Feasibility design (technical and economic), according to the documents specified in the Design Guidance Document (DIP), for the construction and commissioning of an on-shore power supply (cold ironing) system for the medium-voltage (MV) electrical power supply of cruise ships and various types of vessels in the ports managed by the Port System Authority of the Sea of Sardinia.

The design covered the following seven ports:

• Port of Cagliari - Historic Port (2 berths serving cruise ships);
• Port of Cagliari - Porto Canale (5 berths serving Ro-Pax ships);
• Port of Portovesme (1 berth serving Ro-Pax ships);
• Port of Olbia Isola Bianca (1 berth serving cruise ships, 3 berths serving Ro-Pax ships);
• Port of Golfo Aranci (1 berth serving Ro-Pax ships);
• Port of Porto Torres (3 berths serving Ro-Pax ships, 1 berth serving cruise ships);
• Port of Santa Teresa Gallura (1 berth serving Ro-Pax ships).

The activities included the adaptation of the medium-voltage (MV) power supply system on the user side, the distribution system, and the energy delivery system at the quay, tailored for each ship/port type.

The cold ironing system design was carried out in compliance with IEC 80005-1 ("Utility connections in port - Part 1: High voltage shore connection (HVSC) systems - General requirements") and IEC 80005-3 ("Utility connections in port - Part 3: Low voltage shore connection (LVSC) systems - General requirements"). For the MV systems, ships will be powered at 6.6kV or 11kV with a grid frequency of 50Hz or, via a frequency converter, at 60Hz. For low-voltage Ro-Pax applications, voltage levels of 400V, 440V, and 690V at 50Hz grid frequency will be available.

The designed electrical and special systems are: medium-voltage electrical system with low-voltage transformation and distribution, main and secondary electrical panels with distribution system, standard and emergency lighting system, FM system, grounding system, uninterruptible power supply (UPS) units, fire detection system, and frequency conversion for ship power supply at 50Hz or 60Hz.

The project also includes monitoring and control of all systems supporting the cold ironing installation to automate ship-to-shore connection operations, reducing operational times and minimizing the risks associated with potential handling errors of electrical equipment. For the automation system, the IEC 80005-2 standard (“Utility connections in port - Part 2: High and Low voltage shore connection systems - Data communication for monitoring and control”) applies.

The mechanical systems were designed to ensure the proper operation of the electrical and electronic equipment installed inside the newly constructed technical rooms. These consist of cooling and ventilation for switchgear rooms (frequency converters, MV switchboards, LV switchboards, UPS units, and batteries) and mechanical ventilation for transformer rooms.