On the path to 100% sustainable logistics

A smooth transition to an all-electric delivery fleet 

In principle, the conversion of Swiss Post's delivery fleet to purely electric vehicles (EVs) seems simple: scrap old vehicles, purchase new ones and install charge points. However, it is not quite that simple. Swiss Post's large fleets need a place to charge their batteries during peak times in the early evening and overnight. The simultaneous charging sessions result in high peak loads, which the infrastructure at the sites is largely unable to cope with as it was not designed for such use. As a result, most locations do not have enough capacity for all vehicles to charge at the same time. Uncontrolled charging of the fleet would therefore quickly lead to overloads, which could then restrict operations at the site. 

Dynamic load management ensures operational continuity

gridX’s energy management system (EMS) controls loads in real time. The Grid Protector module is used to ensure that the capacity of the grid connection point (GCP) and all sub-distributions is not exceeded. This prevents overloads and ensures smooth operation. In addition, dynamic load management ensures that charging processes are not unnecessarily throttled. If, for example, all vehicles return to the site at around 03:00 p.m., the EMS uses dynamic load management to control charging processes in real time, according to the respective building load. The fast reaction time of the control (approximately 200 milliseconds), ensures overloads are effectively prevented. For example, the EMS shifts charging sessions into the night and thus equalizes the number of simultaneous charging processes. The intelligent algorithms can initiate various types of throttling of the charging speed, enabling the use of various intelligent charging strategies at the postal locations. This means it is possible to charge the EVs one after the other so that all parts of the fleet are equally charged by the end of the night. Thanks to the locally installed IoT gateway, the gridBox, which gives the EMS very low latency, gridX's energy management also ensures that charging is not impaired even in the event of temporary internet outages. The system also guarantees that operations are not restricted the following day – a significant advantage over a purely cloud-based EMS.

Complexity poses no problem

The energy supply at a Swiss Post site is extremely complex. Many energy-consuming devices are naturally present on site – simply due to the logistics provider's operations. The buildings and all the loads they contain represent the so-called “base load”, which is generally a fairly uniform load that constantly affects the GCP and cannot be flexibly adjusted or shifted. These loads, such as the mail sorting machine, often cannot be operated with throttled capacity. Alongside this there are fluctuating flexible loads that vary in terms of the stress they place on the GCP, such as the charge points for electric delivery vehicles. At large and complex locations, like most large postal distribution centers, the local energy infrastructure typically consists of various control circuits with different sub-distribution boards. With particularly high and flexible loads, various sub-distributions are susceptible to overloads at many points in the local energy infrastructure, as the limit of the grid connection and the sub-distributions must not be exceeded. 

XENON controls and optimizes charging cycles 

By using smart energy management from gridX, Swiss Post can efficiently operate large electric delivery fleets and complex charging infrastructure at a wide range of locations without jeopardizing regular operations due to overloads. In addition, the company avoids costly and time-consuming extensions to the GCPs at many locations, while still providing sufficient charging capacity for its own fleet. Since the start of the collaboration and up to October 2023, the solution has been installed at nine locations and already controls over 70,000 charging cycles at 300 charging points.

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