Electric Towing Vehicle Assignment With Charging Requirements

Abstract

One of the most promising ways to reduce emissions at airports is by
towing aircraft instead of taxiing with their main engines, also known
as dispatch towing. One of the airports most involved with this concept
is Amsterdam Airport Schiphol (AMS), as it has an emission-free target
for 2030. One of the challenges with this concept is to optimize the
assignment of Electric Towing Vehicles (ETVs) to maximize the
effectiveness. The developed model can assign ETVs to flights and
charging moments for the tactical planning phase, minimizing fuel
consumption, charging cost and number of chargers. The results of the
model are illustrated for two peak days at AMS. Both a small and large
fleet of ETVs are assigned on both days for a northbound and southbound
runway operation. The total fuel cost savings for the small fleet are
25% and 45% for the large fleet, which are similar on both days. On both
days, outbound flights are the preferred direction to be towed due to
the distribution of towing times. The savings per ETV are highest for a
small fleet and decrease until all flights are towed. Furthermore, the
load on the charging infrastructure at AMS for different fleet sizes
shows what average and peak power can be expected. It is shown that ETV
utilization and computation time can be improved significantly, by
implementing costs on time and introducing utilization and symmetry
constraints. However, with the important limitation that these
improvements are observed only for small planning horizons. Finally, a
sensitivity analysis on charging power showed that increasing the
charging rate has a positive impact on both fuel cost savings and the
minimum number of chargers required. In conclusion, this study shows the
potential impact of dispatch towing at AMS in terms of fuel savings,
charging infrastructure and operational challenges.