Onshore power supply system for the port of Aarhus

The Port of Aarhus has set itself the goal of substantially reducing CO₂ emissions and creating a sustainable energy supply for ships while docked in the port. To this end, a modern onshore power supply system is being established at the existing container terminal. Inros Lackner SE is providing planning, design and consultancy services, helping to make the port future-ready and more environmentally friendly. The project will be implemented in two phases, with a strong focus on compliance with international standards and on achieving maximum flexibility.

Technical requirements and standards

The design of the onshore power supply system in the Port of Aarhus is based on the international standard IEC/IEEE 80005-1, which sets out clear requirements for the connection of container ships. According to this standard, each connection point must provide an output of 7.5 MVA at medium voltages of 6.6 kV or 11 kV and at frequencies of 50 Hz and 60 Hz. These specifications ensure a reliable and flexible power supply that meets the needs of modern container and feeder ships. At a power rating of 7.5 MVA, for example, a ship can draw enough energy to supply around 4,500 households. This example illustrates how powerful the planned onshore electricity supply facilities will be. (Quelle: Bundesverband der Energie- und Wasserwirtschaft (BDEW), Durchschnittlicher Haushaltsstromverbrauch, 2023)

At the heart of the project is the Onshore Power Station (OPS), which ensures reliable electricity transfer to the docked ships. To provide the required power, several container-style transformers are connected together. This enables electricity to be supplied at frequencies of 50 Hz or 60 Hz as required and at voltages of 6.6 kV or 11 kV. The Onshore Power Station’s modular design will enable it to be adapted and expanded to meet future needs.

Project planning: Implementation in two phases

Phase 1: Establishment of initial supply capacity by 2026
The first phase involves the provision of onshore power supply facilities to serve two ships simultaneously – a main liner (power rating 7.5 MVA) and a feeder ship. A particular focus is on the use of mobile cable management systems (CMS), which add great flexibility to the provision of electricity to ships – regardless of their exact berthing position. The systems’ connection cable (“energy chain”) facilities, each up to 400 m long, are located along the 1300m-long quay and can be positioned as required.

Phase 2: Expansion of capacity by 2030
In the second phase, the capacity of the onshore power station will be expanded, enabling it to simultaneously supply electricity to five ships – it is either one main liner and three feeder vessels or five feeder vessels.

"The project is an important part of our climate neutrality strategy and will ensure the climate-friendly handling of container ships in the port and in future expansions. The tasks were always completed on time by INROS LACKNER, reliably and within budget with the highest quality. We confirm your exceptional commitment to this project and look forward to future projects with you. We also recommend INR0S LACKNER SE for similar services.”   

Jens Dissing, Project Manager, Port of Aarhus

Calculation of CO₂ savings

A key goal of the project is to significantly reduce CO₂ emissions. While moored at the quay, vessels can switch off their diesel generators and use the emission-free onshore power supply. The CO₂ calculation is based on an approach taken by the US Environmental Protection Agency (EPA). The following factors are taken into account:

• The ships’ power requirements (kW)
• Mooring time in hours (h)
• The emission factor of the ship’s fuel (g/kWh)
   

Achievable CO₂ savings

The calculations indicate impressive results:

• Maersk Line: The current CO₂ emissions are 790 tonnes per year. Thanks to the new onshore power supply system, this is expected to fall to 221 tonnes per year by 2027. From 2028, the port will be CO₂-neutral in its operations thanks to the use of 100% green electricity – resulting in 0 tonnes of CO₂ emissions.
• Eimship/RAL: The current CO₂ emissions of 922 tonnes per year will reduce to 0 tonnes by 2028, thanks to the new onshore power supply system.

In the first phase alone, an annual CO₂ saving of 1,712 tonnes will already be achieved by supplying the ships with emission-free electricity.

Status and project progress
The tender processes for the project’s main parts were completed in December 2024, with contracts awarded to the companies PowerCon (for the OPS) and SFT/IGUS (for the CMS). The first phase of the project, which is estimated to cost approximately 12 million euros, has already started and is scheduled to be completed by 2026. We will accompany the project site realisation through to its completion as consultant for the Port of Aarhus. The expansion phase is expected to be implemented by 2030 at the latest and is already contractually tied in as an option.

“The Aarhus onshore power supply project is a good example of the productive, trusting collaboration we always work to achieve with our clients. With a strong focus on the principles of sustainability, we are actively contributing to the decarbonisation of container shipping. It is great to see how our design solutions are helping to make the shipping industry more environmentally friendly and meeting our clients’ needs.”

Tobias Günzl, Department Head, Maritime and Hydraulic Structures

The result: Sustainable port development using modern technologies
The provision of the new onshore power supply system in the Port of Aarhus is a pioneering port development project in terms of sustainability and CO₂ reduction. By using the latest technologies such as modular onshore power stations and flexible cable management systems, environmental impacts can be substantially reduced and future-ready infrastructure created. Inros Lackner SE is supporting this future-oriented project as a reliable partner, helping to make the Port of Aarhus more environmentally friendly and more efficient.