Electric vehicles have zero tailpipe emissions, are more energy efficient, and deliver a better driving experience than gasoline-fueled vehicles. But the value of an electric vehicle goes well beyond the parking lot or freeway: the battery packs that enable an electric vehicle’s range can also be a huge resource for our electricity grid.
One of the fundamental challenges of managing the grid is ensuring a constant balance of supply and demand. Without this balance, we would rapidly see damage to our electrical equipment and degradation in our energy supply. Since the grid for the most part lacks substantial storage to smooth out fluctuations in supply and demand, grid operators have a delicate and high stakes dance to perform to keep generation and consumption closely matched.
As electric vehicle ownership rises, their job will get a whole lot easier. While individual vehicles are tiny resources and invisible to the wider grid, millions of such vehicles plugged in and smartly aggregated make for gigawatts of storage. We call this “vehicle-grid integration” (VGI), and it has huge promise.
Click here to download the high-res PDF of this infographic.
In future, energy will be drawn down into vehicle batteries or pushed back onto the grid to deliver important grid services like frequency regulation (keeping the grid’s electrical frequency at consistent levels), spinning reserve (quickly meeting sudden spikes in demand or drops in supply), renewables following (enabling maximum usage of variable generation), and even emergency power for the home and local distribution grid.
The value of this storage will not only accrue to utilities and grid operators. In modern electricity grids, services like frequency regulation are marketable products with real value. In fact, pilot projects are already deploying electric vehicles to provide grid services and generating revenue for vehicle owners. The EV can provide value in other ways as well: homeowners can save on their energy bill by using vehicle battery storage to buffer their energy demand; when coupled with rooftop solar, the EV could even help homes go off the grid entirely.
Despite this potential, and the growing number of real world projects connecting electric vehicles to the grid, a number of negative myths and perceptions endure.
“Electric vehicles break the grid”– a common misconception now thoroughly debunked not only by academic study but by utilities themselves. A recent Southern California Edison study found that less than 1% of recent distribution upgrades were related to electric vehicles. In fact, since EVs can be a significant resource for a stable and efficient grid, there is more reason to worry if they are not allowed to integrate.
“Grid services break vehicle batteries”– all batteries degrade with use, and the misplaced fear was that using electric vehicle batteries to pump energy in and out of the grid would dramatically reduce their capacity. Not so. In fact, recent studies show that the greatest risk to battery capacity is driving, degrading capacity by 2-3% a year. The impact of using a vehicle for grid services and home power needs will have costs orders of magnitude less, while generating - by some estimates - $300 per year for the vehicle owner.
“The technology isn’t ready”– tell that to the Department of Defense, which announced last year it was investing $20 million in purchasing electric vehicles (including plug-in hybrid electric tanks; image courtesy of InsideEVs.com) capable of storing and returning energy to the grid; or to the University of Maryland, which has been using electric vehicles to sell energy back to the PJM market since early 2013. Indeed, “V1G”(whereby the vehicle charges or doesn’t charge, depending on grid needs) is possible now and already being actively pursued by utilities; “V2G”(whereby energy can flow both ways) capability is less widely available but spreading fast.
“People will never let their vehicles be a part of vehicle-grid integration”– EV drivers care deeply about their choice of car and want to help where they can. Consequently, demand for participation in VGI programs outstrips supply. In addition, as EV ownership continues to rise, we are likely to see drivers recognizing and responding to what they can save by using their vehicle at home to reduce energy costs, and what they can earn from offering grid services.
So if the technology is capable, the benefits clear and the costs minimal, why aren’t we already seeing widespread use of this powerful resource?
In short, the politics and institutions governing the US grid were never designed for electric vehicle services. Operators are accustomed to managing big power plants, not small and dynamic mobile storage. This means that while in principle the EV can offer great value to electricity markets over other forms of storage or supply, few markets explicitly recognize this value. Similarly, the routes to market are limited and the barriers to entry are high. Few markets are currently ready for electric vehicles, and there remain expensive metering and registration costs. Political and institutional barriers preclude all but the most committed electric vehicle storage companies.
Fortunately, this is all changing – and fast. State agencies in California, the state leading the nation in EV ownership, are pushing hard to get EVs integrated into grid operations. Other states and markets are even further along in making their markets more amenable to electric vehicles. Broader trends towards more rational, open and market-oriented regulation of electricity bode well for the future, as does the growing trend towards distributed generation and increasing power in the hands of small producers. Electric vehicle storage on the grid and in the home is here to stay.
Photo courtesy of United States Air Force, ID 041027-F-2034C-010.