Handbook of Energy Storage for Transmission or ... - W2agz.com

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3
T&D SYSTEM ENERGY STORAGE SYSTEM
APPLICATIONS
This section addresses the following T&D applications for which NAS batteries are particularly
well suited:
• Load leveling, typically 3 to 8 hours
• Power quality protection, 30 seconds and up to hours for power disturbance mitigation
• Automatic generation control (AGC), control power interchange and frequency management
for events up to one hour
• Wind generation stabilization for hours of firm power delivery
Representative applications are described in more detail in Section 3.1, top-level energy storage
system requirements for these applications are provided Section 3.2, and NAS battery
performance with respect to requirements is characterized in Section 3.3. It should be noted that
the functional attributes of the PCS, including the grid interface, are important elements of both
cost and performance. It should also be noted that combining functional requirements where
appropriate leads to improved economics. Examples of the economics of combined function
applications are addressed in Section 4, and include load leveling combined with AGC and
power quality mitigation combined with peak shaving.
3.1 Energy Storage System Descriptions
The following T&D system energy storage applications are representative of the primary
functions listed above. Specific sizes have been selected for the convenience of NAS battery
system arrangements and to facilitate comparisons.
1. 10MW distribution substation installation for ~8 hr load leveling (utilizing 200 NAS
PS Modules): Strategically located energy storage systems for load leveling are
deployed to avoid or defer T&D system upgrades in locations constrained by access or by
the admissibility of generation options. In most instances, this application does not
require rapid response. That is, scheduled startup over a few minute interval is adequate,
and such configurations avoid the expense of grid-interactive 2 power electronics and the
2
For the purposes of this document, the term “grid interactive” describes a continuously connected, inverter-based
power conversion system capable of providing immediate voltage and frequency support to the grid, as well as
power disturbance mitigation, to the extent of stored energy.
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