As electric vehicles become commonplace, will the grid be able to handle the extra load? Too many cars plugging in at once might cause disruptions and necessitate costly infrastructure upgrades....
Industry giants start the EV revolution.
us,” says Michael Rowand, director of technology strategy at Duke Energy. “Our rate structures, our planning issues, our regulatory environment is completely foreign to them.”
Misconceptions and gross simplifications actually ran both ways, initially. Car companies thought of electricity simply as fuel, with little understanding of how utilities make money, the vagaries of rate commissions and state regulators or the nuances of investor, public and cooperative ownership. By the same token, utilities often compared EVs to appliances, not fully considering that these machines draw power at varying voltage and intermittent times, then drive across town and plug in somewhere else—completely unlike a clothes dryer or air conditioner.
But while the two industries have important differences, they share one critical commonality:
“They’re both giant, capital-intensive industries that take a long time to fundamentally change,” says Mark Duvall, director of electric transportation at the Electric Power Research Institute.
But the seeming inevitability of EVs taking “a long time” was a luxury neither side could afford. By the middle of the last decade, decision makers in both industries acknowledged that collaberation was needed to craft technical standards and devlop a common vocabulary. In 2007, the Infrastructure Working Council (IWC) was convened to bridge the gap.
Managed by EPRI on behalf of the industry stakeholders who fund it, the IWC set about collating the various efforts of industries and regulators to develop EV standards. The first challenge: a universal charger.
Starting With the Plug
“The automotive companies and the utility companies made it very clear that there needed to be one single connector standard throughout North America, whether you plug your car into 120 volts or 240 volts,” says Duvall. “It had to be simple and cheap and safe and every vehicle had to be able to plug into every charge station.”
The IWC went to work, along with the Society of Automotive Engineers, to design a universal charging system. The result, after a two-year effort, was a standard device for connecting the car to the grid, known as the Electric Vehicle Supply Equipment (EVSE), able to accommodate different types of EVs with varied requirements for battery charging.
For the Chevy Volt, for example, a plug-in hybrid set to go on sale in December, and which will travel only a short distance on battery power, drivers can make do with a so called “Level 1” charge—basically a standard wall socket using existing wiring—but only so long as they aren’t in a hurry. That’s because the full charge at 120 volts will take about eight hours.
A faster charge—whether for a fully elecric vehicle or a plug-in hybrid with an auxillary internal combustion engine—would require a 240-volt “Level 2” charge. The EVSE connector will work for both.
“It’s a very good standard, it takes into account a lot of vehicles,” Duvall says. “People call them chargers, even companies that make them call them chargers, but they’re not technically chargers in my mind because they don’t convert power. EVSE provides AC electricity to the vehicle and the vehicle has an AC to DC converter on board that charges