Design of energy efficient low power PV refrigeration system

Stand-alone PV systems have shown to be reliable and cost effective for cooling & refrigeration and have attracted the users. For a specific application with an estimated requirement of cooling, low power refrigeration system using PV modules (2 modules each of 36 solar cells) has been designed, fabricated and developed. In this paper, results of the I-V characteristics for the solar panels used have been presented and discussed. Charging and discharging processes for the battery including the voltage as a function of specific gravity and time have been carried out. All the results are significantly encouraging and hence test results of our system using the charge controller and DC powered refrigerator are presented. The paper also deals with our experiences encountered including the successful operation of the refrigeration system during off the sunshine hours continuously for 6 hours. The calculations of the specific cooling costs show the promising economic effectiveness and reliability of the designed PV refrigeration system. Keeping in view of the technical performance and economic parameter, it demonstrates that this small-scale technology can contribute to solving problems of cooling like small area refrigeration including the transportable and small cold storage container with integrated PV energy supply systems. These systems can be erected on or around a vehicle to obtain the cooling needs while on drives including picnics or especially in remote desert areas.