Virtual energy storage: Using buildings as batteries

Editor's Note: To learn more about new energy technologies be sure to check out VERGE@Greenbuild November 12-13.

Thomas Edison once remarked “When we learn how to store electricity, we will cease being apes ourselves; until then we are tailless orangutans.” True to Edison’s insights, recent investment in battery banks, compressed air systems and ultra-capacitors show interest in solutions that improve energy storage technologies.  Utilities and the venture capital (VC) community are spending vast sums in search of solutions to curb peak power loads and to address the intermittency of renewable power sources. Edison would likely view these expensive investments in hard storage technologies as noble but misguided efforts to transcend our collective simian roots.

Better solutions within our grasp

The rush to invest in new capital-intensive storage technologies overlooks a larger, lower cost and lower risk opportunity -- what we call virtual storage. Unlike hard storage technologies, virtual storage does not require large capital costs. Instead, virtual storage proposes creating intelligent distributed energy efficiency as well as harnessing the latent potential in building structures and systems to dynamically modify building energy usage. Virtual storage promises to reshape energy demand to match a variable energy supply.

Virtual storage offers a far more cost-effective and lower-risk solution than hard storage technologies to solve most power supply and demand mismatches. The rapid rise of virtual storage will more effectively meet energy storage needs at a lower cost than most hard-storage technologies now receiving investment from utilities and VC firms. Shifting to a virtual storage strategy can save tens of billions of dollars, serve as a catalyst for the renewable energy industry, improve utility profitability, strengthen security and slow global climate change.

Buildings as batteries

Buildings represent close to 75 percent of electricity consumption.  Building energy demand peaks during hot summer afternoons when the need for air conditioning is greatest. While buildings are the dominant source of unbalanced load demand, buildings -- through virtual storage -- also represent the largest opportunity to cost-effectively reshape load, thereby saving tens of billions of dollars by avoiding costs relating to both inefficient generation and costs of transmission and distribution (T&D) infrastructure.

Some new technologies are designed to reduce peak power consumption. These will be part of “building as battery” designs meantl to achieve zero net energy. The new technologies are varied, including hardware solutions, energy efficiency control devices and smart grid solutions.

At one end of the sophistication scale is the application of cool paints (typically white) which reflect 80 or 90 percent of the solar radiation falling on a roof. This simple change very cost-effectively cuts solar heat gain and peak air conditioning load while reducing ambient local temperature. For example, in Washington DC, making roofs on city owned buildings cool would reduce ambient city temperature by 0.3 to 0.4 degrees.

Next page: Dynamic electrochromic glass