While much has been written about the intelligent grid of late, little attention has been focused on the role of energy storage in achieving its expected benefits. Energy storage is an essential...
Energy Storage: It's Not Just Load Leveling Anymore
of electrical equipment, enabling the increased penetration of renewable generation, and improving the reliability of U.S. electricity delivery. DOE goals include energy security and enhanced productivity of American business.
n STORAGE COMPONENTS. An assessment of storage technologies, focusing research efforts on storage components. Projects planned for the next few years cover (1) prototype advanced storage (e.g., flywheels or SMES) for power quality and reliability and, (2) advanced batteries for transportable energy storage systems.
n INTEGRATED SYSTEMS. Research that could increase the efficiency of electricity use and support development of renewable generation-storage systems and improve T&D reliability.
The DOE plans to publish a Handbook on Energy Storage for Renewable Systems, offering unbiased technical guidelines for the PV and energy storage communities. %n7%n
Applications Currently Available
Recent advances have greatly expanded the range of available technologies and applications, leading to many promising new opportunities for energy storage. Table 1 provides an overview of the present state of energy storage technologies. Following is a brief review of some of the exciting energy storage projects being developed in the United States.
INDUSTRIAL MANUFACTURING (RELIABILITY). High-power energy storage systems, which address the $26 billion annual national power quality and reliability problem, provide a few minutes of protection for commercial/industrial customers. %n8%n
A project co-sponsored by DOE is based on the PQ2000 power quality system, developed by AC Battery/Omnion. In a 50-50 cost-shared, $2-million project, the PQ2000 system has been used as the basis for the design and construction of the Transportable Battery Energy Storage System, the nation's first trailer-mounted, integrated power quality system. TBESS is a 2-MW/15-second system that can be easily located to solve highly critical problems. The system is being tested by Virginia Electric Power Co. and will enable the utility to provide premium power services to select commercial/industrial customers. The PQ2000 also is being used by Oglethorpe Power Corp. for a lithography plant in Homerville, Ga. During the first six months of operation, the system corrected more than 90 percent of the plant's power quality events.
ENVIRONMENTAL CONTROLS (POWER QUALITY). A 3.5-MW VRLA battery energy storage system installed at a lead-acid battery recycling plant in Vernon, Ca. is designed to improve productivity by providing multiple customer benefits such as peak demand reduction and uninterruptible power. The system's primary benefit is its ability to carry critical loads during power outages, ensuring that pollution control equipment remains operational. Since its installation in 1996, the system has greatly reduced the power quality events that had previously resulted in increased lead emissions and costly non-compliance fines.
ISLAND POWER SYSTEMS (ANCILIARY SERVICES). Large energy storage systems enable utilities to have a source of electricity in reserve to prevent service interruptions in the event of a failure of a power generator. Puerto Rico Electric Power Authority installed a $21 million battery energy storage plant at its Sabana Llana substation in 1994. This, the first of several storage units to be installed, guarantees instantaneous power when one of the island's thermal power plants suffers a shutdown. The quick-response battery system can simultaneously provide 20 MW of spinning reserve during outages, frequency