Port of Koper Spent €6.4M on Diesel as Electrification Race Accelerates

Port of Koper's €6.4M Fuel Bill Drives Urgent Electrification Push

Luka Koper, the operator of Slovenia’s sole maritime port, is pushing to electrify its operations as diesel costs climb. Last year the company spent nearly €6.4 million on fuel—equivalent to about 2% of its total operating costs—and expects that figure to rise in 2023. Much of the diesel still powers the heavy machinery that moves containers, cars, and other cargo across the docks.

“Every increase in the price of diesel is a higher cost,” the port acknowledges. To insulate itself, Luka Koper is accelerating a switch to electric drives, particularly for its RTG (rubber‑tyred gantry) cranes, terminal tractors, and forklifts. Two‑thirds of its RTG cranes are already electric, and all new passenger vehicles purchased are battery‑electric—the electrified share of the light‑vehicle fleet now exceeds 30%.

The big‑ticket item, however, is the electrification of the quays. Under an EU directive that takes effect in January 2030, container and passenger ships must be able to plug into shore power while berthed. Luka Koper estimates the necessary grid reinforcement and a new transformer station will cost €100 million, a project it is undertaking together with Slovenia’s transmission system operator ELES.

“A single cruise ship can consume as much electricity overnight as the entire old town of Koper,” President of the Management Board Nevenka Kržan told Forbes Slovenia earlier this year. The port is also expanding its own solar capacity—from 8.2 MW today to 10.5 MW by 2030—which already covers up to 20% of its electricity needs, aiming for a quarter from its own renewables.

Inside the Transition: Crane Electrification, Shore Power, and Grid Challenges

Diesel Dependency: A Single Crane Can Burn 35,000 Litres a Year

The port’s diesel bill is largely driven by mobile cranes, terminal tractors and forklifts. One diesel‑powered RTG crane can consume up to 35,000 litres of fuel annually. With several such units in operation, the aggregate consumption is substantial—hence the decision to electrify two‑thirds of them already. Yet diesel remains essential for many ground‑handling machines, leaving the port exposed to oil‑price swings. At only 2 % of total costs, the financial impact is manageable today, but management clearly sees electrification as a long‑term hedge.

Two in Three RTG Cranes Are Now Electric, But Biggest Guzzlers Remain

All of Luka Koper’s ship‑to‑shore cranes run on electricity, and roughly two‑thirds of its RTG cranes have been converted. The next targets are terminal tractors and heavy forklifts, which are still diesel‑fuelled and account for a large share of the remaining fuel consumption. The port has already tested electric versions of this equipment in live operations, and the first replacements are expected in the coming years. Simultaneously, a port‑wide charging network is being built to support the growing fleet of electric vehicles and machinery.

The €100M Shore Power Mandate: EU’s 2030 Deadline and Grid Bottlenecks

The biggest capital project on the horizon is the €100 million effort to bring shore power to container and cruise berths. The EU’s directive requires that from 2030, vessels at those berths can connect to the on‑shore electricity network, eliminating local emissions and noise from auxiliary engines. Luka Koper, in collaboration with grid operator ELES, must first reinforce the external supply and install a new distribution transformer station. The port’s own solar arrays, which currently cover a fifth of demand (and are set to reach a quarter by 2030), will help but cannot alone meet the massive new load—a cruise ship docked overnight can draw as much power as the historic centre of Koper. This infrastructure, while primarily compliance‑driven, also opens the door to making the port a more attractive call for shipping lines under pressure to decarbonise their supply chains.

What Luka Koper's Transition Means for the Wider Sector

• For port operators: Luka Koper’s data shows that each electric RTG crane can avoid up to 35,000 litres of diesel per year, a benchmark for similar terminals evaluating electrification payback.
• For shipping lines: The 2030 EU mandate for shore power at container and passenger berths means that vessels calling at European ports must be equipped with shore connection capability—or face operational restrictions.
• For infrastructure investors: The port’s €100 million grid upgrade and new transformer station, undertaken in partnership with TSO ELES, indicates the scale of grid reinforcement needed at major ports; similar projects will require coordinated planning with national grid operators.
• For energy managers: Even with 8.2 MW of installed solar (rising to 10.5 MW), the port’s own renewable generation covers only a fifth of current electricity demand; electrified fleets and shore power will sharply increase that demand, requiring additional on‑site or off‑site clean power procurement.