Characterization and monitoring of a self-constructible photovoltaic-based refrigerator

At present, in the developing countries, the power grids do not reach every small town and, even when they do, they are not reliable. For this reason, preservation of food and medicines is a sensitive issue for a large number of people. This work introduces the characterization of a new, self-constructible refrigerator, powered by photovoltaic (PV) energy, suitable for the preservation of food in rural villages, with a specific focus on Africa's tropical-equatorial belt. A thermally-insulated envelope, equipped with thermal energy storage, has been designed to be built on-site, by using local materials, and assembled with technical components (direct current (DC) compressor, heat exchangers, photovoltaic module). The monitoring activity presented in this work was carried out on a first prototype of the system and enabled the validation of numerical simulations, aimed at assessing its appropriate operability under laboratory conditions. In particular, the work demonstrates that the basic module of the refrigerator, with a net capacity of 250 L and an ice storage of 12.5 kg, is able to maintain an internal temperature below 10 °C also in critical boundary conditions.