This month’s issue of T&D World focuses on distributed energy resources. Battery energy storage systems (BESS) play a big part in that conversation and are more relevant to today’s utilities than ever before. Supportive public policies coupled with technological advancements and declining costs are providing real opportunities for battery storage to revolutionize the power industry. Battery storage technologies are being used by both utilities and consumers alike, changing the traditional utility relationship with customers.
Market Outlook Navigant Research anticipates that there will be a cumulative 35.5 GW of new energy storage built for critical infrastructure through 2027. According to experts with the Newton-Evans Research Co., the U.S. energy storage market will grow to more than $5 billion by 2024, which is about an eight-fold increase from 2019 levels. Approximately 25% of this anticipated storage capacity will address T&D issues directly.
T&D Applications Battery energy storage systems have the potential to revolutionize the power industry because they essentially disconnect supply from demand. Besides the obvious use of providing electric power, BESS has multiple T&D use cases such as enhancing reliability, improving the utilization of grid assets, and deferring infrastructure investment. Improving reliability is a common concern for mission-critical installations and commercial and industrial customers such as hospitals, large data centers, financial institutions, and complex manufacturing operations. Battery storage enables enhanced reliability by either avoiding local outages that may originate on the feeder with a BESS or islanding the feeder and maintaining power supply for customers. Energy storage technologies also provide flexibility in operating the grid through peak shaving, load leveling, and congestion relief on the T&D systems. BESS technologies are particularly useful in providing relief from congestion or during times of peak demand that would otherwise require curtailments. These capabilities all allow for more efficient utilization of grid assets and delay costly T&D infrastructure investments.
Storage Technologies The utility industry has done quite a bit of R&D as well as pilot projects related to energy storage. Advances in these technologies mean that batteries can now store more energy and deliver more power. Their life cycle has also increased, and maintenance has decreased. Three key technologies have the optimal characteristics to have a substantial impact on serving the T&D system and mission-critical installations. Lithium-ion (Li-ion) batteries are the leading technology for both utility-scale and C&I energy storage applications. Li-ion batteries are used frequently in electric vehicles (EVs) and other consumer electronics, which has brought down costs, increased capacity, and improved reliability. These characteristics also make them well-suited for critical infrastructure applications. A flow battery is a cross between a conventional battery and a fuel cell. It uses liquid electrolytes of metallic salts pumped through a core with positive and negative electrodes, separated by a membrane. As the liquid flows through the membrane, the ion exchange allows for charge and discharge capability. Flow batteries are often favored due to their low cost, long-duration, safety, and longer life cycle relative to other battery types. Hybrid battery-fossil fuel technology can improve the efficiency, flexibility, and resiliency of existing fossil-fueled power systems. Utilities like Southern California Edison have used them to enable peaker plants to operate at their lowest emissions configurations. They are also a ramping resource that enables the generation plant operators to ensure the voltage, phase, and frequency from the batteries match the power on the grid when a plant restarts and goes back on the grid. Hybrid plants can also provide a utility with spinning reserves and significant fuel savings.
Project Risks We’ve all heard about batteries in cell phones and other consumer goods catching fire, and unfortunately, the utility sector is no exception. The focus in this respect tends to be in Li-ion batteries, as they often seem to be the battery of choice due to declining costs. The fire risk of batteries has the full attention of the National Fire Protection Association, which has been developing standards and conducting new research. South Korea reported 23 fires at utility BESS sites in 2018. The U.S. has fared better with at least three significant storage-related fires. In 2012, a fire destroyed a 15MW battery storage facility at the Kahuku wind farm in Hawaii. Arizona Public Service (APS) experienced a battery fire in a 1.5MW system in 2012, and a fire and explosion at a 2MW battery Li-ion storage system in April 2019, and
The Future Is Bright The list of new utility storage projects and customer installations gets longer every day, which indicates confidence from utilities, developers, investors, regulatory bodies, and customers. With all the research happening in this area, I remain confident that the utility industry will continue to benefit tremendously from future advances in BESS technologies. Cost-effective storage has the potential to revolutionize the power industry. I don’t think we are there yet, but I think we will get there. In the meantime, we must also remain vigilant as we gain experience with rapidly evolving BESS technologies Stay safe until next time!