Powering the Future: Electrification as the New Normal for Straddle Carrier Operations

2 Background, trends and investment drivers

The global container handling industry is at a turning point: electrification is no longer a distant ambition, but a critical step toward achieving sustainable, resilient and cost-efficient operations. As ports and terminals face mounting regulatory pressures, stakeholder expectations and the urgent need to cut emissions, electrification offers a clear pathway to both environmental responsibility and long-term competitiveness.

This white paper is intended to provide a general overview of the current state of container terminal electrification, when considered from the point of view of horizontal transportation equipment. The paper focuses particularly on charging strategies for manually operated and automated straddle carriers, but many of the basic principles will be applicable to other types of container handling equipment as well. Since quay and yard cranes have already been mostly electrically powered for many years, they are omitted from the scope of this discussion.

The publication builds on the foundations laid in Kalmar’s earlier white papers including Road to Zero, outlining the industry’s decarbonisation journey, and Designing Future-Proof Terminals, which explored strategies for operational adaptability in a changing world.

Industry trends in terminal electrification

At the time of writing (mid-2026), the electrification of straddle carriers has moved from pilot projects to commercially credible full-scale deployments. Advances in battery and charging solutions, growing product offerings, and expanding public funding for zero-emission infrastructure are converging to reduce the technical and business risk, enabling terminal operators to begin transitioning to electric fleets with minimal operational impact.

Over the last few years, electric straddle carriers have decisively become a realistic production solution. Forward-looking terminals such as DP World London Gateway that initially began their electrification journeys with small-scale pilot projects have now found that electric straddle carrier fleets have provided them with a compelling business case and a clear roadmap for the future.

At the same time, multiple charging and battery strategies including depot, opportunity and mixed-mode smart charging are seeking and finding their place in terminal-level solutions. Decisions made today must balance capital costs, grid capacity and operational needs, while fitting in with the terminal’s long-term fleet renewal strategy.

Driving down TCO with electric straddle carriers

The total cost of ownership makes battery-electric straddle carrier operations an increasingly attractive alternative to traditional hybrid or diesel-electric solutions. This is driven by a confluence of market momentum and new technical enablers.

3 Charging strategies

A key consideration for straddle carrier electrification is the choice of charging strategy for the machines. Straddle carrier operations at container terminals have been generally designed for traditional diesel-electric or hybrid machines that enable a full shift’s operation without refuelling.

Battery-electric technology introduces an alternative operating profile that typically features a maximum operating time of around 8 hours, so charging needs to be integrated into continuous terminal operations. As a result, any battery-electric straddle carrier solution will need to select a charging strategy that strikes the optimum balance between total cost of ownership, fleet performance and operational constraints.

The choice of charging strategy can easily be perceived as merely a technical choice between several alternative solutions, but it is a much broader question that ties into the overall strategy, operating environment and business goals of the terminal. However, in the early stages of piloting, the exact choice of charging strategy is not critical, and terminals can easily begin exploring the benefits of electrification while refining their charging concept based on the real-world experience they have gained.

At the time of writing, there are three main charging strategies that are relevant for straddle carriers. These are depot charging, rotation charging and opportunity charging, each of which will be summarised briefly below.

It is important to note that the choice of the best charging strategy will depend greatly on the individual operational profile of the terminal. Moreover, the strategies outlined below are not mutually exclusive, and the optimum strategy for a terminal may well involve a combination of elements from multiple strategies.

All the charging strategies are relevant for both manually operated and automated straddle carrier terminals; however, certain strategies may be better suited for one or the other. For example, automated terminals will be able to realise the full potential of opportunity charging better than manual operations, since the automation system can re-assign machine jobs and charging tasks significantly faster than would be possible with manually driven straddle carriers.

Depot charging

In many ways, depot charging can be considered the theoretically optimum way of charging an electric straddle carrier fleet. In this strategy, charging takes place during pre-planned times such as lunch breaks and shift changes. As charging speeds increase in the future, the time needed for charging the machine will decrease correspondingly.

In practice, the feasibility of depot charging depends greatly on the operational concept and work shift pattern of the terminal. For a fleet of straddle carriers, the technically ideal solution would be to stagger the charging breaks so that all the machines are not charging at the same time, in order to even out the peak loads on the electrical grid. However, this is often not possible due to pre-existing work shift arrangements or other operational patterns, but depending on the specifics of the terminal, depot charging may offer a simple and easy-to-realise charging strategy that requires minimal changes to existing terminal infrastructure and operational processes.

Charging with CCS/MCS during the mandated operator breaks¹

1) Modelled with CCS charging and 50 kWh/h average consumption. Charging speed will vary depending on the charging method, with MCS enabling faster charging than CCS.

Rotation charging

Rotation charging is arguably the simplest of the charging strategies, and it also provides the most stable load profile on the power grid. The system is compatible with 24/7 operations, requires no changes to existing shift patterns and results in minimal equipment downtime due to charging.

The principal trade-off is that more machines are needed when compared to a traditional fleet of given size. The exact numbers will vary depending on the specifics of the terminal operation, but typical calculations for real-world terminals indicate that 10–20% additional machines will be required.

For a terminal operator, this is a nontrivial increase in required capital expenditures; however, it is important to note that each machine in the larger fleet will accrue proportionately fewer operating hours over a given period, so the operating life of the machines should be commensurately longer, at least partially offsetting the larger capital investment over time.

The larger required fleet size also creates additional demands on the terminal beyond the actual charging of the machines. Parking space and service facilities must be available for the extra straddle carriers, and the driving distance from the charging location to the operational area must be manageable. As a result, rotation charging is likely to be most practical for terminals with medium-sized straddle carrier fleets.

Charging with CCS/MCS according to the rotation schedule²

2) The illustration of the charging cycle has been modelled with CCS charging and 50 kWh average consumption. Charging speed will vary depending on the charging method, with MCS enabling faster charging than CCS.

Opportunity charging

All manual and automated straddle carrier operations inevitably include moments in which the machines are not engaged in an active work task. The idea of fast opportunity charging is to use these waiting times to charge the machine in short and frequent charging sessions with charging stations that are placed at easily accessed locations in the operating area. For this reason, opportunity charging may also be attractive to terminals that have a particularly long driving distance from the equipment depot to the operating area.

Opportunity charging will, by default, require a hands-free charging interface that does not need an operator to connect and disconnect the charging connector. Kalmar’s pantograph-based FastCharge^TM interface already enables rapid charging at megawatt-level power, while an automated version of the MCS interface is in development at the time of writing.

The principal challenge of opportunity charging is that it requires more sophisticated planning and coordination than strategies based around centralised charging depots. In practice, charging optimisation software is needed to coordinate charging across the fleet. By making fleet-wide charging decisions, the software maximises charging station utilisation and minimises equipment waiting times beyond what is possible with manual planning or individual machine-level decision-making.

Examples of Kalmar solutions for this purpose include the Kalmar One Scheduler, which provides job scheduling, dispatching and charging task optimisation in automated terminals, and Kalmar SmartCharge, which automatically assigns charging tasks to the equipment operator at manual terminals. Both solutions are designed to avoid queues at charging stations and ensure the highest utilisation rates at equipment charging points.

It’s also important to note that for the purposes of charge scheduling, the solution does not necessarily need to wait for a moment where the machine is fully idle; instead, it can direct it to charge at the moment that is calculated to result in the least loss of productivity at the level of the entire system. Automated straddle carrier terminals hold an advantage here, as the automation system can schedule and re-schedule jobs and charging tasks for the automated machines at a pace that is far beyond the capacity (or patience) of human operators to handle.

Despite its added complexity, smart opportunity charging arguably holds the greatest potential for optimising electric straddle carrier operations with productivity that is equal to or potentially even greater than that of traditional hybrid or diesel-electric machines.

Charging with FastCharge/MCS during the operation³

3) Modelled with Kalmar FastCharge and 50 kW/h average consumption. Illustration of the charging cycle. Total charging time 90 minutes.

Other charging concepts

As an alternative to the above strategies, battery swapping (replacing a discharged battery pack with a charged pack via automated or manual swapping stations) has been used for some types of electric equipment, most notably Automated Guided Vehicles (AGVs). In principle, battery swapping offers several advantages including minimal downtime from charging and smaller onboard batteries. However, as the system relies on centralised swapping stations, potential disruptions (e.g. technical malfunctions or safety incidents) could impact a significant portion of the fleet, which may require consideration of redundancy measures. As no battery swapping solutions are currently available for straddle carriers, the concept is not explored further in this publication.

Mixed charging strategies

It is important to note that the charging strategies outlined above are not mutually exclusive. In fact, drawing on real-world experience from customer sites around the world, as well as simulation insights using real operational data, the authors of this paper consider that for most electric straddle carrier terminals, the optimum charging solution will involve a mix of strategies. At the time of writing, the mixed strategy that appears to hold the most promise is a combination of depot and opportunity charging.

Any plan for charging electric straddle carriers must also consider the total picture of energy usage at the terminal. Depending on the type of equipment, some or all of the charging infrastructure for straddle carriers may be utilised for other types of terminal equipment as well. For some terminal operators, the grid loads imposed by the simultaneous charging of multiple electric straddle carriers may pose a significant challenge; for others, the additional peak loads might fade into insignificance alongside ongoing initiatives for providing shore power for large container vessels.

Megawatt charging: The game changer

4 The electrification journey

Electrifying a straddle carrier fleet is not a single decision – it is a journey. At Kalmar, electrification is planned with a structured process designed to reduce uncertainty, maximise return on investment, and ensure that the final solution is both technically and operationally robust.

The planning part of the journey consists of four key phases: Investigate, Qualify, Demonstrate and Re-Qualify.

Simulation vs. Emulation – what’s the difference?

The outcome

The result of this iterative planning process is a fully validated electrification roadmap that minimises risk, optimises investments, and accelerates the transition to cleaner, smarter and more efficient straddle carrier operations.

Electrification is rapidly emerging as one of the most impactful pathways toward sustainable and future-ready container terminal operations. Among the different equipment types in a terminal, straddle carriers represent a high-value target for electrification due to their intensive use, fuel consumption (for diesel and hybrid machines) and their central role in horizontal transport. Moving from diesel to electric straddle carriers reduces both operating costs and the terminal’s environmental footprint, while improving predictability and compliance with tightening emission regulations.

However, electrification is not a one-size-fits-all decision. Terminals must weigh the technical, financial, and operational implications of retrofitting existing straddle carriers versus investing in new electric units, while also aligning with broader fleet renewal and lifecycle planning strategies. Here, simulation and emulation tools provide crucial insights by modelling different deployment scenarios, charging strategies and total cost of ownership (TCO) impact over time.

These tools are equally valuable for automated operations, where the interaction between fleet management systems and charging behaviour must be seamless, and for manual operations, where variability in driving patterns and break schedules influences energy use. In both cases, simulation and emulation reduce risk, accelerate learning, and ensure that electrification strategies are not only technically feasible but also operationally resilient.

Emission reduction potential of the electric straddle carrier

One of the most significant benefits of electrifying straddle carrier operations is the potential for substantial emission reductions across the equipment lifecycle.

To better understand the environmental impact of different powertrain technologies, Life Cycle Assessments (LCAs) have been conducted for Kalmar electric and hybrid straddle carriers as well as their diesel counterparts. These assessments evaluate the total CO2 impact of the equipment throughout its lifecycle, including raw materials, manufacturing, transportation, energy consumption during operation, and service and maintenance requirements.

Potential lifetime emission reductions of hybrid and electric straddle carriers

5 Start small, start now

Electrifying a straddle carrier operation requires careful planning and validation; it goes far beyond replacing diesel-powered machines with battery-electric ones. Electrification is a long journey that involves finding the optimum balance between multiple factors such as operational performance, energy demand, charging infrastructure and long-term fleet renewal.

However, the good news for terminal operators is that piloting is generally very easy and can be begun even if a fully realised long-term electrification strategy is not yet available. In fact, it can be argued that in today’s business and technology landscape, any terminal will benefit from testing electric straddle carriers in order to prepare for the (inevitably electric) future.

For most terminals, the key question of which charging strategy to adopt does not really need to be answered in the beginning. Unless the terminal has a “hot seat” operation or unusually strict electricity grid limitations, it will almost always be possible to convert to electric incrementally over the next 10 to 15 years as the existing fleet is renewed.

In an electrification pilot, the key considerations will be getting used to the new technology, and understanding the use of the machines from the perspectives of operators, technicians and business planners. For small-scale pilots involving a few machines, depot charging (possibly complemented by faster megawatt charging) may offer the simplest way to integrate the electric machines into the existing operation.

Before committing to large-scale investments in electric straddle carriers, terminals need confidence that the chosen operational concept – fleet size, charging strategy, and infrastructure layout – will perform reliably under real conditions. Through simulation, planners can evaluate key factors such as duty cycles, energy demand, charging windows, and throughput impacts, while emulation allows integration of actual control systems and automation logic to verify performance in a realistic environment.

Real-world feedback from terminals that have begun their electrification journey with small-scale pilots indicates that in most cases, the electric machines can be slotted into the existing operation with practically zero effect on operational planning. These hands-on experiences serve as the ideal basis on which to develop the full electrification roadmap for the terminal – and from which to take next practical steps toward that envisioned future.

Appendix: Understanding the TCO of electric straddle carriers

Benefits	Challenges
Lower operating costs: Significant reduction in fuel and maintenance costs compared to diesel units	Higher upfront investment: Both retrofits and new units require significant capital, especially when combined with charging infrastructure
Emission reductions: Immediate cut in local pollutants and CO2, supporting sustainability targets and regulatory compliance	Infrastructure dependency: Requires careful planning for power supply, grid upgrades and charging points
Energy price stability: Electricity prices are generally more stable and predictable than fossil fuels	Operational adaptation: Charging cycles and range limitations may necessitate changes in shift planning or workflows
Enhanced efficiency through digitalisation: Electric fleets integrate seamlessly with energy management systems, enabling smart charging and load balancing	Retrofit technology maturity: Retrofits may have shorter lifespans or performance constraints compared to new electric machines
Future-proofing: Prepares terminals for long-term decarbonisation strategies and stakeholder demands for greener logistics.	Residual value uncertainty: Market values for retrofitted units may be less predictable than for factory-built electric machines

About the authors

Marko Hopeaharju

Director, Innovation and Product Management, Kalmar

Marko Hopeaharju is Director, Innovation and Product Management at Kalmar and has worked with the company for over 30 years. He brings to his role extensive experience in business and product management, R&D and engineering, automation and integration, sales with global customers and electrification. Throughout his career, Marko has held various management roles driving the growth of container handling equipment, automation solutions and sustainable innovations in a continuously evolving container handling industry.

Sami Yli-Äyhö

Senior Manager, Product Management, Kalmar

Sami Yli-Äyhö is Senior Manager, Product Management at Kalmar and has been with the company for almost 20 years. He is an experienced R&D leader with a strong track record in the machinery industry, skilled in engineering management, project and program management, and product development. Throughout his career, Sami has successfully led teams and projects driving innovation and development in Kalmar’s equipment and solutions.

Mette Kjems Bærentzen

Director of Decarbonisation, Kalmar

Mette Kjems Bærentzen is Director of Decarbonisation at Kalmar, where she leads the company’s efforts to reduce emissions across Kalmar’s products and global operations. She supports the implementation of low-carbon technologies while building cross-industry partnerships that help ports and terminals accelerate their transition toward more sustainable operations.

Kivi Siik

Sales and Business Development Specialist, Terminal Design Services, Kalmar

Kivi Siik is Sales and Business Development Specialist at Kalmar. As part of the Terminal Design Services team, he supports both brownfield and greenfield terminal modernisation projects, many of which focus on electrification and automation. With a background in business, Kivi focuses on helping customers identify the financially optimal solution for their terminal modernisation.

Disclaimers
The goal of this paper is to provide a brief overview of lithium-ion battery technology for a non-technical professional readership in the logistics and cargo handling industries. The white paper represents the opinions of the authors, and is the product of professional research. Kalmar can not be held liable for how the information in the white paper is used. The information included was current at the time of writing (January 2026).