Advancing Energy Storage
The ability to store electricity and dispatch it on demand could be a true game-changer for the energy industry. Potential benefits of energy storage include improved grid reliability, greater ability to depend on renewable power, and reduced emissions as a result of more efficient use of conventional generation. Duke Energy is testing multiple energy storage technologies at distributed generation sites (close to where electricity is used) and at power plants.
By mid-2011, two small-scale energy storage systems will be in place in a south Charlotte, N.C., neighborhood that Duke Energy uses as a “living laboratory” for next-generation residential energy technologies. We will evaluate how the systems’ batteries can provide electricity during periods of peak demand.
In addition, we plan to place a large-scale battery at a substation that serves a National Gypsum facility in Mt. Holly, N.C. We installed more than 5,200 rooftop solar panels at the National Gypsum site in 2010 as part of our $50 million N.C. distributed generation program. The substation battery will be capable of delivering significant amounts of power when cloud cover reduces solar energy production.
Beginning in the fall of 2011, a battery will also back up a solar array at our Marshall Steam Station in North Carolina.
Duke Energy intends to match an approximately $22 million grant from the U.S. Department of Energy to install a 24- to 36-MW battery system at the 153-MW Notrees Windpower Project in West Texas. The Notrees energy storage system will be capable of storing 24 to 54 megawatt-hours of electricity, subject to final design. The system could mitigate some of the inherent variability in wind-powered generation and allow greater integration of renewable energy onto the grid. Another goal of this project is to demonstrate how storage technologies can enable renewable power facilities to supply electricity to customers when they need it most — not just when the wind is blowing or the sun is shining.