Even if EVs were to constitute 20% of the US car market, less than a 0.01% chance would exist of overloading healthy transformers, according to a new report from the Electric Power Research Institute (EPRI) released this week.
Posted by Staff
The findings from the free, 120-page study could relieve some utilities’ fears that EVs will overheat transformers. However, it also said that aging or already stressed transformers could be problematic when more EVs come online.
A “medium” projection puts EVs at 4% of the US car market in 2015, the report said. A “high” projection puts that number at 8%.
“The rapidly approaching commercialization of plug-in hybrids and EVs has created an urgent need for utilities to support the adoption of EVs by their customers, to prepare for the installation of residential, commercial and private infrastructure in their service territories, and to manage the impact of these new loads on the electric distribution system,” the report said.
One of utilities’ main anxieties about EVs is that additional load will accelerate deterioration. Transformers, the equipment in closest proximity to EVs, will endure the most wear, the report said. But that effect will be minimal for most transformers, because most EVs charge at below 0.7 KW.
Other interesting highlights of the report focus on ‘Off-Peak creating peak.’
Charging EVs during off-peak hours — touted as the way to ease their strain on the grid — could in fact create additional peak hours, according to the report. Some cars, such as the Volt, can program when to begin and end charging based on TOU pricing. Programming large quantities of EVs to begin charging at 9 pm and end at 6 am — both off-peak hours when EPRI assumes TOU-based charging occurs — would generate load spikes, it said.
Using time-managed charging would boost load 20 GW in 2030 and “most likely create a new system peak and raise it significantly,” the report said. About 73% of EVs would be available for charging during those off-peak hours, the report estimated.
Read more fascinating conclusions, including why ‘utilities can wait,’ and the full report HERE.