By Pat Carolan, P.E., M.SAME  

Microgrids and the greater integration of distributed energy resources continue to gain traction throughout the United States and globally. As the nation’s largest consumer of energy, the Department of Defense (DOD) is also becoming one of the most visible adapters of microgrid technology. A recent study by Navigant Research found that DOD’s microgrid investments are expected to reach $1.4 billion a year by 2026.

Microgrids carry a number of benefits. They enable greater deployment of distributed energy resources such as renewable energy, including solar photovoltaic, wind, and battery storage—all of which can provide sustainable power and can help reduce greenhouse gasses. Microgrids bolster energy security because they can produce and distribute electricity and operate independently from the larger power grid. Perhaps the most significant of all microgrid benefits is the impact to energy costs. According to a recent study by The Pew Charitable Trusts, implementing these energy solutions at DOD facilities could save up to $1 billion annually.

Successfully installing microgrids will require a comprehensive understanding of impacts to the local grid, energy controls and a combination of economic factors. Proper design and configuration, including integration of existing assets, will also be key to meeting project goals.


Microgrids are integrated systems of multiple power generation sources and electric loads and can include renewable energy, fossil power and energy storage. They are able to operate in parallel with, or islanded from, the local grid. Many operate under a consolidated “smart” control and energy management system, which is able to analyze resources and control load/generation, optimizing resources in real-time and providing predictive analytics for maximum efficiency. These smart controls are key to integrating renewables such as solar and wind, which are highly variable and slightly unpredictable due to their reliance on weather conditions.

For military facilities that must be “always on,” microgrids can provide physical security and protection against cybersecurity risks. By not having to rely solely on a larger regional grid that may be more averse to compromises, on-base missions can continue uninterrupted.

Energy controls act as the “brains” of a microgrid, allowing power from back-up diesel or natural gas generators to be dispatched intermittently when renewable power is unavailable. For military applications, the major components of a microgrid are already on site, but additions could include installation of controls, switchgear upgrades and interconnections.

Battery energy storage allows energy managers to store and use energy on-demand. Using storage as a microgrid resource supports sustainability initiatives, efficient use of fossil-fueled resources, enhanced power quality, and supplements both wind and photovoltaic assets. Additionally, the declining costs of battery storage will continue to support the expansion of this technology.

For military facilities that must be “always on,” microgrids can provide physical security and protection against cybersecurity risks. By not having to rely solely on a larger regional grid that may be more averse to compromises, on-base missions can continue uninterrupted.

Many electrical organizations are still evaluating the feasibility of implementing microgrids. Findings from a Black & Veatch study, “Strategic Directions: Electric Industry Report,” indicate that about one-third of survey respondents (31 percent) have already developed, owned and/or operate distributed energy resources, including microgrids, while 17 percent are planning to deploy these energy solutions within the next 10 years. While it is important to note how microgrids can save on energy costs, optimal project design can achieve multiple goals for installations in sustainability, reliability and resilience.

DOD’s goal to deploy 3-GW of renewable energy throughout military installations by 2025 can be made significantly easier with microgrid solutions. Additionally, reliability and resilience can be achieved through bringing together new and existing assets, utilizing renewables as a component of a resilient system, resolving power quality issues, and active management of generation and load.


In San Diego, one of the military’s largest energy projects is being developed through a microgrid at Marine Corps Air Station Miramar. The base is in the process of establishing its own energy network that gives it the assurance and reliability needed to keep its operations in motion when regional blackouts occur.

A 200-kW solar photovoltaic carport at Marine Corps Air Station Miramar provides renewable power to and reduce energy costs, while providing energy resiliency for the base when utilized along with energy storage in a microgrid.


Black & Veatch and Schneider Electric, in a joint venture, are providing design and construction of the project. Once fully operational in late 2018, the microgrid will provide resilience, incorporate renewable energy, and allow operations at mission-critical facilities, including the base’s flight line, to continue if the utility power grid becomes compromised or damaged.

Construction began in September 2017 and will include the buildout of a new diesel and natural gas power plant and refurbishment of an existing building into an advanced energy and water operations center. The operations center will provide microgrid and plant operators and base energy personnel with direct control of the integrated microgrid control system, utilizing Schneider Electric’s OASyS SCADA software. The microgrid will integrate existing power generated from renewable energy sources including 3.2-MW of biogas from a local landfill and 1.6-MW of solar photovoltaic generation, along with future energy storage.


Project planning and subsequent milestones for the Miramar microgrid rely heavily on collaboration between all stakeholders, including government agencies, private industry, vendors, and installation personnel. Fortunately, for the last 10 years, Marine Corps Air Station Miramar has served as a test bed for renewable energy projects—notably as the site of early demonstrations for energy storage technologies.

In San Diego, one of the military’s largest energy projects is being developed through a microgrid at Marine Corps Air Station Miramar.

Partnerships with the National Renewable Energy Laboratory and the local utility, San Diego Gas & Electric, have led to analyses and studies for how the base could more efficiently use energy.Coordinating with specialized organizations and with local utilities can help structure microgrid designs for optimal cost-savings and resource utilization, as well as seamlessly integrating local grid resources.


As preparations begin for a microgrid project, it is essential to design for desired levels of resilience. Some bases may only need backup power for a period of up to 24 hours, while depending on mission requirements, a microgrid may be needed to serve an entire installation for continuous operation for an extended period of time. Resilience tier and design criteria have the most impact on costs. However, the most ideal projects are scalable and capabilities can grow over time to meet evolving needs. Pilot projects can better define actual load versus critical load requirements for facilities and help understand islanding scenarios and timelines. The most effective microgrids will save money by producing power more cheaply than the grid and solve specific sustainability, resilience and security objectives.

If military facilities are to meet DOD’s stringent energy goals, they must plan now to implement solutions that will benefit missions long-term. Microgrids provide a holistic solution to fortifying energy resilience and independence. When integrated with existing resources and connected to the local power grid, they can provide significant cost savings from operational budgets. Innovative projects such as the Miramar microgrid will carry lessons learned that then can be applied to facilities all over the world.

Pat Carolan, P.E., M.SAME, is Regional Operations Director, Federal Business, Black & Veatch;

[Article first published in the March-April 2018 issue of The Military Engineer.]