When planning the expansion or retrofit of an existing building,
engineers should consider the advantages that a CALMAC energy storage system can provide.
Underwriters Laboratories Building
What is energy storage and how does it work? Energy storage is a
proven technology that takes advantage of low-cost, off-peak
electric rates to produce cooling energy for use when electric
rates are higher. A building’s chiller is used to charge
CALMAC’s IceBank® thermal energy
storage tanks with ice during less expensive
off-peak hours at night. The ice is stored in the IceBank tanks
and then used the next day during the discharge cycle to cool the
building during on-peak hours. Click here (PDF, 371 Kb) for
system schematics and a technical review of the energy storage process.
Operating chillers during nighttime hours improves energy efficiency
by 2 to 8 percent over non-storage systems operating during the day.
Dry-bulb temperatures are about 20°F lower and wet-bulb temperatures
5°F lower at nighttime hours, compared to daytime hours. Nighttime
operation improves the efficiency of all chillers, but especially
air-cooled chillers because the condensing temperature is controlled
by ambient dry-bulb temperature.
There are at least three energy storage strategies to consider: full storage,
partial storage, or a combination. Full storage shifts a building’s
entire cooling load to off-peak hours. The building’s chiller only
runs at night in order to charge the IceBank tanks. During the
discharge cycle, the stored ice is used to cool 100 percent of the
building’s load the next day. energy storage
is an ideal strategy for meeting the cooling load of a new building
expansion without adding chiller capacity.
With partial energy storage, IceBank tanks work in tandem with the chiller.
The chiller charges the IceBank tanks at night and continues to run
the following day during the discharge cycle. During the discharge
cycle, the chiller cools up to 70 percent of the building’s load and
the stored ice cools the remaining load.
A partial energy storage system configuration enables chillers to operate
at or near full load continuously, thus eliminating the inefficient
cycling and capacity modulation that accompanies part-load operation
and normally causes a chiller to operate at peak efficiency only 25
percent of the time.
Click here (PDF, 371 Kb) for system schematics and a technical
review of energy storage.
Additional design engineer benefits
- Dnergy storage works in conjunction with a customer’s existing chiller to meet a building’s increased cooling load while reducing energy costs.
- Provides a design with a chiller that is 40 to 50 percent smaller to minimize inefficient operation of oversized equipment, with minimal risk.
- Thermal Energy Storage design is similar to a chilled-water system and is not complicated.
- Provides customers with a demand-responsive cooling system.
- Provides customers a cooling system with fuel-source flexibility, on-peak or off-peak energy.
- Offers architects a path to ASHRAE 90.1 compliance or improved LEED™ ratings.
- Added design costs, if any, can be easily paid for with life-cycle savings.
- The size of air handlers, motors, ducts, and pumps can be reduced by 20 to 40 percent, which saves design time.
- CALMAC can provide a wealth of information to help engineers efficiently design a energy storage system.
- Click here for a complete list of other benefits.
installed an ice storage system years ago and it never worked properly and
was nothing but headaches. The thermal storage market started 20 years
ago with over 30 manufacturers, all employing different technologies.
Since that time, the technology has evolved, changed, and matured, and
today, CALMAC is the recognized thermal energy storage leader. The products
that CALMAC designs and manufactures have a proven track record for
performance and they are easy to apply. Today’s systems use standard
commercial chillers and factory-assembled ice tanks. CALMAC also can
provide information to help the designer, contractor, and operator
install the energy storage tanks.
Click here for complete product and specification information.
Click here for a partial listing of energy storage projects.
Please click here to contact any of
CALMAC’s regional managers for additional information or questions.