An Egyptian research group has invented a small solar refrigerator which does not use refrigerant gases or moving mechanical parts to cool.
The refrigerator uses thermoelectric cooling, based on the Peltier effect.
The refrigerator is one of the essential appliances in homes, used to keep food fresh, thus avoiding food waste. There are many tips for reducing the electricity consumption of these devices, and some alternative proposals without electricity, such as underground refrigerators or those that take advantage of night temperatures. However, these solutions are not always practical in everyday life.
The group of scientists from the National Research Center of Egypt and Helwan University, in Cairo, has developed a mini-refrigerator which, in addition to being powered by solar panels, uses semiconductors for cooling.
In other words, this innovative refrigerator does not require refrigerant fluids to produce cold. It employs a solid-state refrigeration technique, known as thermoelectric cooling, which uses the Peltier effect to create a temperature difference in materials. In this system, special components called Peltier modules are used, consisting of two conductive materials connected to each other. When you apply an electrical current to these modules, one side of the module cools, while the other side heats. This solution not only eliminates conventional refrigerants, but also requires no moving parts for operation.
To describe this work, the researchers published an article in the journal Scientific Reports, titled: “Optimizing COP by RSM and MATLAB model of mini refrigerator based on thermoelectric units driven by solar photovoltaic“. Their system featured an outer wooden compartment and an inner stainless steel compartment, separated by thermal insulation foam.
The experimental refrigerator was tested by simulating different levels of sunlight and various powers of solar panels, using an energy source with adjustable voltage between 4 and 14 volts. Next, they put water in the box to test the cooling capacity. After about 45 minutes, with four Peltier modules powered at 10 volts, they observed that the water temperature had dropped by 4.5°C, from 30.9°C to 26.4°C.
Promising results that give hope for solar refrigerators for all homes.
