Solar-Based Water Purification System for Urban Areas: A Case Study

Abstract

Water is a necessity for the survival of all living beings. Even though 71% of the Earth’s surface is water, there is still an acute shortage of potable water in many countries, as approximately 97.5% of Earth’s water is saltwater in the oceans and only 2.5% is freshwater in groundwater, lakes, and rivers. Thus, access to clean drinking water is a major issue that needs to be tackled immediately and efficiently. Currently, existing technologies for water purification such as multistage flash, multiple effect, vapor compression, reverse osmosis (RO), ion exchange, electrodialysis, and capacitive deionization (CDI) require a lot of energy, leading to environmental pollution caused by the consumption of fossil fuels. It is also found that 70% of water supplied as input to these technologies is wasted, while methods such as RO remove important minerals, and hence, World Health Organization (WHO) standards do not deem this fit. The desalination of saline water using solar stills is an effective solution to overcome these problems. Solar energy is abundant, everlasting, economical and does not cause emission of greenhouse gases. Combining this worldwide availability and inexhaustible nature of solar energy with a desalination process, a water purification system is designed and operated. This paper proposes the design and application of a water purification system which will be beneficial for localities such as residential buildings and bungalows in densely populated cities where the rise in energy consumption has led to an increase in the carbon footprint, reduction in electric power supply, and higher energy costs along with the depletion of fossil fuels and other exhaustible energy sources. This design can be further modified and installed in arid regions and villages where grid electricity is not a feasible option to meet energy demands and water scarcity is prevalent.