Fort Hunter Liggett Leads the Charge: Pioneering the DoD’s Net Zero and Mission Resilience Goals

Over a decade ago, the Department of Defense (DoD) recognized its place as the nation’s largest energy user, as well as the need to improve energy efficiency, avoid overtaxing the grid, and shift to renewable energy as a means of offsetting negative environmental effects, while meeting operational and installation needs.  The military services began by finding ways to make buildings, infrastructure, and utilities more efficient. Around 2013-14, the DoD adopted the Net Zero concept to reduce consumption by installing renewable energy sources. In 2017, the Department of the Army expanded this goal to include Mission Resilience.

In 2010, Fort Hunter Liggett (FHL) near King City, California was chosen by the Assistant Secretary of the Army for Installations, Energy, and Environment as one of the nine pilot installations for the Net Zero Initiative.  In 2017, SEA was contracted by FHL to provide Resource Efficiency Management (REM) services. With the focus on resilience, SEA REMs helped FHL conduct a groundbreaking ceremony in 2021, initiating the build of a $21.6 million electrical microgrid. This project aims to make FHL the first Army installation capable of achieving Net Zero for mission-critical operations, ensuring 14 days of energy resilience. This is a crucial step towards energy self-sufficiency across the DoD.

A microgrid is a self-contained electrical distribution system that can operate independently from the utility grid.  FHL has been preparing for this resilience project for several years.  Initial steps included upgrading and burying the medium voltage distribution system in the cantonment area. This set the stage for expanding the solar array at the Equipment Concentration Site and adding photovoltaic generation at the O&M yard. The generated power would be stored in batteries, allowing daytime electricity to be used at night. The entire microgrid system would be managed by an automated Supervisor Control and Data Acquisition (SCADA) system, which can respond to grid changes in as little as 1/30th of a second.

The microgrid has successfully helped FHL achieve its Net Zero goals.  Despite being an Army Reserve installation, FHL supports significant activities from the Army, Navy, and Special Warfare Groups essential for training initiatives.  If successful, FHL would serve as a model for other installation resilience efforts within the Department of the Army.  This innovative, fully integrated microgrid system will ultimately provide contingency electric power during power outages and persistent grid instability.

Once operational, the system will generate more electricity than FHL can consume annually, achieving the Army and DoD’s electrical Net Zero goal.  Although FHL will not fully disconnect from the power grid, it will have the capacity to export excess electricity in summer and import it in winter, balancing out to Net Zero.

Despite including battery energy storage in the contract, FHL will generate more electricity during the day than it can use or store. The SCADA system will manage this by curtailing solar array output to avoid overloading the grid.

FHL is an ideal pilot site for the Net Zero microgrid project, due to its size and scalability. Over the course of the project, SEA’s REM has identified challenges and improvements to establish best practices for other installations. Larger military bases worldwide can model their resilience efforts on FHL’s pilot work, mitigating risks and accelerating implementation based on lessons learned.

The initiation of any microgrid project is the culmination of over a decade of projects, development, and planning. It requires forward-thinking to generate DoD-wide projects at the grassroots level, representing a significant achievement.

FHL has developed one of the most advanced energy programs, largely due to exceptional technical and budgetary support from the Army Reserve Installation Management Directorate, Sustainment and Resiliency Division. SEA is honored to participate in this energy program and landmark pilot project, setting the stage for future resilience efforts across the DoD.