IEEE Electrification Magazine - March 2015 - 51

microgrid ownership, third-party generation participation,
investment recovery, and inclusion in the utility rate case. As
these challenges are being addressed, a more widespread
deployment of community microgrids will be witnessed in
power systems to the point that these smart communities
may act as a core component of future power systems.

weeks. The impact of these events on consumers could be
minimized by the deployment of community microgrids,
which allow the local supply of loads even when the supply
of power from the utility grid is not available.

Reliability

Perhaps the most prominent benefit of community microgrids
is the improved security as they could potentially mitigate the
impacts of physical and cyberthreats. The community
microgrids increase security of power delivery to critical facilities, such as hospitals, emergency response centers, water stations, transportation systems, food banks, and shelters within
the electrical boundaries. These facilities can provide secure
oases in the event of catastrophic disturbances to the utility
grid. The secured electric supply is enabled by operation in the
islanded mode in case of physical damage to the utility grid.
The islanded operation, enabled by on-site generation, allows
for the microgrid to maintain continuous supply to missioncritical loads during major grid disturbances (Figure 3). In addition to physical security, microgrids enhance the cybersecurity
aspects of the distribution system. By sectionalizing power
delivery into smaller segments and localized distributed control, microgrids can limit the impacts of cyberattacks. The
impacts could be experienced in specific areas instead of causing a widespread circulation to all grid operations. Community
microgrids also provide protection in numbers. As the
microgrids are distributed throughout the power grid, they are
not likely to be targeted at once, hence improving cybersecurity.

One of the most important benefits of community
microgrids is to improve consumers' supply reliability. Electric utilities constantly monitor consumers' reliability levels
and perform required system upgrades to improve supply
availability and to reach or maintain desired performance.
Consumer reliability is typically evaluated in terms of
system/customer average interruption frequency/duration
indices (e.g., SAIFI, SAIDI, CAIDI, CAIFI, etc.-see IEEE 1366-
2012, IEEE Guide for Electric Power Distribution Reliability
Indices). Outage causes, such as storms and equipment failure, impact reliability levels by increasing the average frequency and duration of interruptions; however, when a
community microgrid is deployed, these metrics can be significantly improved. This is due to the intrinsic intelligence
(control and automation systems) of community
microgrids and the utilization of DERs that allow islanded
operation from the grid. Since generation in community
microgrids is located in close proximity to consumer loads,
it is less prone to being affected by T&D grid disturbances
and infrastructure issues. Additional flexibility to provide
service under these conditions is provided by the ability to
adjust loads (e.g., demand response) via building and/or
microgrid master controllers. Improved reliability can be
translated into economic benefits for consumers and utility
due to a reduction in interruptions, costs, and energy not
supplied. The magnitude of these benefits is dependent
upon load criticality and the value of lost load as well as the
availability of other alternatives such as backup generation
or automatic load transfer trips.

Resiliency

Emission Reduction

Resiliency improvement is observed as a complementary
value proposition of microgrids. Resiliency refers to the
capability of power systems to withstand low-probability,
high-impact events by minimizing possible power outages
and quickly returning to normal operating state. These
events typically include extreme weather events and natural disasters such as hurricanes, tornados, earthquakes,
snowstorms, floods, and cyber- and physical security
attacks, and terrorism. Recurring and seemingly increasing
intense seasonal storms, which many utilities are facing
every year, could also be included among these events. The
recent hurricanes in the United States as well as a documented attack on a California substation and the potentially significant social disruptions have spawned a great deal
of discussion in the power and energy industry about the
value and application of microgrids. If the power system is
impacted by these events and critical components are
severely damaged, e.g., generating facilities and/or T&D
infrastructures, service may be disrupted for days or even

Community microgrids could be accredited as rapid
enablers of renewable energy integration to distribution networks. Renewable energy resources may cause significant

Benefits of community Microgrids
Community microgrids introduce unique opportunities
for consumers and for the operation and planning of the
power system, as outlined in the following sections.

Security

Figure 3. Community microgrids improve security by mitigating the
impacts of physical and cyberthreats.

IEEE Electrific ation Magazine / March 2 0 1 5

Table of Contents for the Digital Edition of IEEE Electrification Magazine - March 2015