This tech could keep EVs from stressing the grid — and save money
If you’re a typical American, you come home from work and start flipping switches and turning knobs – doing laundry, making dinner, watching TV. With so many others doing the same, the strain on the power grid in residential areas is currently greatest. This demand will only increase as the world moves away from fossil fuels, and more people buy induction cookers, heat pumps and electric vehicles.
It’s a challenge for utilities, which already manage creaky grids across the United States while trying to meet growing demand for electricity. So now they are trying to turn electric vehicles from a burden into a boon. More and more models, for example, feature “vehicle-to-grid” or V2G capabilities, meaning they can send power to the grid as needed. Others are experimenting with what’s called active managed charging, in which algorithms stagger when electric vehicles charge, instead of all consuming energy as soon as their owners plug them in. The idea is that some people charge later, but still have a full battery when they leave for work in the morning.
A new report from the Brattle Group, an economic and energy consultancy, conducted for EnergyHub, which is developing such technology, used real-world data from electric vehicle owners in Washington state to demonstrate the potential of this approach, both for utilities and drivers. They found that a managed, active charging program saved up to $400 per electric vehicle each year, and that vehicles were always fully charged in the morning. Utilities also appear to benefit, as redistributed demand results in fewer early evening peaks. That in turn would mean a utility could delay costly upgrades — which it needs to accommodate increased electrification — saving ratepayers money.
Active managed charging works in conjunction with what’s called “time of use,” in which a utility charges different rates depending on the time of day. Between 4 p.m. and 9 p.m., when demand is high, prices are also high. But after 9 p.m., they fall. Electric vehicle owners who wait until later in the evening to charge pay less for the same electricity.
Time-of-use pricing discourages energy use when demand is highest, thereby easing the load and reducing the amount of electricity utilities must produce. But there’s nothing stopping everyone from tuning in as soon as the lowest rates go into effect at 9 p.m. As adoption of electric vehicles grows, this coordination problem may create a further surge in demand. “An electric vehicle alone can account for twice the peak load of a typical home,” said Akhilesh Ramakrishnan, managing partner of energy at the Brattle Group. “You get to the point where they start to have to be managed differently. »
This is where active managed charging comes in. Using an app, an EV owner indicates when they need to charge their car and how much charge their battery needs for the day. (The app also learns over time to predict when a vehicle will unplug.) When returning home at 6 p.m., the owner can plug in, but the car won’t start charging. Instead, the system waits for a certain time in the night to turn on the juice, allowing enough time to fully charge the vehicle at the designated time. “If customers don’t believe we’re going to get them there, then they won’t allow us to effectively control their vehicle,” said Freddie Hall, data scientist at EnergyHub.
The typical driver only travels 30 miles a day, Hall added, requiring about two hours of charging each night. By actively managing many cars in neighborhoods, the system can spread demand more evenly throughout the night: people will leave for work earlier or later than their neighbors, vehicles with larger batteries will need more time to recharge, and some will be nearly empty while others may need to refuel.
How Electric Vehicles Can Fix the Grid and Lower Your Electric Bill
They still get the lowest prices with time-of-use pricing, but they don’t tax the network by charging everyone at 9 p.m. “The results are actually very, very promising in terms of reducing peak loads,” said Jan Kleissl, director of the Center for Energy Research at the University of California, San Diego, who was not involved in the report. “This shows great potential for reducing electric vehicle charging costs in general.”
Active managed charging would allow the grid to accommodate twice as many electric vehicles before a utility would have to begin upgrading the system to handle the additional load, according to the report. (And consider all the additional energy demand from things like data centers.) These costs are inevitably passed on to all taxpayers. But, the report notes, active managed charging could delay these upgrades by up to a decade. “As electric vehicles grow, if you don’t implement these solutions, there will be a lot more upgrades, which will impact rates for everyone,” Ramakrishnan said.
At the same time, electric vehicles could help reduce these rates in the long term, thanks to V2G, a distinct emerging technology. It allows a utility to use electric vehicles stored in garages as a large backup power network. So when demand increases, these vehicles can send electricity to the grid for others to use, or simply power the home they are in, removing grid structure and reducing demand. (And think of all the fleets of electric vehicles, like school buses, with huge batteries to use as supplemental power.) With all that backup power, utilities might not need to build as many expensive battery plants themselves, projects for which ratepayers wouldn’t need to foot the bill.
Active managed charging and V2G could work together, with some batteries discharging at 6 p.m. when providing power, then recharging later at night. But this ballet will require experiments on a larger scale. “How are we going to be able to discharge a battery and charge it overnight? » said Hall. “Because you want it to be available the next day.”
To reduce greenhouse gas emissions as quickly as possible, the world needs more electric vehicles. It is now just a matter of making them benefit from the network instead of taxing it.
