24VDC Li Expander Pak 1300 Operator Manual
June 2020
|
Solar Stik® Inc.
4
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GENERAL INFORMATION, PRINCIPLES OF OPERATION,
AND EQUIPMENT DESCRIPTION
Energy Storage Modules - An Introduction
Energy Storage Modules (ESMs or “batteries”) serve as the foundation for every Hybrid Power
System (HPS). When ESMs are employed in a power system, they can serve many different
functions:
• Backup power for critical loads when the primary power source fails
• Power when periods of “silent” operation are critical
• Use of renewable power generation is desirable
• Less reliance on grid-utility power is desirable (peak shaving)
ESMs are also critical to the operation of the Inter-Connect network. They open the system
architecture to allow multiple technologies to operate in concert. When functioning ESMs are
congregated within the Inter-Connect Circuit, their collective voltage is what allows the other
components within the network to perform their functions.
There is a wide range of energy storage technologies, including small- and large-format lithium iron
phosphate (LiFePO
4
) and lead-acid (Pb) batteries. ALL batteries are “consumable” parts of the HPS.
While the role ESMs serve can be widely varied, their function is quite simple: ESMs discharge
and recharge over time; this is known as“cycling”. Batteries are designed with a finite cycle-life
expectancy, and several factors will determine how many cycles a battery can endure before it is
depleted:
1. Cell chemistry
2. Operational environments and conditions
3. Charging and discharging rates
4. Storage conditions (even though it may not be actively cycling, the chemical reaction in a battery
never stops.)
All of these play roles in cycle-life expectancy, so selecting the best battery chemistry for a particular
application is critical.
Formats and chemistries are selected based on the requirements of a particular application, but
regardless of the battery type used in an HPS, there are two common attributes of all ESMs:
• Scalable—ESMs are scalable to meet System performance requirements.
• Modular—ESMs can be rotated, serviced, and/or swapped within the Inter-Connect network.
When assembling ESMs into an HPS for a particular application, the following need to be
considered:
• Consistency of chemistry
• Consistency of operating voltage
• Proper cycling
• Proper capacity for the intended load / application
• “One” battery bank (connected together, not disparately)