School Reduces Peak Energy Consumption 20% with IceBank Tanks

June 12, 2015 By Linda Hardesty

UnknownThe Alamo Heights Independent School District (AHISD) in San Antonio, Texas, is using CALMAC’s ice-based energy storage technology to cool more than 325,000 square feet across five buildings on its high school campus. The school district, which already uses a 500 kW solar system and another five solar arrays totaling 400 kW to help power daily operations, needed to further reduce energy consumption during expensive peak demand hours.

Installing CALMAC’s IceBank tanks at its high school campus has allowed the district to store cheap nighttime energy from the grid in the form of ice that can then be melted to cool buildings during the day. As a result, the district has reduced peak energy consumption by more than 20 percent, despite an increase in square footage and student population.

The school had recently added over 40,000 square feet, but its energy costs per square foot have actually gone down with the installation of the thermal energy storage system. The school says the energy storage system has also allowed it to maximize the effectiveness of solar and allow the district to expand without the need for extra chillers.

2 comments on “School Reduces Peak Energy Consumption 20% with IceBank Tanks

  1. I’m a fan of ice as a thermal storage option as long as the economics support it. (I suggested it once for a manufacturing facility but the payout was not attractive).

    I’m hoping the school windows are not allowing infrared heating during daylight. If so, the building is needlessly being heated and this makes the a/c and ice inventory work too hard.

    In Texas, Solar Screens are popular and are one means of controlling heat gain. Other options include awnings, shutters, film, In’Filtrate, Solar Grates, trees, and others. All options reduce Utility demand during summer peaks. Solar Grates have savings similar to Solar Screens but use a different principle of operation. Screens are shading devices and are usually 80+% closed and block all light frequencies. Grates are 80% open. Sunlight impinging the Grate reflects selectively with visible light mostly reflecting into the room while 70% of infrared is blocked. This leaves the room cool and bright. For more details: http://hjcochran5.wix.com/solargrates101 .

    It makes no sense to allow a building to heat needlessly and then create novel ways to cool it back down again. Once the IR is managed, there is less ice required and the PV generated power can be redirected to more productive uses.

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