Simulation Study of Charging Infrastructure for Battery Electric Trucks at Forest Industry Site

Sammanfattning

Electrification of heavy-duty road transportation is an important step toward reaching Sweden's climate goals. One commonly mentioned approach is the use of battery electric trucks (BETs) using plug-in charging. The forestry industry in Sweden accounts for a significant portion of truck transportation, positioning the industry as an interesting area of study. One question is where charging infrastructure should be placed, where some alternatives are at roadside rest areas, at home depots, or at delivery sites. This study implements a simulation environment based on the daily flow of 200 incoming timber trucks at a Swedish paper mill to study the amount of energy supplied to BETs as well as the power demand and utilization rate throughout a day when two charger layouts are introduced. One scenario implements a new area at the site where charging can take place before or after trucks complete their delivery. The other scenario implements chargers at the existing unloading area within the log yard. With a separate charging area, power peaks are most prevalent when trucks take their rest periods and later in shifts when state of charge (SOC) levels are lower. Low-use periods occur before trucks take their mandatory rest stops. Going above four chargers does not provide a significant charging benefit unless there is a high degree of BETs in the system. Considerable utilization can be possible with fewer chargers. When charging occurs during unloading, the power demand is dependent on the traffic of BETs through the site since charging only occurs while unloading. This means that a high ratio of BETs is necessary for solid utilization rates. It also means that utilization suffers at times during the day with lower arrival frequencies and when trucks have high SOC such as the start of shift or after charging breaks. A further limitation is that this scenario would require new routines for unloading to account for the new charging infrastructure within the existing system.