The ice battery (Ice Battery System) is a solution created through close cooperation between the companies: Rawlplug and Wentima and specialists from the Wroclaw University of Technology. It is an innovative cooling energy accumulation system using phase transformation and waste heat.
Take energy when it pays off the most
The ice battery operates on a daily cycle of charging and discharging. It takes in electricity at night, operating at the lowest rates, and discharges during the day, thus allowing the peak of energy consumption to shift from day to night, or when there is the highest and lowest demand for energy.
The modular system allows the implementation and expansion of the ice battery within both new and existing installations.
- The battery enables more efficient energy management. It is discharged when energy consumption and price are highest. Thus, the device acts as a stabilizer, an energy fuse that allows us to adjust energy consumption to tariffs, since most companies pay more for energy during the day than at night," one of the consultants of the invention, Dr. Piotr Piechota of the Department of Mechanical and Energy Engineering at the Wroclaw University of Science and Technology, tells Nauka w Polsce service. - The ice battery system allows for more efficient - and thus also greener - energy management by operating on peaks and off-peaks
Ice Battery: how does it work?
The Ice Battery reservoir contains cores of water solution and radicals that accelerate crystallization. When storing refrigeration energy, such as at night when energy demand is lower, the cores, surrounded by cold glycol, freeze the refrigerant. The refrigeration energy stored in this way can then be used during the day.
An ice battery, however, is not just a store of refrigeration energy. It is a complete system that also stores heat, and is able to optimize energy intake and consumption cost-effectively, based on the lowest electricity rates.
Michal Wojsa, Wentima Company
Sunday energy from the sun
From one unit of electricity, the ice battery is able to produce and store three units of cooling energy and more than three units of heat, which is expelled by the chiller during freezing.
With the ice battery, Rawlplug is already using surpluses from photovoltaics. Among other things, they are stored on Sundays, when energy demand is lower, and given back on Mondays, in the form of cold needed for production processes. In this way, the Wroclaw plant is able to obtain as much as 56 days of free energy per year, assuming that surpluses are recorded only on Sundays.
Thanks to its modular design, the Ice Battery system did not require any reconstruction of the infrastructure in Wroclaw. In order to achieve the expected effects, it was enough to plug it into an already existing installation.
With concern for ecology
Savings and increased efficiency are the main, but not the only, advantages of the Ice Battery System, which is also of great importance in terms of environmental protection.
Our ice battery consists of water, plastic and steel. We don't have to worry about its disposal not only because of its acid-free composition," says Michal Wojsa. - This system simply does not wear out. Its efficiency does not diminish over time, and the only thing to pay attention to during use is the level of the water solution.
For the Science in Poland service, the idea of the Wroclaw-based company was reviewed by Prof. Tadeusz Bohdal, head of the Department of Power Engineering at the Koszalin University of Technology.
- Detailed solutions that improve the energy efficiency of these processes can be regarded as novelty. However, the authors do not provide them, explaining it as patent secrecy. Reversing processes always involves energy losses. The reported gain of 20 percent is probably due to energy prices at different times (night and day tariffs), the scientist says. - To sum up, one can say: an old idea, a new solution. The proposed method can bring significant benefits on an industrial scale, but there must be a company that uses significant amounts of cooling power.