Microgrids

Definition

The U.S. Department of Energy (DOE) defines a microgrid as "a group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid[...]and can operate in either grid-connected or island-mode."

Microgrid Advantages

• Enables an installation (or portion of the load) to island from the public grid during a grid outage
• A microgrid can enable an installation to provide demand-response capabilities to a utility, and can reduce strain on the electric grid
• This can be a source of revenue to finance the microgrid

Microgrid Limitations

• Can increase operations and maintenance (O&M) for installations
• One alternative is to have a third-party own, operate, and maintain the microgrid. However, military personnel must be trained to operate the system during an emergency or have an agreement in place to provide access to the installation for the third-party
• Typically installed at the distribution-level so there is still potential for a fault on the distribution system
• Microgrids do not replace building-level generators, but instead add redundant sources of power
• Microgrids often require replacing several decades old switchgear

USAF Relevance

For the military, installing a microgrid enables the operation of an electric distribution system in the absence of power from the electric utility grid. A microgrid can provide an additional redundancy to a single building, campus or section of an installation, substation, or the full installation. A microgrid does not necessarily replace backup generators in the event of electrical outages within an installation distribution system (e.g. falling tree limbs, construction accidents).

For military installations, a control system can reduce the amount of manpower required to operate an installation distribution system, especially during a grid outage. This will require training and skilled personnel for operation.

Potential Sites

Multiple (Examples: FE Warren AFB, Joint Base Andrews, Joint Base McGuire-Dix-Lakehurst, Offutt AFB)