Energy storage plays a key role in DoD mission assurance as it is the backbone of microgrid systems. Some of its benefits include
- Minimal to zero wasted energy generated from the renewable sources as the energy is either stored for future use for events such as grid outage or is fed back to the utility grid.
- Seamless transition between alternative generation sources (e.g., solar to wind on a cloudy day) to provide a continuous source of energy.
- Savings obtained through reduction in demand charges by peak load shaving.
- Revenue generated through participation in utility ancillary service programs by selling excess energy to the grid.
Out of the different categories of ESSs (e.g., mechanical, electrical, thermal, and electrochemical [battery]), Battery Energy Storage Systems (BESS) have made significant advancements in technology, cost, and market penetration for use with renewable energy applications. According to recent studies,  the market penetration of BESS in smart grid applications is expected to more than double by the year 2024.
In recognizing the need and potential savings opportunity, ESTCP has demonstrated several of the latest energy storage technologies, such as the following:
1) Integration of a 1MVA, 576kWhr BESS that will work in concert with microgrid controls to alleviate renewable energy intermittency, improve island-mode operations, and reduce demand charges and peak load stress on the main transformers and other grid equipment ( Sodium-Metal-Halide Battery Energy Storage for DoD Installations [EW-201246]).
2) Integration of the advanced Zn/Br battery and Intelligent Power and Energy Management microgrid control technologies with the installation site’s infrastructure to peak shave and island the building circuit for 72 hours under controlled loads ( Zinc Bromide Flow Battery Installation for Islanding and Backup Power [EW-201242]).
3) Advanced thermal ESS that uses a phase change material (PCM) to store thermal energy at pre-determined temperatures, providing a minimum of 15% chiller plant energy reduction, 30% chiller plant energy cost savings, 40% peak demand reduction, and, when replacement is due, a 40% reduction in chiller sizing ( Latent Energy Storage Systems [EW-201514]).