Fleet energy optimisation is the ongoing process of reducing the cost, peak demand, and carbon impact of fleet charging while maintaining (or improving) vehicle readiness. It uses data + control (CPMS/EMS) to decide when to charge, at what power, and using which energy sources, across depots and other fleet locations.
What fleet energy optimisation means in practice
Optimisation typically targets three outcomes at the same time:
– Readiness: vehicles meet target SoC/kWh by departure time
– Cost: lower all-in €/kWh and €/km (energy + demand charges + charging OPEX)
– Grid fit: keep peak kW within site limits to avoid upgrades and outages
– Optional: Carbon: shift charging to lower-carbon hours and document electricity sourcing
The main optimisation levers
1) Peak shaving and power caps (protect the site)
– Set a hard site power cap (kW) and allocate power across chargers dynamically
– Prevent “everyone charges at once” return-to-depot peaks
– Reduce demand charges/capacity fees where applicable
– Avoid breaker trips and thermal stress in switchgear
2) Tariff-aware scheduling (charge when it’s cheaper)
– Use time-of-use windows and/or dynamic prices to shift load
– Charge “just-in-time” rather than immediately
– Keep a catch-up buffer before departures for late arrivals and exceptions
3) Departure-time optimisation (readiness-first)
– Assign each vehicle an energy target by a deadline
– Prioritize: earliest departure, lowest SoC, critical routes
– Minimize simultaneous charging to reduce peak while meeting deadlines
4) Charger utilisation and right-sizing
– Increase vehicles-per-charger safely using scheduling + rotation rules
– Avoid overbuying chargers and oversizing grid upgrades too early
– Use phased expansion: add bays/conduits early, add chargers/power later
5) On-site energy assets (PV/BESS integration)
– PV: prioritize charging when solar is available (where operationally possible)
– BESS: store energy off-peak or PV and discharge during peak charging periods
– Use BESS for peak shaving and resilience, not only “energy arbitrage”
6) Demand response / flexibility
– Temporarily reduce charging during grid events or high-price periods
– Keep readiness protected with priority tiers and minimum SoC floors
– Potential additional revenue or reduced network charges (market-dependent)
What you need to optimise effectively (data + controls)
Data inputs
– Charger sessions: kWh, timestamps, charger/site IDs, vehicle mapping
– Depot metering: interval kW/kWh at mains and key sub-boards
– Fleet plan: arrival/departure times, route criticality, target SoC/kWh
– Tariffs: TOU periods, demand charge rules, capacity fees
– Optional: PV generation forecast, BESS state, hourly carbon factors
Control capabilities
– Per-charger or per-group active power throttling
– A hard site cap and rules-based priorities
– Scheduling engine (deadline-based + tariff weighting)
– Exceptions and overrides (urgent vehicle, missed plug-in)
KPIs to prove optimisation is working
– All-in cost per kWh delivered at depot (energy + software + service)
– Peak kW and peak duration (before vs after optimisation)
– Readiness rate (% vehicles hitting target by departure)
– Public charging fallback rate (should reduce)
– kWh shifted to off-peak (or to PV hours)
– Charger utilisation: sessions/day, charging hours, vehicles per charger
Common optimisation playbooks (quick wins)
– Implement a site cap + “no immediate charging” rule during evening peak
– Use two waves: charge early departures first, then everyone else off-peak
– Create priority tiers: critical routes, normal routes, flexible vehicles
– Fix “non-charging plugged-in” issues with alerts and driver workflow
– Standardize cable/bay rules to prevent blocked chargers and idle occupation
Common mistakes to avoid
– Optimising cost while ignoring readiness (missed departures)
– Only tracking kWh, not peak kW (demand charges appear later)
– No ownership for network/firewall issues, breaking scheduling controls
– Weak vehicle-session mapping, making cost allocation and reporting unreliable
– Overcomplicating early—start with caps + deadlines, then refine
Related glossary terms
Fleet energy management
Fleet charging scheduling
Dynamic load management
Active power throttling
Demand charges
Time-of-use tariffs
Fleet demand response