POWER July 2021 - 37

ENERGY STORAGE
sidered " passive " solutions, meaning
they activate from the pressure itself
and require no electronic intervention.
Suppression Systems. Fire suppression
systems are often recommended
to quickly reduce the combustible atmosphere
created from thermal runaway.
When a malfunctioning battery is
detected, either through gas, smoke, or
heat detection, the connected fire panel
may release one of two recommended
fire suppression systems: water mist or
gaseous agents.
" Fike recommends water mist as the
foundational system to protect a BESS, "
Jones said. " Water mist is very effective
at absorbing heat, so it's going to flash to
steam and absorb the heat from any fire
or heat produced during the thermal runaway
process. If you're using a pumped
water mist system, such as Fike's DuraQuench
system, you'll have a continuous
water supply, which provides that
continued cooling and inerting effect. "
Finally, water mist provides " three-dimensional "
coverage, allowing it to permeate
the entire space and reach even obscured
fires-something a traditional sprinkler
system cannot provide.
When there is a need to protect against
an incipient Class C fire that may occur
even before any battery cells are involved,
Fike recommends 3M Novec 1230 or FM200.
These fires may occur within a transformer;
inverter; or heating, ventilation,
and air conditioning (HVAC) motor.
" Oftentimes, even before the water
mist system is activated, we will also use
a gaseous agent system to suppress Class
C fires that are igniting somewhere outside
of the actual battery cells, " Jones said.
" That way you get the fast-acting gaseous
agent system to potentially put that Class
C fire out before it can turn into a Class B
fire that involves the battery cells. "
Detection Systems. One of the most
impactful decisions for limiting fire damage
and preserving the BESS is the
chosen method of detection. Various detection
options are available to identify
the stages leading up to and including
thermal runaway: temperature increase,
off-gases, smoke, and flame.
The earlier a malfunctioning battery
is detected, the sooner fire suppression
systems may activate. However, if suppression
systems are not installed, detection
is still essential as it can activate
HVAC vents to flush out off-gases, shut
down power, sound alarms, and notify
emergency responders. Detection options,
from slowest to quickest to activate,
include the following:
July 2021 | POWER
ods of energy storage also require protection,
such as those found within buildings.
The aforementioned temperature increases
can be monitored and detected, even
before off-gassing or thermal runaway occur.
Because these battery installations
are often located within manufacturing
plants, commercial buildings, or residential
areas, early identification of potential
battery failure is essential.
For example, thermal monitoring dis2.
Explosion vent panels are installed on the
top of battery energy storage system shipping
containers to safely direct an explosion
upward, away from people and property.
Courtesy: Fike Corp.
■ Traditional spot smoke detectors and
heat detectors are placed inside the
BESS enclosure to detect the presence
of smoke or heat. However, by
the time traditional detection activates,
thermal runaway of a lithium-ion
battery is well underway. This method
is not recommended for those who
hope to suppress the fire and preserve
the BESS.
■ Thermal imaging or flame detectors
are commonly mounted outside to
monitor multiple BESS units for fire
or increased temperatures from the
HVAC exhaust vents. Thermal imaging
provides added early warning when
combined with other detection methods
within each BESS unit. Flame
detectors will respond to open flame
and are required per IFC (International
Fire Code) 2021 for rooftop or garage
installations.
■ Honeywell Analytics industrial gas detection
detects presence of off-gas
within a BESS unit once it reaches a
certain threshold.
■ VESDA with integrated gas and smoke
detection continuously samples the
air for presence of gas or smoke particles
within a BESS unit.
■ Li-ion Tamer is specifically engineered
and designed for BESS fire protection.
It provides localized gas detection and
reporting within individual lithium-ion
battery racks.
Each of these detection methods may
be ideal for certain scenarios. It's the responsibility
of the safety solutions provider
to communicate the pros and cons
of each for the unique application.
BESSs in Buildings
While much of the industry has been focused
on portable BESSs contained in
shipping containers, various other methwww.powermag.com
plays
real-time temperatures of each
battery rack. Battery rack ambient temperature
is normally about 130F. If it
reaches 140F, the battery rack can be removed,
cooled, and repaired before offgassing
occurs.
Two types of thermal monitoring systems
are available: thermal monitoring
cameras and distributed fiberoptic thermal
monitoring cables. Thermal imaging
cameras may be used to monitor multiple
racks of batteries, monitoring for
not only overheated batteries, but also
for hot spots on metal or exhaust, which
may indicate the presence of abnormal
temperature increase prior to off-gas or
thermal runaway. Fiberoptic distributed
temperature sensing cables may be
routed throughout battery energy storage
racks. They can provide real-time
temperature indication and alarm on a
battery or rack basis to pinpoint the exact
location of an overheated battery. Software
is available with a virtual display of
the racks including actual temperatures
and indicated alarm areas, plus dry contact
relay or modbus outputs can be utilized
for equipment control.
Valuable Equipment Deserves
First-Rate Protection
Reliably protecting a battery energy storage
system requires a partner whom you
can trust. Multiple variables should be considered,
such as whether the BESS is located
in a rural or urban area, whether it's
contained within a shipping container or
a building, and whether the stakeholders
want to protect the batteries themselves
or just protect against the worst-case scenario.
Because explosion protection, fire
detection, and fire suppression are all important
considerations for mitigating the
effects of thermal runaway within a BESS,
it's recommended to find a partner who
can provide reliable solutions to fulfill each
of these safety requirements. ■
-Jim Vingerhoets is global product manager
for Explosion Protection, and Kevin
Montgomery is global product manager
for Fire Detection and Control Products,
both with Fike Corp.
37
http://www.powermag.com
POWER July 2021

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