Storage Cooling Systems
Ft. Jackson, SC
2.25 million gallon chilled water storage system at Ft. Jackson, SC. Operational since 1996 with an annual electrical utility cost savings of $0.4M annually.
CERL,
Champaign, IL
A 30,000 gallon diurnal ice storage system cooling system containing 125,000 dimpled plastic water-filled balls that are frozen during off-peak hours. The thawing balls provide daytime cooling for CERL employees located in the 130,000 square foot main building. The shift of electrical demand from on-peak to off-peak is measured to be over 200 kW during the 1997 cooling season. The savings is estimated to be $15,000 annually.
Total construction cost was $162,500 for the tank, ice balls and control system. The total storage capacity of the system is 1700 ton-hours. As a part of cool storage demonstration program for the Illinois Power (IP) customers, IP contributed $50,000 for the preliminary study of the cooling system.
Army Problem and Solutions
- Problem Cooling demand charges cost up to 40% of electric bill or high kWh cost under Real Time Pricing (RTP)
- Solution Make ice or chilled water during off-peak period or when the kWH charge is low.
Systems in the Current Market
- Chilled Water Storage (CWS) for central cooling plants - dollar savings as well as energy conservation (Stratified chilled water storage)
- Diurnal Ice Storage (DIS) Cooling systems for individual buildings - dollar savings with off-the-shelf systems (Ice-on-coil, ice harvester or encapsulated ice systems)
Success Stories from Field
- CWS system at Ft. Jackson, SC -$0.4M/yr savings since 1996.
- Ice-on-Coil DIS system at Yuma Proving Ground, AZ - $22.5K/yr savings since 1988.
- Encapsulated Ice DIS system at CERL, Champaign, IL - $15K/yr savings since 1997.