Duke Energy’s (NYSE: DUK) 402-kilowatt battery project at the Rankin Substation has been chosen by PowerGrid International magazine as its Project of the Year, reports the Charlotte Business Journal.
The project aims to integrate the local power grid with renewable energy, and the battery itself allows Duke Energy to smooth over minute-by-minute variations in power flow from the nearby National Gypsum 1.2 MW rooftop solar plant.
From the Charlotte Business Journal:
“As clouds roll by, solar output can go from 100 percent to practically zero,” says Dan Sowder, Duke Energy’s senior project manager. “With enough solar, that could disrupt the electrical grid. The Rankin Substation project is testing whether our battery setup can smooth out the fluctuations caused by solar’s intermittent output.”
Duke Energy has 12 nickel-chloride batteries in place at Rankin, set up as one large battery. The individual units were made by Italy's FIAMM Energy Solutions, while the control system’s electrical design comes from Chicago's S&C Electric Co.
Duke has been monitoring the system since late 2011, making adjustments to achieve the most efficient integration of the intermittent power supplied by solar projects to the main grid. That main grid, of course, needs to run at constant power levels.
The Rankin project is part of Duke’s series of test projects in such renewables/grid integration. Other projects are located in Texas, North Carolina, and Indiana.