Production of Fresh Water by a Solar Still: An Experimental Case Study in Australia

Abstract

There is a scarcity of fresh water in many rural communities where solar stills can be used to produce drinking water at a minimal cost. These stills use solar energy, which is a sustainable form of energy, and hence this can contribute towards achievement of United Nations (UN) Sustainable Development Goals (SDG). This study aims to develop empirical models of a solar stills based on experimental data obtained at Werrington South, New South Wales, Australia. Two solar stills were used in the experiment, a conventional design (Con-Still) and a con-still modified with adding extra thermal mass inside the still (mod-still). Regression analysis was adopted to develop prediction equations using Pi (productivity in L/m2/day) as the response variable and ambient temperature (Ta), sky temperature (Ts19), global radiation (Gh), and wind velocity (W) as the predictor variables. The mean and median productivity values of the mod-still were found to be 17%, and 22% higher than that those for the con-still. The proposed mod-still can be further improved and used in rural areas to produce fresh water from sea water and other forms of contaminated water.

Statistical Model for the Sizing of a Prototype Solar Still Applicable to Remote Islands

“…The market price of bottled water (less than 1 L), NTD 18, for Dongji Islet (estimated based on a prince range of NTD 13-23 and the distance from the neighboring town of Magong in the Penghu Archipelago), crude sea salt (NTD 23 per kg), and an estimated market penetration rate of 60% was applied in Equation (19). The capital cost (C capital ) was evaluated using the formula: (23) where C equipment represents the cost of fabrication as previously determined by [1] and C installation represents the cost of installation on Dongji Islet, which is estimated at 15% of C equipment based on the remoteness of the Islet.…”

“…Such models vary in accuracy, complexity, costs, time for development, technology, and technical expertise. Common approaches taken by researchers to model the productive performance of a solar still include thermal [9][10][11][12][13][14], intelligent [15][16][17][18], and statistical modelling [19][20][21][22][23][24][25][26][27][28][29]. For the purpose of this study, the statistical modelling approach was adopted.…”

“…For the purpose of this study, the statistical modelling approach was adopted. To estimate the productivity of a solar still, statistical models used by previous researchers utilized, in some instances, meteorological factors only [19,28], operational factors only [20], or a combination of meteorological, design, and operational factors [21][22][23][24]26,27,29] as predictor variables as outlined in Table 1. Additionally, a variation of linear, non-linear, and exponential regression models have been based on the stepwise technique.…”