Thermal Energy Storage (TES) Program Update (6-2012) Details
REU's thermal energy storage (TES) program utilizes Ice Bear intelligent distributed energy storage systems that work in conjunction with commercial direct-expansion (DX) air-conditioning systems, specifically the refrigerant-based, 4-20-ton packaged rooftop and ground mounted systems common to most small to mid-sized commercial buildings.
Ice Bears store energy at night, when electricity generation is cleaner, more efficient and less expensive for REU, and the units deliver that energy during the peak of the day to provide cooling to the building.
Daytime energy demand from air conditioning – typically 40-50% of a building’s electricity use during peak daytime hours – can be reduced significantly. In kilowatts, each Ice Bear delivers an average reduction of 7.2 kW of source equivalent peak demand for a minimum of 6 hours daily, shifting 32 kW-hours of on-peak energy to off-peak hours.
Think of the Ice Bear as a battery for the air conditioning system. Only this one is cooler, because it’s made out of Ice.
At its most basic, the Ice Bear consists of a large thermal storage tank that attaches directly to a building’s existing air-conditioning system.
The unit makes ice at night, and uses that ice during the day to efficiently deliver cooling directly to the building’s existing air conditioning system.
The Ice Bear energy storage unit operates in two basic modes, Ice Cooling and Ice Charging, to store cooling energy at night, and to deliver that energy the following day.
During Ice Charge mode, a self-contained charging system freezes 450 gallons of water in the Ice Bear’s insulated tank by pumping refrigerant through a configuration of copper coils within it. The water that surrounds these coils freezes and turns to ice. The condensing unit then turns off, and the ice is stored until its cooling energy is needed.
As daytime temperatures rise, the power consumption of air conditioning rises along with it, pushing REU's electric system to peak demand levels. During this peak window, for REU, typically from 2:30 pm to 6:30 pm, the Ice Bear unit replaces the energy intensive compressor of the building’s air conditioning unit.
The Ice Bear, fully charged from the night before, switches to Ice Cooling mode. The Ice Bear uses the ice, rather than the AC unit’s compressor, to cool the hot refrigerant, slowly melting the ice as it travels through a series of copper coils. A small, highly efficient pump pushes ice-cold refrigerant through a modified Ice Energy LiquidDX® evaporator coil installed in the conventional air conditioning unit.
The Ice Cooling cycle lasts for at least 6 hours.
Once the ice has fully melted, the Ice Bear transfers the job of cooling back to the building’s AC unit, to provide cooling, as needed, until the next day. During the cool of the night, the Ice Charge mode is activated and the entire cycle begins again.
For the past seven years, REU has been partnering with local business and building owners installing Ice Bear systems throughout the Redding community. REU's Ice Bear program is designed to provide commercial building owners with both the Ice Bear unit(s) and installation incentives. For example, a local movie theatre recently expanded. As part of its expansion project, the owners in partnership with REU, incorporated Ice Bears into the theatre's mechanical system design. REU provided multiple Ice Bears to the project, and reimbursed the owners for 100% of the installation cost of the Ice Bears. All Ice Bear installations are thoroughly evaluated by REU, Ice Energy and both structural and mechanical engineers. The decision to proceed with an installation of Ice Bears or not, is at the sole discretion of REU.
Watch the Ice Energy video for more information.
For more information about REU's successful Ice Bear program, please contact Dave Jackson at 530.339.7240