Driving down the winding road at high speed is not the time to think about your destination or plan your journey. But that’s just what utilities might be guilty of when it comes to the inevitable surge of electric vehicles. By the time they’re actually rolling in the large numbers predicted just down the road, it might be too late for utilities to benefit fully from the increase in demand while at the same time preventing the disasters that not being fully prepared could entail.
Adoption of electric vehicles – EVs – is accelerating. Sales were up 36 percent year over year from 2015 to 2016, and as new models are introduced at prices below $30,000 after rebates, sales will no doubt continue to accelerate. Several of the 15 models now available have a range of 200 miles on a single charge, making them practical for most day-to-day driving. Bloomberg New Energy Finance expects EV sales to surge to as many as 640,000 annually by 2021. Major manufacturers expect to expand their offerings in the next five or six years: Ford by 13 new models, GM by 20 and Volkswagen hopes to replace each of its existing models by EVs by 2030. Volvo announced that starting in 2019, all of the cars it introduces will be either hybrids or solely battery powered.
That’s not to say we’re anywhere near replacing the existing fleet of cars, but there’s no doubt the rate of EV growth will continue to accelerate. The Rocky Mountain Institute estimates there could be as many as 2.9 million EVs on the road within five years. That theoretically translates into an increase in electricity demand of 11 terawatt hours, which, the Institute points out, is equivalent to the entire demand of the state of New Hampshire. At a time of slowing demand that could mean a significant boost to electricity sales. And if a recent report from the Smart Electric Power Alliance is correct, demand could soar to 551 TWh by 2040.
Utilities stand to benefit from the growing number of EVs in ways that go beyond the increase in demand. If EV charging is managed intelligently, it could become a boon to the distribution system, but that means getting the hardware and software support in place before demand increases significantly. Managed charging, as it’s called, combines infrastructure and communication signals sent to a vehicle or via a charger to influence a driver’s decision on when to charge the car. Through managed charging, load can be managed and the battery potential of EVs can be harnessed by allowing them to act in discharge mode, in which EVs would essentially inject power back into the grid during power spikes, such as heat waves.
Using EVs as a source of back-up power to stabilize the grid in this way, however, relies on the next step in vehicle-grid integration, known as V2G; at present this is in a preliminary stage of development, dependent on regulatory changes that are just being considered. All of this assumes a broad and rapid upgrade of the system, from grid-level to end-use. That will take very large investments over a short period as well as public acceptance of a close utility-customer partnership that much of the public views as an invasion of privacy.
For all that utilities stand to benefit from the wider adoption of electric vehicles they are also at very real risk if they are not prepared to meet the increased demand for power. Accommodating that demand presents a steep financial challenge; failure to meet it risks dangerous system failure.
A moderate commute of 25 miles requires between 6- and 8kWh for today’s EV models. That’s almost equivalent to the power needs of a small household. In other words, each new EV in a neighborhood is the equivalent of an extra small house. That can quickly add up on the local level to the point where the “last mile” in the system is seriously overloaded. Relying on time-of-use rates, which shift peak demand, won’t work by itself, since drivers are likely to simply shift charging to start at the moment rates drop, in essence creating a new peak-demand period. And while these new hours might coincide with peak generation for a renewable source such as wind, the new demand will still impose significant stresses at the last mile and shorten the life of the local transformer. If multiple EV owners use the same distribution transformer they can quickly overload it, causing damage and outages. The Sacramento Utility District, for instance, has estimated that approximately 17 percent of its transformers may need to be replaced as a result of the new demand and elimination of cool-down periods that would result from EV charging. The estimated average cost to replace each transformer is $7,400. That’s a lot of cash.
Modernizing the distribution system, from the grid down to the local level, is essential, regardless of the market penetration of electric vehicles. EVs add to the demands for modernization already posed by renewables, distributed generation and cyber security. It’s not a question of if, but of when. Modernization, including advanced demand response, data management and telemetry, becomes even more urgent if the projections of EV growth are anywhere near accurate.