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Energy Efficiency

Published on May 22nd, 2010 | by Susan Kraemer


53 Megawatt Ice Energy Storage Project Begins In Glendale, California

May 22nd, 2010 by  

About 24 municipal buildings in Southern California are about to help ease the strain on the grid created by the peak need for air conditioning on hot California afternoons. Over the next few weeks, a consortium of municipal utilities in California will begin retrofitting government offices and commercial properties with systems that use ice made at night using cheap surplus wind power to replace air-conditioning that they would have required during the afternoon.


The first cheap energy storage cooling units housed at distributed sites on the buildings will be networked, providing utilities with a resource that can be dispatched as needed to help manage demand on the grid.

The 53 MW distributed energy storage project will demonstrate savings, such that if put into general use, would reduce fuel consumption by the nation’s utilities by up to 30%, using efficiency “negawatts”, and by individual building owners by up to 90%.

The units are made by Colorado-based Ice Energy, a recipient of the DOE 30% tax credits for investments in new, expanded or re-equipped clean energy manufacturing projects, for bringing much-needed jobs to upstate New York where it will scale up its manufacturing operations.

Over the next two years, the 11 small participating utilities will install 6,000 of the devices at a total of 1,500 locations, providing 53 megawatts of energy storage to relieve strain on the grid, and coordinated by the Southern California Public Power Authority.

The units make cheap ice overnight, when demand for electricity is low, using a high-efficiency compressor to freeze 450 gallons of water. In the middle of the day, the device shuts off the regular air conditioner for the peak afternoon hours and instead pipes a stream of coolant from the slowly melting block of ice to an evaporator coil installed within the building’s heating, ventilation, and air-conditioning blower system until the entire ice block has melted – which should be sized to take about 6 hours – to cover for the peak afternoon load on the grid.

The utility also saves energy at other points in the grid–for example, cooler power lines at night transmit electricity more efficiently. Although ice storage systems have been used in large commercial buildings – the Bank of America Building in Manhattan is a LEED-Certified example – these tend to be expensive custom-built designs. This project uses mass-produced scalable modular units.

At $5,000 each, these will be within the means of commercial property-owners, and would bring up to 90% reduction in individual building’s fuel use. For California, the implications are huge. Large-scale implementation of Ice Energy’s (already tried and tested) small modular units as energy storage for the grid would put off the need to build new power plants. And not just in the SCCPA utility district.

Image: Flikr user MichaelMiettinen and Ice Energy

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About the Author

writes at CleanTechnica, CSP-Today and Renewable Energy World.  She has also been published at Wind Energy Update, Solar Plaza, Earthtechling PV-Insider , and GreenProphet, Ecoseed, NRDC OnEarth, MatterNetwork, Celsius, EnergyNow, and Scientific American. As a former serial entrepreneur in product design, Susan brings an innovator's perspective on inventing a carbon-constrained civilization: If necessity is the mother of invention, solving climate change is the mother of all necessities! As a lover of history and sci-fi, she enjoys chronicling the strange future we are creating in these interesting times.    Follow Susan on Twitter @dotcommodity.

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  • Jake

    Well, this idea is similar in effect to only pumping water up to water towers only at night, which has been done since the 1950’s.

    The utilities are probably the greatest winners economically, as this practice shaves peak hour demand. What are we waiting for ?

    • We are all the greatest winners – both economically and ecologically

  • Clint Hightower

    Does anyone know how the coolant is circulated through the ice and what designs have been made to make the heat exchange from the coolant to the ice as efficient as possible? Are the condensing coils stired in an ice slurry or do fans condense the coolant? What media actually makes contact with the coils, air, ice, water, slush?…thanks

  • Matt S

    Great to hear about this project and that lower cost, modular thermal storage products are hitting the main stream.

    One clarification on this line though:

    “At $5,000 each, these will be within the means of commercial property-owners, and would bring up to 90% reduction in individual building’s fuel use.”

    Thermal storage does not reduce energy use but actually slightly increases a buildings energy consumption due to heat loss from the ice storage system (a well designed and insulated system would be just a small increase).

    The intent of these systems is what was mentioned earlier in the article, to offset the peak demand by transferring that energy use to the off-peak hours. As Susan says this has significant benefits both in transferring more demand to cleaner power sources and financially to those that are on a time-of-use schedule.

  • P Valenta

    I have been in the energy storage industry for some time – longer than Ice-Energy has been in business. I welcome them into this business and wish them success because more good manufacturers helps the industry progress.

    I am frankly very tired of the common comment that someone feeds authors of these articles that large chilled water energy storage systems using ice like “the Bank of America Building in Manhattan is a LEED-Certified example – these tend to be expensive custom-built designs”.

    The designs are custom but they are not expensive. In most areas of the country new designs with ice storage based chilled water designs cost no more than conventional chilled water. Chilled water retrofit projects tend to have paybacks of four years or less.

    Modular ice storage for chilled water systems has been in use for over 25 years and these systems have a proven track record. Best practices and product improvements have made these systems the product of choice because of its reliable and efficient operation as well as its affordablility.

    The inherent synergies of a total system design can lower connected load and offer incredible efficienies. Most of the larger custom ice storage projects are installed without a utility subsidiy. That fact alone says ice storage systems for chilled water systems are affordable.

    [SK: That is great to know: It would be great if it was implemented more often. Somebody from that industry needs to publicize it more! When I referred to my other BofA wind storage story as expensive; and custom, I was thinking that many people just don’t consider doing serious energy retrofit or design to save energy. BofA was LEED so it had access to good advice of LEED AP professionals. That advice is more expensive than your average plumbing warehouse in Glendale say is going to seek, that if there’s something modular and ready to just pop in, like these units, that this would therefor be more likely to actually get implemented at a wide scale.]

  • Jim Shillady

    Great product. As a retired ice harvester sales rep I know this is a viable approach to off peak storage for on peak cooling. Should sell big time. Circulating refrigerant and the modular retrofit approach – if the mating existing fan can handle or be fitted to handle the drop thru the added refrigerant coil, all is well. Structural eng will say yes the roof will cave or not. How far can you practically, pump the refrigerant?

    Jim SESCo (Shillady Engineered Systems Co.)San Diego Ca.

  • Marc Marton


    SCPPA put Ice Bears through field trials for an extended period before committing to 53 MWs worth. This isn’t a test or a trial, but a true strategy for SCPPA member utilities to shave peak demand and reduce emissions. Let me know if you’re interested in speaking with someone from SCPPA.

    • Got it. Thanks, yes, great. I’ll correct my story. (These things live in cyberspace forever…)

  • Marc: The idea of the grid using distributed storage on a large scale test like this is a “trial” – that is what I meant by a trial or pilot. In case others are not clear, I’ve bolded those mentions.

  • Marc Marton


    You’re mistaken on all accounts.

    Ice Bears are not evolving. They’ve been in use for many years and are proven.

    The Glendale project is a full-fledged installation, not a “trial.” SCPPA will install thousands of Ice Bear storage systems throughout it’s member utilities without any government subsidies.

    And Ice Bears can be installed safely on roofs, usually without modification to the building. They do receive ground installs if that location is deemed to be a better alternative.

  • Greg R

    This is a great idea. A company called ELCAL Research has developed a system using off peak electrical, wind or solar(both PV and ;glycol based panels) to heat and cool buildings except there phase change material(water like substance) freezes at 78 degrees enabling them to heat both a buildings hot water and the building itself. There system works and it will be economical. check them out at elcalresearch.com

  • juangault

    Well, this seems to be a very good idea on the surface. But I think this is a one of those evolving technologies that is growing on the steroids of government incentives. In the early years of wind generation, and like Jojoba farming, excessive tax incentives change the financial landscape and resulted in unrefined prototypes being brought too early to market.

    Part of the reason we won WW2 is the “kiss” principle. Keep it simple, stupid. Solar panels belong on the roof, where it’s harder to graffiti them, and ice storage belongs under the parking lot, where they won’t crash through the roof. Solar panels generate their power when it’s needed for A/C. They weigh a lot less. This idea of loading ice on the roof could work pretty well in Colorado, where snow loads and tornado winds have forced the builders to ante up on the cost of making the roofs stronger. But California has earthquakes, and I wouldn’t want to work underneath a ton or two of ice, retrofitted on a building not made to carry it. The first accident that leads to a lawsuit in this sue-happy state will probably set back any financial savings 5 years. The people deciding this thing are in it for the money, not for a sustainable, low carbon future.

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