Smart Capabilities Will Help EV Chargers Manage Load
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- Mar 13, 2020 11:59 am GMT
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When electric distribution companies began adapting their grids to accommodate two-way power flow from residential solar power generation systems and other distributed energy resources, I often compared their efforts to the efforts by cable companies to allow two-way data flow over their networks so they could deploy broadband and on-demand services.
I stopped doing that after talking to a power industry veteran who pointed out that if a cable company did its work incorrectly, the result might be a customer not getting HBO, while if an electric utility made a mistake, the result might be a customer’s house burning down.
I remembered that discussion when I came across an article on the Australian website CarAdvice about an issues paper on electric vehicles that the Australian Energy Market Commission put out last month. In the article, Harry Hamann, the CEO of GET Electric, said he regularly encounters developers who don’t know how much power is used by the electric vehicle chargers his company installs.
"One of the issues in this building we’re working on at the moment is the amount of power they have available — it sounds like a lot, but it's running lifts, lighting, air con, etc.,” he said. “So the building doesn’t have capacity to provide any more energy and we could burn the substation down.”
To make sure that doesn’t happen, Hamann said, the chargers his company installs have automatic load management so they throttle down if there’s too much demand, as there might be if everyone in the building has their air conditioning on.
Peter Colacino, the chief of policy and research at Infrastructure Australia, the island continent’s independent infrastructure advisor, told CarAdvice that widespread EV charger deployment could lead to a power-grid version of the complications internet customers can encounter when everyone in a neighborhood is trying to stream Netflix at the same time.
"It’s the distribution part of the network — the substations that will come under pressure because there will be this extra demand on top of the established grid," Colacino said.
"If there’s a substation with a certain capacity, not everyone will be able to access that demand, so it would also create instability issues in the network and could ultimately degrade the equipment — I don’t know it would catch on fire but it would certainly break."
Making sure things don’t escalate to that level will require an awareness of how much power EV chargers, especially ones that provide quick charges, use. The Australian Energy Market Commission’s issues paper says that connecting a public charging station with eight chargers built in Adelaide in 2017 to the grid was the equivalent of connecting 100 new homes to it.
Chargers with smart capabilities also will help, and Blink rolled one out earlier this month. The charging station owner/operator has developed a charging station system with a local load management capability that will allow up to 20 charging stations to be deployed on a single 100 amp circuit by intelligently allocating power among them.
When one EV is charging, Blink said, it will get the system’s maximum output of nearly 20 kilowatt hours. When other EVs begin charging, the system recognizes that and reallocates power equally among all the EVs drawing from it. And when an EV finishes charging, the system recognizes that and reallocates the power that was going to it.
“The advanced charger intelligence supports multiple charging ports while delivering the fastest level 2 charge possible,” Blink CEO Michael Farkas said. “When installed on a single electric circuit, it can help minimize installation costs.”