More EV charging plugs can beat bigger power, Kempower finds

At a public charging site, the more useful number may be the plugs drivers can reach, not the largest power figure on the sign. Kempower’s analysis of North American sites connected to its ChargEye software found that sites with eight plugs delivered 128,342 kWh, more than twice the 61,453 kWh recorded at four-plug sites.

The relationship was sizeable but not proof of cause. Plug count had a 0.63 correlation with site utilization, compared with 0.228 for total installed charging power. Kempower’s white paper does not say how many sites it studied, how long it observed them, how utilization was calculated, or whether it controlled for location, traffic, pricing, site age and reliability.

The mechanism is power sharing. Kempower’s distributed setup connects multiple plugs to a centralized power unit, while software shifts electricity between vehicles in 25 kW increments according to what each car can accept. If one vehicle’s charging curve falls from 250 kW to 100 kW, unused capacity can move to another; when enough is available, a vehicle can receive up to 320 kW.

Kempower says sites using distributed charging averaged 83% higher utilization than sites with fixed-power dispensers. Its analysis suggests around 100 kW of available power per plug when all connectors are occupied, rather than a grid connection sized for every charger’s maximum output at once.

So what changes in practice? Operators could add access for more drivers and let software distribute a shared power budget as charging demand changes, potentially avoiding an oversized grid connection. The result is a design lead, not a guarantee: the figures show correlation, and no independent study of the analysis has been published.