Siemens constructs Germany’s first commercial shoreside power supply system for ships berthed in port

“As soon as the ships obtain the power they need via our shoreside power supply system, they can switch off their diesel generators while they’re berthed in port. These diesel generators not only produce electrical power but also exhaust emissions, soot, particulate matters and noise, so in this way these ships will help to reduce “harbor smog” which is becoming an increasingly serious environmental problem in many port cities,” said Ralf Christian, CEO of the Power Distribution Division in the Siemens Energy Sector.

The Transatlantic ships with their 400-V/50-Hz on-board systems have already been retrofitted for the Finnish shoreside power system and have a cable drum with plug-in connector, a control system for the coupling process and a transformer on board. In Lübeck, Siemens is installing the matching connecting point on the dock and creating the connection to the medium voltage network of the Lübeck municipal utilities. For this purpose, the company is installing a 10-kV switchgear for connection to the utilities and a 6-kV switchgear for connection to the on-board system. A cast-resin insulated transformer rated at 2500 kVA is also being installed in a concrete substation on the harbor site for separating the two networks electrically. Another component of the shoreside connection is a smaller concrete substation with a 6-kV outlet at its side enabling power to be obtained from the dockside via the plug-in connector of the ship.

The Lübeck shoreside power supply system operates at 50 Hz only because the on-board system of the ships uses the same frequency as the local power supply network. However, about 80 percent of the ships cruising the world’s oceans are equipped with a 60-Hz on-board system. If these ships are to be supplied with shoreside power, the frequency would have to be adapted. For this purpose, Siemens has developed the cold ironing system Siharbor, which enables on-board systems of ships and power supply systems on land to be connected together despite different voltages and frequencies.

The core element of this shoreside power supply system is the Siplink system developed by Siemens (Siemens Multifunctional Powerlink), in which two converters are connected together by a DC link and are each connected to one power supply network. In this way, Siplink can not only feed a separate network from a distribution network but can connect power supply systems with different parameters and interconnect them. Both these capabilities are used in the Siharbor solution as a means of linking the ship’s on-board system to the local power supply network.

In order to use the Siemens solution, both the harbor and the ship must be specially equipped for the shoreside power supply, among other things with a plug-in connection system. After connecting the plug-in connector of the ship, the automation system installed on shore can automatically initiate the start up of the shoreside power supply system. The user dialog for this is conducted from the ship. The ship’s power supply is not interrupted. Siplink is self-synchronizing and takes over the power supply within a few minutes. The diesel generators of the on-board power supply can then be shut down and the complete on-board network is supplied in an environmentally friendly way from the shore side power supply system.