Is desalination really cheaper?
The majority of the worlds desalination plants are based on thermal distillation technology, which is able to desalinate large volumes of water. However, this technology is energy intensive and it is expensive to operate unless cheap or surplus energy is available. The Middle East, which enjoys low energy costs, is a large proponent of this technology. South Africas energy challenges do not bode well for energy intensive technologies though. Our hope lies in recent advancements in membrane technology that have made cost-effective desalination more of a reality. Past membranes could not process large volumes of water, but now these very thin, molecular sieves are able to process up to 300, 000 M3 per day. Based on the Department of Water Affairs and Forestrys free daily allowance of 25 litres per person, this is enough for approximately 12 million people. Also, the process is less energy-intensive, hence the life-cycle costs are significantly lower than traditional thermal distillation
