Imagine how much electricity is required to sustain a supermarket with numerous rows of refrigerators and hundreds of lamps that light up the huge space. Statistics show that big supermarket chains use around ten times the energy of a normal household.
Now a new concept developed by researchers at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany, gives the opportunity to supermarket operators to cut energy use by as much as 25%.
The idea was developed in collaboration with property developers, manufacturers and the research team. As stated by Nicolas Réhault, Group Leader at ISE, the aim is to reduce energy consumption by focusing on the cooling systems.
In order to maintain the quality of various foods, the temperature of freezer-systems should be maintained at -25 degrees Celsius, for fish and meat, or 4 degrees for cheese and sausages. The practical method that is generally adopted, is the use of plug-in freezers, which keep the required temperatures, while heating up the store at the same time.
The proposed innovation combines all cooling points into a central refrigeration system. Instead of releasing the heat into the store, it is channeled via a three-stage recooling system. In winter the heat is recovered by the system through a heat exchanger to warm up the store, while residual heat is channeled via a gas chiller and a geothermal pump in the surrounding area.
The heated water, produced by the process is then pumped into the ground and the heat is dissipated, allowing the water to cool and is fed back into the system.
If this concept is applied, freezers and chillers will only require half of the electricity they usually need. Boilers and ventilation systems used for heating will no longer be required, because the space will be warmed up by the waste heat. This means that the ventilation will only be used to supply fresh air, which brings down the energy consumption by a third.