Above: Beta Engineering's Executive Vice President, George Brashear (far left), participated in a recent groundbreaking ceremony for a battery energy storage system in Glendale, Calif.

Hailed as a “holy grail” for maximizing the integration of renewable energy sources into the power grid, advances in battery energy storage systems promise utility-scale solutions for storing and releasing energy as it is produced and needed.

These systems help utilities respond to increasing demand, and provide better power quality and grid stability. Battery storage systems can provide backup power to start power plant generators in the case of a system-wide outage.

While little storage exists in today’s power grid, the concept of energy storage is nothing new. One hydropower storage solution involves pumping water uphill to a reservoir during periods of excess electricity. When demand increases, the water is released to fall downhill and generate additional electricity. However, this solution is only available in limited areas of the country that have access to hydropower.

Pumped storage offers discharge times in the tens of hours. In contrast, electrochemical batteries provide shorter periods of energy storage, with discharge times ranging from approximately one to six hours. Lithium ion batteries dominate the market for grid-scale battery storage in the United States—partly because of their ability to ramp up quickly in applications, such as frequency regulation, requiring less than four hours of storage. Other technologies, such as sodium-sulfur and certain types of flow batteries, have an advantage for grid services requiring longer discharge, according to the Electric Power Research Institute.

Regarded as a novelty only a few years ago, these systems are beginning to shift from concept to reality. In late 2016, California utilities quickly adopted plans to bring several new battery energy storage facilities online. The California Public Utilities Commission called on these utilities to develop additional storage solutions to help prevent the risk of power outages after leaks in a Los Angeles natural gas field essentially left it out of commission.

California is relying on energy storage to meet its longer-term clean energy goals as well. In 2013, the CPUC required that the state’s three investor-owned utilities procure 1,325 MW of energy storage by 2020.

Beta Engineering is constructing a 2 MW battery energy storage system in Glendale, Calif., next to the Grandview Substation. The utility will use this small-scale system to gain experience to develop and incorporate a larger scale battery component into its system. Construction is expected to be completed by April.

While battery energy storage systems offer great potential, existing barriers must be addressed before widespread market adoption can occur. Reducing cost, expanding manufacturing, increasing power density and improving product durability are a few of the hurdles that industry observers say must be overcome.