Plug Count, Not Peak Power, Drives EV Charging Site Utilization, Kempower Finds
Analysis of North American data suggests increasing available plugs is more effective at attracting drivers than increasing total installed power.
Electric vehicle infrastructure success depends more on the number of available plugs than raw power capacity, according to a new analysis by Finnish charger manufacturer Kempower. The findings suggest that accessibility is the primary driver of site utilization in the North American public charging market.
Using its ChargEye cloud software to analyze public charging data, Kempower found that the number of charging plugs has a significantly stronger correlation with site utilization than total installed charging power. Specifically, the correlation between plug count and utilization was 0.63, while the correlation for installed power was only 0.228. This indicates that plug count has roughly three times the relationship with site utilization as the total power available at a location.
The Shift Toward Accessibility
This data marks a shift in how operators view the deployment of fast-charging hardware. Historically, the industry focused on "peak power"—the maximum speed a single vehicle can achieve—as the primary metric for site quality. However, Kempower's data suggests that drivers prioritize the probability of finding an open plug over the theoretical maximum charging speed of the station.
Kempower utilizes a distributed charging architecture, where multiple plugs connect to a centralized power unit. This system allows power to be shifted dynamically between vehicles based on real-time demand, rather than allocating a fixed amount of power to each individual dispenser. This flexibility allows a site to support more vehicles simultaneously without requiring a linear increase in grid capacity.
Implications for Infrastructure
For charging network operators, these results suggest that infrastructure deployment should prioritize accessibility over raw peak power. By focusing on increasing the number of plugs, operators can serve a larger volume of drivers and potentially increase revenue without the prohibitive costs associated with upgrading grid capacity to support maximum advertised speeds for every plug at all times.
As Jed Routh, vice president of markets and products for Kempower North America, noted, public charging is increasingly becoming an infrastructure utilization challenge rather than simply a power deployment challenge. The ability to manage how power is distributed across a site is becoming as critical as the total amount of power delivered to the site.
Future Outlook
While the correlation is strong, the analysis highlights a broader trend toward optimizing the user experience through availability. The industry now faces the challenge of balancing the demand for ultra-fast charging with the practical necessity of reducing queue times through higher plug density.
What remains to be seen is how these findings will influence future zoning and grid planning for EV hubs. If the industry moves toward a "more plugs, smarter power" model, it could lower the barrier for entry for smaller site operators who cannot secure massive power drops from local utilities but can still provide high-utilization service to the public.