Growing electricity demand from electric vehicles poses risks to the bulk power system, NERC says
Energize Weekly, February 21, 2024
The growing demand for electricity to charge electric vehicles (EVs) – depending upon the timing of the charging – could threaten the bulk power system, according to a study by the North American Electric Reliability Corporation (NERC).
“NERC has determined that there are significant gaps in both the electric utility and EV charging community’s technical understanding, planning, and modeling of EV charging characteristics,” the study said.
The ability of EV owners to use home-based charging systems as well as public charging networks is adding an element of uncertainty in load forecasting for parts of the electric grid, potentially complicating bulk power systems operations.
The study called for better modeling of load demand and coordination between utilities and EV and charging-station manufacturers to fill “significant gaps” and “deficiencies” in the planning and managing of electric vehicle load.
The study focused on the use of home-based charging equipment: Level 1 and Level 2 chargers. A Level 1 unit requires standard 120-volt service, and a Level 2 charger needs a special line and equipment to accommodate 240 volts.
“Currently, EVs and their charging systems do not follow consistent control philosophies or performance,” the study said. “Simply put, two different EVs that use Level 2 chargers do not necessarily interact with the grid in the same way. This lack of standardization makes grid planning difficult. Efforts are underway within the electric industry to address this issue.”
NERC said that future studies will also have to consider Level 3 chargers, so-called rapid and ultra-rapid chargers, and Level 4 mega-chargers, which require even more electricity, as well as new types of loads, such as truck fleet charging.
The EV share of the global vehicle market is projected to grow to 50 percent of all new purchases by 2035, according to Recurrent an online EV trading platform, with a concentration of sales in the U.S. and European Union.
“The automotive industry is rapidly electrifying, and the generation, transmission, and distribution capacity and energy requirements for these new loads are trending upward,” the study said. “This added load and strain on the electrical grid has been projected to have vastly different outcomes depending on the scale of technology development, customer adoption, and the connection to the BPS [bulk power system].”
To offer an example of the variation in loads, NERC cited a California Energy Commission analysis looking at load duration profiles to identify which level of EV charger the end-use consumer is using at a given time.
The analysis saw one large peak of about 1,000 megawatts (MW) in the evening and a smaller peak of about 300 MW from the early morning to midday. About 800 MW of the evening peak came from Level 1 and Level 2 charges, with Level 1 chargers accounting for most of the demand.
The midday peak was composed mainly of workplace Level 2 chargers, followed by public Level 2 chargers and Level 3 fast-chargers.
Comparing the two peaks in magnitude shows that the evening peak is roughly three times greater than the midday peak, but NERC cautioned that this could change depending on how additional infrastructure buildouts for public charging stations, industrial charging capabilities and workplaces adopt faster chargers.
“As the rapid electrification of the fleet continues, increased cross-sector awareness, collaboration, innovation and information sharing will be essential to closing these knowledge gaps, meeting future demand and ensuring grid reliability, resilience and security,” Soo Jin Kim, NERC’s vice president of engineering standards, said in a statement.
