The short answer
Once ground support equipment goes electric, the charging schedule competes with the turn plan for the same hours and the same power supply.
The fix is to schedule charging against both: which unit is needed for which turn, its state of charge, and the site’s power limit.
The data that makes this work — utilisation, charge state and turn times — is the same data you need for the funding case and the next electrical upgrade.
The new problem on the ramp
A diesel tug refuels in minutes whenever someone gets round to it. An electric one needs hours on a charger, has less range on a cold morning, and draws from the same electrical supply as every other charger on the site. Half-electrify a fleet and you have a scheduling problem nobody had before: the unit that is needed for the first wave may be the one that was plugged in last.
Three constraints to plan against
- The turn plan. Which equipment each turn needs, and when. This sets when each unit must be charged and available.
- State of charge. How much each unit has left, and how quickly it recharges. Cold weather reduces usable battery capacity, so winter plans need margin.
- The site’s power limit. Chargers draw from a supply with a fixed capacity, and many commercial electricity tariffs charge for the peak demand, not just the energy used. Everything plugged in at once is the expensive way to charge.
Smart charging in practice
Smart charging means deciding which unit charges, when and at what rate, instead of charging everything the moment it is plugged in. Units needed first get priority. Charging is spread into the gaps between waves to stay under the site limit and flatten the peak. Short opportunity charges between turns top up units that will be needed again soon.
It only works with real data: utilisation from telematics, charge state from the chargers or the equipment, and the turn plan itself. Without them, charging is scheduled by habit, and the peak is set by accident.
The funding case
At commercial service airports in areas that don’t meet federal air quality standards, the FAA’s Voluntary Airport Low Emissions (VALE) programme lets sponsors use Airport Improvement Program funds and Passenger Facility Charges for projects such as electric GSE and its charging infrastructure. Any funding case, and any conversation with the utility about a bigger supply, goes better with measured utilisation and load data than with estimates.
Where to start
Measure before you buy. A few weeks of utilisation and turn-time data from the existing fleet shows how many units each wave really needs, which ones sit idle, and what peak charging load the electric fleet will create. That tells you how many chargers you need, where, and whether the site supply is the real constraint.