Energy demands of off-grid ice production and refrigeration

Refrigeration and freezing projects are becoming increasingly relevant in developing countries as the need for temperature-controlled food and medicine becomes more ubiquitous. Ice can be locally produced in remote areas using renewable energy powered freezers; however, minimal data exists in the literature about the time and energy requirements needed for this process. This introduces significant challenges in sizing the energy source required to power an off-grid ice making operation, as cooling the water drives the power consumption of the freezer. In this paper, a basic model is developed which calculates the time taken to freeze a quantity of water and experimental data is collected to validate the model. Both analytical and experimental techniques are used to examine how the freezing process is affected by parameters such as opening and closing the freezer door, varying the quantity of water being frozen, and the local atmospheric conditions. These results are related back to the energy consumption of the freezer compressor and are compared with field data from freezers and refrigerators installed in energy kiosks in Zambia. With this newly developed model, more accurate load profiles can be established for designing energy kiosks which support off-grid ice-making operations in developing countries.