How virtual storage systems turn buildings into batteries

Editor's note: This is the second of a three-part series focused on virtual energy storage. Part I delved into the way buildings can be used as batteries. To learn more about energy storage and buildings, be sure to check out VERGE@Greenbuild November 12-13.

Terry Boston, PJM President and CEO, once remarked, “Energy storage technology is the silver bullet that helps resolve the variability in power demand.” When most people conceive of energy storage, images of massive battery banks, reservoirs for hydrologic pump storage, or compressed-air systems come to mind. Yet these capital-intensive “hard storage” approaches are expensive and fall well short our energy storage needs. If energy storage represents the “silver bullet” to variability in power demand, as Boston contends, we must embrace more nimble, lower-cost solutions.

Fortunately, these solutions exist. As we have outlined previously, “virtual storage” systems have the capacity to transform buildings into batteries. Virtual storage systems include a new generation of building controls and technologies that more effectively meet energy storage needs – at a lower cost – than most of hard storage technologies now receiving investment from utilities and VC firms. As our power demand becomes more variable, virtual storage systems have the potential to revolutionize energy delivery. Instead of energy supply matching variability in demand, virtual storage will allow energy demand to match variability in supply.

Electric Vehicles and Renewable Power

Enormous uncertainty surrounds the future of U.S. electricity demand. The unclear growth trajectory of electric and plug-in hybrid vehicles is one reason why. The figure below summarizes of various credible projections about likely new EV penetration in the U.S. in 2020, ranging from a 1 percent projection by the Energy Information Agency, up to 11 percent in the U.S. (and even higher in Europe) by Deutsche Bank.[1]

Where these vehicles recharge (or potentially discharge) will have dramatic consequences for the shape of load demand. Cars charging at work could add to peak-load demand. Or, if charged at home during off-peak periods, these vehicles could provide load demand to efficiently use nighttime wind. Alternatively, these vehicles could potentially charge at home, and then discharge some of their power back to the grid through connections at work during peak hours. The potential for electric vehicles to ameliorate — or possibly, worsen — electricity demand and supply will emerge as a large policy issue in the coming decade.

Next page: Creating our virtual future