A clustering effect of plug-in electric vehicle (PEV) charging among homeowners, known as uncoordinated charging, could require future upgrades to electricity distribution infrastructure, according to research from the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL).
Matteo Muratori, a transportation and energy systems engineer at NREL and author of the new Nature Energy paper, “Impact of Uncoordinated Plug-in Electric Vehicle Charging on Residential Power Demand,” looked at the impact PEV charging might have on a residential distribution transformer.
NREL said that Muratori’s research found that a problem arises when people in a certain geographic area began buying PEVs and plugging them in to recharge upon returning home, creating the uncoordinated charging phenomenon.
Muratori’s research also looked at whether households used less-powerful Level 1 charging or more-powerful—and therefore faster—Level 2 charging. NREL said that Muratori found that as more PEVs are added to a neighborhood, and a higher charging power is adopted, “the distribution infrastructure might no longer reliably support the local electricity demand.” He also noted that higher demand could shorten the expected life of a transformer.
According to NREL, earlier studies on how PEVs might affect the grid assumed utilities would have some control over when charging occurs, (a.k.a., coordinated charging), which will greatly facilitate PEV integration. Muratori said that might be true in the future, but not necessarily. Future research, Muratori added, should focus on understanding consumer behavior to determine charging requirements.
“Realizing the full benefits of vehicle electrification will necessitate a systems-level approach that treats vehicles, buildings, and the grid as an integrated network,” Johney Green Jr., NREL’s associate lab director for Mechanical and Thermal Engineering Sciences, said.