Ice-based energy storage, according to Tom Raffy, is a no-brainer.
The idea is simple: Water is frozen in the middle of the night, when the energy used to do so is inexpensive. It then is thawed and used for cooling the next day.
Raffy, the CEO of a hair and skin care products company GAR Laboratories, has been using the Ice Bear platform from Ice Energy for about a year as part of a demonstration project with the city of Riverside, California.
GAR uses the technology in buildings of 40,000 square feet and 50,000 square feet. Raffy said that time shifting the energy used to cool the company’s two facilities from afternoon to the pre-dawn hours has cut his average monthly electric bill from $571 to $117. “It is simple and it works,” he told Energy Manager Today. “The difference between the cost of electricity at 2 am and 2 pm is 20 to 90 times, depending on surcharges. It is shockingly more expensive [at peak times].”
Raffy decided to use the ice storage approach – or at least give himself the option of doing so — before he settled on Ice Bear. “I read about it and I was intrigued,” he said. “I had 20 year-old AC units on building and replaced them with ones with two coolant intakes, compressed Freon or ice. So I bought those units and knew I had the option and contacted Ice Energy and had them install four [Ice Bears] on one building three on the other.” Raffy said that the Ice Bear units each are 500 gallons. They are sealed and repeatedly freeze and thaw the same water.
Ice Energy – which introduced a home version of the Ice Bear product, the Ice Cub – is far from the only company offering products based on the concept. Some recent news:
Last week, Axiom Exergy said that it was chosen by Walmart for what it terms a “field demonstration” of its Refrigeration Battery at the retailer’s San Diego store. In the trial, tanks of salt water are frozen during periods of low energy costs. The frozen liquid produces refrigeration for as long as seven hours and, according to Axiom Exergy, reduce on-peak energy demand for refrigeration by 40 percent. The trial is being utilities that belong to the state’s Emerging Technologies Coordinating Council, according to the press release.
Also last week, CALMAC said that its system is being used by the Naval Post Graduate School’s Integrated Multi-Physics Renewable Energy Laboratory (IMPREL), which is in Monterey, CA. The press release says that IMPREL is a microgrid project that employs a variety of storage technologies and “a unique multi-physics approach to optimize the use of onsite sources of renewable energy.” CALMAC’s technology, the release says, is paired with solar and wind renewable energy sources to store cooling capacity.
Energy efficiency is a broad area. On one end, there are expensive and sophisticated measures that offer significant payback, but over a long period of time. On the other hand, simple steps such as moving to LEDs and deploying solar power. These approaches are accessible and offer much quicker payback.
Finally, there are steps that are in the middle. Storing energy as ice involves more than incidental changes to how a facility operates. For instance, Raffy says that the tanks have a 10 foot by 15 footprint – and his two facilities use a total of nine. Ice energy also requires a HVAC equipment that have two inputs.
Those inconveniences are balanced off by the apparent great savings that are possible. That, at least to one user, is compelling. “Making ice at 2 AM and using it during the day saves huge amounts of money,” he said. “It’s that simple.”