Sometimes the old ideas become new again … such is the case with chill storage or ice storage. Say you have a big high-rise building with air conditioning installed. In peak hours on hot days, your air conditioning use puts a lot of strain on the network, threatening a blackout. So if you are fortunate enough to be in a state that allows dynamic pricing and/or has an interruption/curtailment program at its ISO (I have the New York ISO in mind here), the high costs of producing peak power may lead to high prices and calls for interruption in those hours.
But what if you make ice overnight and let it melt during the day?
Because electricity is needed to make the ice, water is frozen in large silver tanks at night when power demands [and therefore prices — ed.] are low. The cool air emanating from the ice blocks is then piped throughout the building more or less like traditional air conditioning. At night the water is frozen again and the cycle repeats.
The quote is from this Yahoo article, which discusses the ice storage system that Credit Suisse has installed in the almost century-old MetLife Tower in New York City.
Ice storage at Credit Suisse lowers the facility’s peak energy use by 900 kilowatts, and reduces overall electric usage by 2.15 million kilowatt-hours annually — enough to power about 200 homes.
The article does a good job of pointing out that ice storage reduces peak use, overall use, and thus saves the customer money, making it a worthwhile investment. But notice also that this reduction means that it’s good for the environment.
Dynamic pricing is the driver here. Dynamic pricing aligns economic interests and environmental interests. Without the price signal and the price incentive, the impetus to make the investment to install such a system is nonexistent.
Note also that this technology begins to chip away at the tired old canard that “electricity can’t be stored”. Here’s a fairly cost-effective way to do it, if you’ve got a big enough building.