Dive Brief:

DC Fast Charging stations operated by Hawaiian Electric next week will begin charging customers based on the company's time-of-use rates rather than a flat rate currently in effect.

The new rates are designed to alter customer use of the stations, encouraging shorter use times and greater access while offering the cheapest rates while there is excess solar on the system.

The change will go into effect Dec. 12, at company-operated fast chargers on the islands of Oahu, Maui and Hawaii.

Dive Insight:

New time-of-use rates are expected to alter use patterns at HECO charging stations, but utility officials say they will closely monitor changes to ensure the result is benefiting the public.

“Technology now allows us to set rates in a way that gives customers more control and are fairer to other drivers and all our customers,” Brennon Morioka, Hawaiian Electric general manager for electrification of transportation, said in a statement. “We expect many drivers to charge for shorter times and save money, which we hope will improve access and reduce waiting times at our most popular charging stations.”

HECO said that with the flat rate currently in use, drivers are in effect paying more per mile for short sessions than for long sessions. Based on use patterns, the utility expects drivers charging electric vehicles with small or average-sized batteries will pay less than they do now. Owners of electric vehicles with larger batteries will likely need to spend more to fully recharge near-empty batteries.

Generally, HECO estimated that a typical electric vehicle gets about 3.5 miles/kWh. The HECO utilities operate a dozen EV fast chargers across their service territories and have approval to install a total of 25.