Community energy storage: What is it? where is it? how does it work?

IREC attorneys Joseph Petta and Erica McConnell explore the challenges and opportunities of this latest community energy model.

The sharing economy is growing feverishly worldwide. Whether ride-sharing, tool-sharing or home-sharing, there are new value streams and new benefits to participants never before envisioned. Energy markets are no exception and are experiencing similar community-oriented revolutions.

Over a decade ago, the first community renewable energy (aka shared renewable energy) programs emerged, enabling multiple energy customers to participate in and share the economic benefits of a wind or solar energy system. Today, more than 14 states have enabled shared renewable energy programs, and hundreds of utilities offer some form of community or shared renewable energy program to their customers. More recently, “community choice aggregation” has sprung to life as a compelling alternative for communities looking to drive more renewable and clean energy development.

The latest community energy model to make waves: community storage. What is it? Where is it? To what extent is it, or could it be, “shared?” And, what can we expect from this new brand of community energy in the future? In this article, we explore the concept of community storage, provide an overview of projects and programs across the country, and offer some important insights on the challenges and opportunities for this novel concept. 

What does community storage mean?

Community energy storage is currently a concept without a precise definition. It could be said that an energy storage system is community storage if it is (1) located within a community with defined boundaries, (2) serves such a community or (3) both of these things. This definition will tend to exclude bulk or utility-scale energy storage serving the utility and/or ratepayers as a whole, and singular, behind-the-meter (BTM) storage systems that primarily serve the building or home to which they are connected. In theory, anything between these two use cases could be community storage.

The California Public Utilities Commission (CPUC) has broadly defined community storage as storage connected at the distribution feeder level, associated with a cluster of customer load. The services these types of systems could provide include (1) capacity for excess generation from distributed energy resources (DERs), (2) integration of higher penetrations of intermittent renewable resources (through, e.g., power quality regulation and “smoothing”) or (3) backup power during outages.

Not to be confused as simply a microgrid (although storage on a microgrid would meet the broad definition above), community storage has at least four use cases recognized by the CPUC so far:

  1. Connected directly to the utility distribution grid at the distribution feeder, and operated by the utility for the purpose of distribution reliability;
  2. Individual BTM batteries in a geographic community, operated by the utility as a single unit during some hours of the day to provide bill management or local distribution grid services;
  3. In front of the meter (IFOM) within a community, operated to provide services to local customers;
  4. Behind a single meter serving a large campus or military base.

As several of the following examples demonstrate, any of the use cases described above could involve storage as a component of a community or shared solar project.

Community storage can theoretically encompass a wide range of storage technologies, including batteries and electric vehicles (EVs), as well as thermal storage such as ice storage, electric space heaters and water heaters. The examples discussed here mainly involve advanced battery technologies — lithium ion and other battery chemistries other than lead acid.


Source :

Smart Grid Bulletin February 2019

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