Slovenia has demonstrated that electric-vehicle charging can be managed as a flexible electricity portfolio, rather than treated simply as an additional source of power demand. The approach could create new business opportunities for fleet operators, aggregators, electricity suppliers and charging-platform companies.
A two-month demonstration in Ljubljana involving Avant Car and Kolektor sETup used automated charging schedules to shift EV consumption towards periods with lower electricity prices while ensuring that vehicles still received the energy required for their planned journeys.
The trial covered six charging stations and used day-ahead electricity-price signals to determine when vehicles should charge. Before optimisation, actual charging costs were 18.9% higher than the theoretical least-cost scenario. During the demonstration, the gap fell to 5.99%, representing an improvement of approximately 68% in matching charging activity with the cheapest available periods.
The commercial importance of the results goes beyond reducing electricity bills. EV fleets combine three characteristics that make them increasingly valuable to power systems: large electricity demand, predictable connection periods and flexibility over when charging takes place.
An EV may require a specific amount of electricity before its next trip, but there is usually no need for every kilowatt-hour to be delivered immediately after the vehicle is connected. The period between arrival and departure creates a flexibility window that software can optimise.
A fleet-management platform can determine which vehicles require immediate charging, which can wait and how much total electricity demand can be shifted between different market periods. Charging consequently becomes an optimisation problem, rather than a simple transaction between a vehicle and a charging point.
For fleet operators, the immediate benefit is lower electricity expenditure. For aggregators and suppliers, the larger opportunity comes from combining hundreds or thousands of chargers into a controllable portfolio.
A fleet containing hundreds of vehicles could potentially shift several megawatts of electricity demand between different periods without affecting the transport service provided to customers. That makes EV charging relevant not only for electricity procurement but also for demand response, balancing services and local flexibility markets.
The Slovenian demonstration focused primarily on day-ahead price optimisation, shifting charging towards less expensive periods, including overnight hours. The results showed that automated scheduling can significantly narrow the difference between actual charging costs and the theoretical optimum.
However, large-scale deployment introduces another challenge. If thousands of vehicles receive the same price signal and automatically shift charging into the same low-price period, the resulting concentration of demand could create a new peak for the electricity network.
What is economically optimal for an individual consumer is therefore not necessarily optimal for the grid. The next generation of smart-charging systems will need to move beyond simple time-of-use pricing.
Charging algorithms could increasingly combine at least two signals: the wholesale electricity price and the physical condition of the local network. A third signal could come from balancing and flexibility markets.
An EV fleet could then respond differently depending on where its flexibility has the greatest value. During one period, it could charge more aggressively because wholesale electricity is inexpensive. At another time, it could reduce charging to help relieve a distribution constraint. It could also adjust consumption when a system operator requires additional balancing flexibility.
This effectively turns a charging portfolio into a virtual power-system asset.
The business model is particularly relevant for centrally managed fleets. Car-sharing companies, delivery operators, municipal fleets, taxi companies, corporate vehicles, buses and logistics operators generally have more predictable information about vehicle schedules than individual residential users.
Fleet managers may know which vehicles need to depart at 06:00, which will remain parked until midday and how much energy each vehicle requires. An optimisation platform can use those constraints to calculate the cheapest or most commercially valuable charging schedule.
The physical charging station is therefore becoming only one component of the overall service. Increasingly, value could shift towards the software layer that manages thousands of chargers.
This creates opportunities for companies specialising in fleet-management systems, aggregation, automated electricity trading, charging optimisation and market access.
It could also influence how businesses procure charging infrastructure. Instead of evaluating chargers primarily according to hardware price and maximum charging capacity, fleet operators may increasingly assess whether a platform can reduce electricity costs and generate additional flexibility revenue over the lifetime of the equipment.
Vehicle-to-grid technology could eventually expand the opportunity by allowing electricity to flow back from EV batteries into the grid. However, bidirectional charging is not required for the first stage of the market.
Simply controlling when vehicles consume electricity already provides a substantial source of flexibility. This makes smart charging commercially relevant well before large-scale V2G deployment becomes widespread.
Slovenia’s demonstration remains small compared with the scale required for a fully developed national flexibility market. Nevertheless, the results show that automated charging of shared EV fleets can materially reduce the gap between actual and optimal electricity costs under real operating conditions.
The next challenge is scaling the model. As EV adoption accelerates, unmanaged charging could become an additional source of peak electricity demand. Managed fleets offer the opposite possibility: electric vehicles could become one of the largest controllable sources of electricity consumption.
For electricity companies, aggregators and fleet operators, this changes the commercial proposition. The value of an EV fleet may increasingly depend not only on the kilometres its vehicles travel, but also on the flexibility they provide during the hours when they are parked.
