fuel cost the total cost for container transportation will be reduced significantly,” said Stefan Kraus, head of strategy, marine and shipbuilding, Siemens Drive Technologies.

“This fuel saving also results in lower CO₂ emissions of the same amount,” he added.

The drive system is a shaft generator which operated both as motor or generator and is automatically adapted to suit the requirements in hand by a higher-level power management system. This is said to enhance the efficiency and flexibility of the power generation process as well as reduce wear on the main drive and the auxiliary generators.

To achieve the maximum propulsion power on the shaft line, surplus electric power can be used to boost the ship’s propulsion system by means of the shaft generator and the Sinamics S120 frequency converter in the so-called power take-in (PTI) mode. The generator is mounted directly on the propeller shaft without gears and affects it directly. At low main engine load, it operates as a generator in power take-off (PTO) mode to supply the electric mains.

The class A-14 and A-18 UASC container ships have a carrying capacity of 14,500 and 18,800 teu and are among the largest container vessels in the world.