Among the many provisions of Massachusetts 2021 comprehensive transportation bill (H.5248), the state required utilities to study and present alternatives to traditional EV charging rate design. Traditional rate designs can penalize EV charging stations with high “demand charges”, a charge linked to the maximum total amount of energy consumed at once, which tends to be high in short bursts when EVs are charging.
This issue is especially pronounced with direct current (DC) fast chargers, which can power up an electric vehicle to 80% full in 20 minutes. At the time of passage, there were just 90 publicly available fast-charging stations in the state, offering a total of 345 outlets. The economics of demand charges, which can exceed 80% of the costs to charging stations, partially explain the lag.
Utilities have 180 days from the signing of the bill to file their rate proposals, which will then be open to public comment before the Department of Public Utilities decides whether to approve the plans.