Myth #1: Electric straddle carriers reduce operational efficiency and reliability

"To put it very simply, no," says Aki Heikkinen, Sales Development Lead, AMEA Horizontal Transportation, Kalmar. "A straddle carrier operation will always include a certain amount of time in which the machines are waiting for another system such as an STS crane to complete its job. With today's battery and charging technology, it is perfectly possible to utilize this time for charging without any appreciable decrease in overall efficiency, as long as the charging times are designed into the operation."

The charging technology that is currently available for Kalmar Electric Straddle Carriers is the most powerful in the market, enabling rapid charging at up to 600 kW. Kalmar offers two battery technologies: High Energy batteries enable electric straddle carriers to operate for 4 to 7 hours with a charging time of approximately 35 minutes from an empty to full battery, while High Power batteries provide continuous operation times of up to 70 minutes with a charging time of only 5 minutes. Both types of batteries can be charged with the Kalmar FastCharge system as well as a standard CCS/CCS2 charging interface.

"Electric machines do need to be charged regularly, but many terminal operators are not aware that charging a battery-powered straddle carrier no longer requires the machine to be offline for several hours," says Timo Alho, Director, Product Management & Business Development, Kalmar. "Moreover, the next generations of charging systems will be even more powerful, so the times needed for charging will only decrease in the future. Of course, maximum operating times will vary depending on the specifics of the operation, but the same holds for diesel-electric and hybrid machines."

The next generations of charging systems will be even more powerful, so the times needed for charging will only decrease in the future

Fast charging, smart operations

It is true that battery-powered operations may require more planning and time management to sustain consistent productivity throughout shifts. However, centralized optimization and intelligent charge management can not only ensure the continuous efficiency of operations, but also allocate charging times to each machine so that overall energy usage is optimised. Kalmar's charging solutions and battery technologies are fully cross-compatible for maximum flexibility.

"The optimum charging strategy and battery choice will depend on the specific details of the operation, so there is no 'one size fits all' solution," notes Sami Yli-Äyhö, Senior Manager, Product Management Horizontal Transportation, Kalmar. "For a terminal that operates with regular breaks in its daily schedule, High Energy batteries charged with the traditional CCS charge interface could be the best solution, whereas a 'hot seat' operation with continuous shifts of several hours might opt for High Power batteries and top-up opportunity charging with the FastCharge interface."

"Electrification will always require some changes in the operation of the terminal," adds Timo Alho. "At the most basic level, a smart charging strategy ensures that the charge level of the individual machines is managed in such a way that they will not all reach low battery levels at the same time. This automated charge planning and scheduling needs to be done as part of the overall optimisation of the operation, and Kalmar can offer the software to support it."

Fewer moving parts

Finally, with regards to the efficiency of electric straddle carrier fleets, electric vehicles and equipment are often thought to be less reliable compared to diesel-powered options. Sami Yli-Äyhö is quick to debunk this myth as well.

"For traditional diesel-electric or hybrid machines, the diesel engine is, by far, the subsystem requiring the most servicing, and the higher the emission standard of the engine, the more complex the maintenance. It's worth noting that our straddle carriers have basically been electrically driven already for over two decades, so for battery-powered machines, the only change is that we are replacing the diesel engine with a battery pack. With the elimination of the diesel power unit, the machines will be, if anything, even more reliable, while requiring less scheduled maintenance."

The batteries on Kalmar Straddle Carriers are essentially maintenance-free and designed to last for the lifetime of the machine, whereas a diesel engine would generally be replaced at least once during the service life of the machine.

"To summarize, not only do battery-powered straddle carriers enable operational efficiency that is at least comparable to hybrid or diesel-electric machines, but also they offer significantly lower maintenance costs due to the simplified all-electric design," says Timo Alho. "These findings have been conclusively confirmed by our terminal customers running battery-powered straddles as part of their regular operations."

To summarize, not only do battery-powered straddle carriers enable operational efficiency that is at least comparable to hybrid or diesel-electric machines, but also they offer significantly lower maintenance costs due to the simplified all-electric design

Stay tuned for the next episode in the series: How does the total cost of ownership of electric straddle carriers compare to hybrid or diesel-powered machines?