community Microgrids

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Community microgrids are similar to Resilient Community Grids in that both are designed to serve a community, both serve multiple customers over the electric grid, and both are good platforms for DERs. Both are generally implemented by utilities or by utilities working with community organizations. 

Community microgrids, however, differ from Resilient Community Grids in several important ways. Unlike Resilient Community Grids, community microgrids do not usually emphasize protection of multiple critical infrastructure and their interdependence.  Community microgrids are typically implemented over the distribution network and usually cover the area served by a single substation.  By contrast, Resilient Community Grids are implemented over the transmission network and cover the areas served by multiple substations, some of which can host community (or other) microgrids. 

Community microgrids are a relatively new concept and have no single common objective or application.  Their objectives and applications tend to be very community specific.  Many are intended to use only distributed energy resources, especially renewables, and do not use  existing utility-scale resources. Although they are implemented over the electric grid , they are not intended to be a significant resource for the regional electric grid.  Often, they have been implemented as one-of-a-kind demonstration projects with no clear pathway to replication. 

Embedding one or more community microgrids within a Resilient Community Grid enables those community microgrids to improve electric grid resilience and creates an incentive for replication.  While Resilient Community Grids and community microgrids differ, embedding community microgrids within a Resilient Community Grid has several advantages for both which increase the benefits of both. In specific, embedding:

•    Broadens locations and increases scale for community microgrid resources,

•    Provides higher value for DER used to secure critical infrastructure,

•    Creates a natural and expandable platform for managing distributed assets,

•    Provides a more flexible way of integrating internal and external markets,

•    Is a low-cost way to provide resilience to a broader community,

•    Provides the ability to prioritize and phase-in distributed assets, and

•    Is a natural link to the wider regional grid and markets.

The feasibility and benefits of embedding community microgrids within Resilient  Community Grids are very area-specific.  Embedding other types of microgrids serving single facilities  or campuses within a Resilient Community Grid also adds a layer of defense to those facilities or campuses and enables coordination between the Resilient Community Grid and the microgrids.