Method to evaluate conversion efficiency of single basin solar desalination stills for field applications

Abstract

We formulate and apply a solar radiance based model to determine the efficiency of basin solar stills. Optimization of different solar still sizes and designs normally requires hourly monitoring of the various stills. This would typically require data logging thermal sensors or regular temperature logging throughout the day, which may be prohibitively expensive for working solar desalination installations, especially in Developing Nations, where the solar stills may either be of disparate sizes and types and sometimes in use over a wide area. This model requires simple data collection tools; a recording solar incidence meter, a digital mass scale to asses still output and a handheld infrared thermometer. This data is usually gathered only one time per day, which allows for long term studies by non-project personnel. We find that this solar radiance model allows for direct comparison between stills of different sizes and configurations. This work covers the evaluation model, rather than the stills themselves.