Design And Implementation Of Solar Photovoltaic Based Power Supply For Portable Mini-Refrigeration System Utilizing Peltier Effect

Abstract

In medical service, provisioning vaccination plays an important role in immunizing adults and children by triggering the body to produce antibodies. Most vaccines are heat and temperature-sensitive products. Therefore, effective cold storage systems are required to store and transport vaccines. Rural areas in Ethiopia do not get sufficient vaccines because most vaccines are produced and temporarily stored in cities. Nowadays, several kinds of vaccine storage systems are available commercially. Thermoelectric-refrigeration cooled storages are an innovative and alternative kind of vaccine storages. These storages are rugged, reliable, quiet, and require less maintenance. Peltier module is an excellent thermoelectric device as it is energy-efficient and has better performance features under different working conditions. But the low efficiency and large cooling time is still an issue. To overcome this issue, it has to improve the coefficient of performance (COP) of the module. With this consideration, an improved vaccine storage system consisting of Peltier modules, solar modules, DC-DC buck-boost converter, temperature regulation system, and a back-up battery is presented. To achieve this, a cooling load, a Peltier module, a solar module, and a DC-DC converter are modelled mathematically. For the implementation, the selected environment has a 58.6905W cooling load, minimum solar insolation of Gmin 5000 Wh/m2/day, and has a maximum ambient temperature of 40.38oC. So, the 94.138W electric power consumed has been designed and simulated using MATLAB Simulink and HOMER software. The designed solar panel a 45W, 10AH backup battery, and DC-DC converter lead to achieving the COP is 0.692 of the developed system and drop 11oC of temperature within 21.5 minutes. The cost to develop this system needs an overall net present cost (NPC) of $120.04 and a cost of energy (COE) of $0.073/kWh. The COE is feasible as it is comparable with the national tariff. The prototype of the proposed system excluding the solar panel and a back battery has been developed. In general, this research work’s for improvement of cooling time with a better COP.