A microgrid provides energy surety independent of the grid, which allows installations to be energy independent and resilient. The controls, which form the backbone of a microgrid system, manage loads and distributed generation to meet economic, performance, security, and other objectives while ensuring safe, reliable operation.
Microgrids offer numerous advantages that outweigh their initial cost:
- Flexibility – Through optimized control of interconnected loads and generation resources, microgrids can reduce energy consumption while maintaining the reliability of the islanded microgrid. Microgrids can switch priorities among loads, as mission requirements change.
- Reliability – As microgrids are interconnected, if one generation asset fails, it is instantly backed up by another connected asset.
- Energy Security – In the event of grid outage, microgrids transition to islanded mode with minimal disruption providing seamless continuity of power to critical loads.
- Energy Savings – Savings achieved through peak demand and load management by participating in demand response, ancillary service markets, and real-time pricing programs.
Though microgrids offer improved mission assurance, DoD has been slow to adopt the technology. Some of the barriers for implementation  include high upfront costs; lack of knowledge and expertise required to manage the microgrid procurement; concerns about cybersecurity; and lack of guidance on how to define energy security requirements.
There have been numerous advancements in the microgrid and control technologies. ESTCP has funded many of the latest advancements in microgrids addressing specific technical challenges and other barriers to microgrid adoption.
Some of the microgrid systems demonstrated or being demonstrated by ESTCP to enhance the security, flexibility, and reliability of electric service to the base, and to generate cost savings include the following:
1) Creating a centralized microgrid cluster for monitoring and control of power generation and consumption for three interconnected bases and providing comprehensive, real-time situational awareness so that base command and operations can manage power as they manage other critical aspects of their missions ( Secure Automated Microgrid Energy System [EW-201340]);
2) Building a microgrid system that integrates distributed diesel generation, solar photovoltaic (PV) array, and grid-scale energy storage with the medium voltage utility grid and facility loads ( Microgrid Enabled Distributed Energy Solutions for DoD Installations [EW-201140]);
3) Integration of microgrid control systems with fast load shedding and battery ESS with onsite generation at military bases ( Portsmouth Naval Shipyard Microgrid and Ancillary Services [EW-201350]);
4) A cyber-secure microgrid that incorporates and fully utilizes high-penetration wind generation and energy storage to minimize the reliance on fossil fuel generators ( Hybrid Microgrid with High Penetration Wind for Islanding and High Value [EW-201606]);
5) Transportable microgrid with energy storage, which among other benefits offer smoothing out the power fluctuations for solar PV units, providing seamless power output during microgrid islanding and grid resynchronizing events, improved microgrid output power factor, and the capability to provide a minimum of four hours of 500 kilowatt (kW) power when operated in an islanding mode ( Transportable Microgrid with Energy Storage [EW-201605]);
6) A microgrid control framework that creates a dispatchable generation hub as the power base of a robust network of utility feeder interconnected facilities ( Strategic Microgrid Controls for Closely Sited Military Facilities [EW-201603]); and
7) A micro-auctioning control system, where each energy asset is treated as a participant in an energy micro-economy at a DoD facility and allows all connected energy assets to bid with each other, with relevant information such as time-of-day pricing, energy disruptions, and changing energy needs ( Micro-auctioning Control for Energy Generation and Consumption [EW-201601]).
 “Power Begins at Home: Assured Energy for U.S. Military Bases,” Commissioned by The Pew Charitable Trusts, January 12, 2017, http://bit.ly/PEWreport.