Design and performance of a small-scale solar ice-maker based on a DC-freezer and an adaptive control unit

The presented work studies the use of a commercial freezer to produce ice efficiently by photovoltaic energy. An innovative control unit was developed which adapts the operation of the compressor to the availability of solar energy. The proposed solar ice-maker was analysed with the help of simulations and experiments for the location of Sidi Bouzid in Tunisia. A design methodology was presented to optimize the solar energy supply system for a target ice production of 12 kg ice per day. A PV array of 600 Wp and battery bank of 65 Ah capacity at 24 V were selected. The one-year simulation results showed that the ice-maker, which stores a total of 50 kg ice, is able to deliver the target ice production for 89% of the days of a typical year at the selected location. Additionally, a testing bench equipped with PV simulator and climate chamber was implemented in order to assess the ice-maker experimentally under two representative weather profiles. Under repeated unfavourable weather conditions, an autonomy of 5 days was concluded from the experiments.