EV charging infrastructure: power delivery, reliability and the smart grid

CSL Group’s second-edition white paper follows the charging service from the grid connection and the charger to the management platform, payment services and the wider energy system. At each step, it sets out what a site specification should state.

Six 350 kW chargers running together at full output deliver 2.1 MW to vehicles and draw more than that from the grid. At depots and en-route hubs, the available grid capacity can constrain how much charging power the site delivers at once.

Smart charging shares the capacity the connection allows, and still has to give each vehicle its energy before it leaves. The schedule depends on data that the vehicle, the site and the energy supplier send over communications links.

Each part of a charging service needs its own evidence, and the paper takes them in turn.

• Power delivery and smart charging. How grid limits, storage, vehicle demand and departure schedules set charging rates at destinations, public hubs and depots, and what vehicle-to-grid operation needs.
• Charging reliability. Why an ‘available’ status is not the same as a successful session, and how authorisation, payment, roaming and monitoring depend on communications.
• What connectivity downtime puts at risk. Illustrative driver payments at risk for chargers from 7 kW to 150 kW, and the larger exposure when many chargers share a network dependency that fails.
• Standards and testing. How OCPP 2.1 edition 2, the IEC 63584 series, OCPI and the 2026 amendment to ISO 15118-20 affect charging functions, including bidirectional operation, and why each function still needs interoperability testing.

A multi-network SIM with one operator’s profile can use several radio networks, but its traffic depends on that operator’s core. If that shared core fails, switching radio networks alone cannot bypass it. A second path through an independent operator core provides an alternative route for restoring communications.

Local switching allows the equipment to respond without relying on an instruction from the platform reaching it through the failed connection.

CSL Group’s managed connectivity uses CSL DualCore® architecture: independent operator cores, switching inside the equipment and private encrypted routing on both paths. CSL delivers it in two ways:

• In compatible chargers, rSIM® technology switches between two independent profiles held on the charger’s SIM.
• A CSL DualSIM® Router configured for core independence provides resilient connectivity within an individual charger or across a multi-charger site.

At larger hubs and depots, CSL Outpost combines up to four active mobile connections into one managed link, with satellite and fixed line where needed.

Faults in the electricity supply, the charger or the payment platform are resolved in their own layers. Those layers rely on the communications path for control signals, diagnostics and transactions.

The paper ends with a checklist that charge point operators, fleet and depot managers, engineers and procurement teams can use when specifying new sites or reviewing existing estates. It asks for site demand, downtime exposure, offline payment and authorisation policies, the resilience tier for each service, private encrypted routing and interoperability test evidence.