Ice Bear Distributed Energy Storage
Ice Energy’s flagship Ice Bear system enables a powerful change in how – and more importantly when – energy is consumed for air conditioning.
The Ice Bear system is an intelligent distributed energy storage solution that works in conjunction with commercial direct-expansion (DX) air-conditioning systems, specifically the refrigerant-based, 4-20 ton package rooftop systems common to most small to mid-sized commercial buildings.
The system stores energy at night, when electricity generation is cleaner, more efficient and less expensive, and delivers 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 by the Ice Bear. Each Ice Bear delivers an average reduction of 12 kilowatts of source equivalent peak demand for a minimum of 6 hours daily, shifting 72 kilowatt-hours of on-peak energy to off-peak hours. In addition, the Ice Bear can be configured to provide utilities with demand response on other nearby electrical loads – effectively doubling or even tripling the peak-demand reduction capacity of the Ice Bear.
When aggregated and deployed at scale, a typical utility deployment will shift the operation of thousands of commercial AC condensing units from on-peak periods to off-peak periods, reducing electric system demand, improving electric system load factor, reducing electric system costs, and improving overall electric system efficiency and power quality.
The Ice Bear is installed behind the utility-customer meter, but the Ice Bear system was designed for the utility as a grid asset, with most of the benefits flowing to the utility and grid as a whole. Therefore Ice Bear projects are typically funded either directly or indirectly by the utility.
How It Works
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 roof top 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 the grid to peak demand levels. During this peak window, typically from noon to 6 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, slowing 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.
Adding Up to Less – Naturally Efficient Energy Storage
The Ice Bear system is designed to store energy off-peak and deliver cooling on-peak, while consuming less overall energy on the building.
Because it naturally compensates for inefficiencies in the storage/discharge cycle, thermal storage for air conditioning is unique among storage technologies. In fact, it is the industry’s first effectively “loss-less” energy storage solution.
Here’s how: When an Ice Bear unit is storing energy, it is operating an integrated high-efficiency AC condensing unit at night, when temperatures are low and thermal efficiency is high.
During the day, the opposite happens. When the Ice Bear unit is discharging its stored energy, it offsets the operation of the energy-intensive commercial AC condensing unit at times when temperatures are high and efficiency of the AC unit is at its worst.
This means the difference in operating efficiencies between the Ice Bear condensing unit and the commercial unit more than compensates for any inherent inefficiencies in the storage/discharge cycle common to other types of energy storage. In fact, when you factor in age, size, and high operating duty cycles, the Ice Bear condensing unit is clearly more efficient than the commercial condensing unit it is displacing.
Bottom line: The Ice Bear system reduces total net energy consumption for most buildings under virtually all operating conditions and installations.