The 24 MWh battery storage park developed by Duke Energy Renewables to store power generated by the nearby Notrees 153 MW wind farm in west Texas became operational in December 2012. The project was announced in 2009 and is supported by a matching a $22 million grant from the US Department of Energy (DOE) which is part of the DOE Office of Electricity Distribution and Energy Reliability (OE) effort to modernize the electricity grid while enhancing security and reliability of the infrastructure. The battery park is comprised of 24 one MWh modules. All the electricity generated from the facility will be sold by Xtreme Power to Wal-Mart Stores Inc. (WMT).
Duke Energy is currently working with the Energy Reliability Council of Texas (ERCOT) to determine how best to use the faciity in stabilizing the grid, either to dispatch stored energy to increase frequency or absorb energy to decrease it.
Performance data will be collected from the battery storage system by the Electric Power Research Institute (EPRI) to help assess the broader potential for deployment of storage solutions. Sandia National Laboratory will analyze technical and economic data. The results will shared publically through the DOE Smart Grid Information Clearinghouse.
China announced a 36 MWh battery park in May 2012.