Public Fast Charging Rates: Cents/kWh v. Cents/minute
Fast charging of electric vehicles in BC is an important topic these days. (See our companion article Public Fast Charging Rates: BCUC Proceedings.) A frequently heard argument from EV advocates is that the price should be on an energy basis (cents per kWh) rather than on a time basis (cents per minute). Dozens and dozens of letters of comment made this point in the BCUC’s ongoing proceeding regarding BC Hydro’s public fast charging rates. However, there is a regulatory impediment to energy-based pricing for fast charging service that can only be resolved by the federal government.
The regulatory problem in a nutshell is that the federal Electricity and Gas Inspection Act prohibits selling electrical energy without using a federally certified ‘revenue grade’ meter (for consumer protection and fair trade), and there are no federally certified revenue grade meters for fast chargers (yet). There are numerous federally certified revenue grade meters for AC energy because AC has been used in electricity grids since the 1880s. However, fast chargers provide DC power, not AC power, to the EV. Measurement Canada has not yet approved any ‘revenue grade’ DC energy meters. Measurement Canada is only now beginning to develop the standards that it will use to determine if a specific type of DC energy meter will be certified.
To clarify, most if not all fast charging units do have an internal DC energy meter (often the charging session record shows the kWh delivered), but these have not been certified for billing purposes. It is uncertain whether the DC energy meters in existing fast charging units will be sufficiently accurate to meet the future standards.
Several potential work-arounds have been floated in the BCUC’s proceedings regarding BC Hydro’s and FBC’s fast charging rates. However, none of these appears to be viable. One suggestion is to use the existing revenue grade AC meter to measure the AC power coming into the fast charging site and then somehow allocate a portion of that AC power to each charging session. A fatal flaw with that idea is that it simply wouldn’t meet the legal requirement to use a certified meter to bill a charging customer on a cents/kWh basis. Another suggestion is to apply to Measurement Canada for an exemption from the requirement for a revenue-grade meter until standards have been developed and DC energy meters have been approved. The problem there is that that is not how the federal government has chosen to address the problem. Rather, the federal government has allocated funds to expedite the development of standards.
BCSEA has been concerned for some time about the absence of Measurement Canada technical standards for DC fast charging energy revenue meters in Canada. In March 2021, BCSEA commended Measurement Canada for beginning to develop such standards and said the sooner these standards can be implemented, the better. BCSEA’s key point was that while EV drivers want electric energy measurement (kWh) to not be systematically over-estimated, they do not need, and do not want, exquisite precision in the measurement of DC kWh for billing purposes. This is important, because extreme precision comes with extreme cost. The consumer protection and fair trade objectives have to be met without imposing unrealistic requirements on the fast charging providers and their equipment suppliers.
Measurement Canada has a website on its development of standards for DC fast charging energy revenue meters to enable cents/kWh billing: Measurement Canada, EV Charging Stations. It is currently inviting people to complete an online survey about EV charging billing approaches.