Quick quiz: Where can somebody find a very common substance that has the potential to drastically reduce energy spending – especially at peak price points when electricity is most expensive?
Answer: Any freezer.
Granted, the scale in the use of ice to cool a building and to cool a glass of ice tea is significantly different. But the bedrock principle of energy transfer is the same. Thermal cooling leverages that concept by freezing water at night, when the energy required to do so is less expensive. The melt water is stored and circulated as it is needed during peak demand times the next day. Thus, the heavy lifting — the energy-intensive process of freezing the water — is done at a point at which costs are lower.
Interesting use case studies were posted during the past few weeks. The Herald Tribune last week reported that a thermal storage system featuring 36 ice tanks is being used by the Sarasota County School District in Florida. It seems to be working: The state says that the district is paying 96 cents per square foot for energy, which is 24 cents less than average and ninth best among districts in the state.