Albany Times Union

Prepare grid now to power EVS

- By Eilyan Bitar Eilyan Bitar is an associate professor in the School of Electrical and Computer Engineerin­g at Cornell University, specializi­ng in power systems and electricit­y markets.

Less than 2 percent of all cars sold in America today are electric, but that will soon change. The internal combustion engine’s firm grip on American transporta­tion is loosening and for the first time a vision of an all-electric vehicle future is coming into clear focus. It’s a vision that may become reality in a matter of decades, and one driven by declining battery costs, progressiv­e policy, consumer demand and the world’s largest automakers.

Volvo says it will make only electric vehicles by 2030 and General Motors has announced plans to go all electric, completely phasing out gasolinepo­wered vehicles by 2035. Officials in California intend to ban the sale of new vehicles powered by internal combustion engines by the same year. Sensing a looming shift in the market, many other automakers like Ford and Volkswagen are investing heavily to expand their electric car offerings.

But even with this great momentum, the transition to an all-electric car future won't be possible without careful planning and coordinati­on with the power grid and the companies that manage its operation — a reality made all the more pressing in light of deadly power outages in Texas following a winter freeze.

Today, most people charge their electric cars when they come home in the evening — when electricit­y demand is typically at its peak. If left unmanaged, the power demanded from many electric vehicles charging simultaneo­usly in the evening will amplify existing peak loads, potentiall­y outstrippi­ng the grid’s current capacity to meet demand.

To accommodat­e the increase in that demand, utilities and grid operators—operating as they do now—would need to build new power plants to produce enough power, and expand transmissi­on and distributi­on infrastruc­ture to carry that power from the generators to the electric vehicle chargers. In states like Texas and California, where the transition to electric vehicles is accelerati­ng rapidly, these enhancemen­ts to the grid infrastruc­ture would cost tens of billions of dollars. And they would take decades to complete. To minimize these costly upgrades, utilities must rethink how they manage demand.

Timing is everything. Very often, EV owners don’t need their cars charged immediatel­y after they park at home or at the office—just within a reasonable window of time before they expect to leave. In an effort to tap this flexibilit­y, many utilities have begun to offer electric car owners time-of-use rates, where the price of electricit­y varies over the course of a day, being cheapest during off-peak hours.

While this might seem like a sensible approach, it won’t solve the peak load problem posed by EVS, and may make matters worse. At best, time-of-use rates will encourage some electric car owners to charge during offpeak hours. At worst, such incentives will synchroniz­e electric car charging patterns, as many EV owners will program their vehicles to begin charging simultaneo­usly at the start of the off-peak pricing period—a phenomenon that has been observed in a number of utilityrun trials. At moderate to high levels of electric car adoption, time-of-use rates may ultimately backfire — creating new demand spikes in the middle of the night, because of their synchroniz­ing effect on EV power demand. A greater degree of coordinati­on is needed.

To more effectivel­y manage the charging times of electric cars on their power distributi­on networks, some utilities are exploring the possibilit­y of directly controllin­g the electric car chargers. This may seem invasive, but could be one essential tool to minimizing strain on the grid — and saving electricit­y customers billions of dollars.

As part of this effort, utility company New York State Electric and Gas, in collaborat­ion with researcher­s at Cornell University, is piloting a new approach to controlled charging, where electric car owners can use their smartphone­s to specify how long they intend to leave their vehicles plugged in by selecting from a menu of “deadlines” that offers lower electricit­y prices the longer they’re willing to delay the time required to charge their cars. After customers select their preferred deadlines, a smart charging algorithm actively controls the power being drawn by their electric cars every minute to minimize overall strain on the grid, while ensuring that every customer’s car is fully charged by its deadline. Customers get their energy when they need it and the utility can optimally coordinate the delivery of that energy to avoid spikes in demand. Everyone benefits.

The ability to actively control the charging of electric cars at scale also has long-term implicatio­ns for the decarboniz­ation of the transporta­tion sector and the capacity to fuel this transforma­tion by clean renewable electricit­y. One challenge limiting the large-scale grid integratio­n of renewable energy resources, like wind and solar, is the intermitte­ncy in their supply of power. Through optimized charging, electric cars can be used to balance that intermitte­ncy by acting like a giant battery—absorbing renewable power when there’s a surplus, and injecting some of that power back into the grid if it’s needed at a later time, a concept known as “vehicle-to-grid.” Such coordinati­on would give rise to a symbiotic relationsh­ip between electric cars and renewables, where electric cars are used to buffer the intermitte­ncy of renewables, and renewables supply clean power to electric cars.

EVS are coming. Market forces and government policies will ensure they become part and parcel of Americans’ lives. The question now is whether the grid will be ready.

If left unmanaged, the power demanded from many electric vehicles charging simultaneo­usly in the evening will amplify existing peak loads, potentiall­y outstrippi­ng the grid’s current capacity to meet demand.

 ?? Photo illustrati­on by Jeff Boyer / Times Union ??
Photo illustrati­on by Jeff Boyer / Times Union

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