Alarm over water supplies as Eskom drains resources

DURVAN: Eskom’s battle to keep South Africa’s lights burning is also draining one of the country’s most critical resources – almost 4 000 million litres of extra water each year.

A new joint report by the Water Research Commission and the University of Pretoria warns that mothballed Eskom power stations that have been reactivated in recent years to meet the power crisis are guzzling unsustainable volumes of water.

The new study, summarised in the commission’s latest Water Wheel magazine, suggests that three of the country’s oldest power stations (some dating back to 1966) had increased Eskom’s water use significantly, and this would be unsustainable unless they were decommissioned as soon as the new Medupi and Kusile stations come into service.

Unlike Medupi and Kusile, which use more modern dry-cooling technology, the older Camden, Komati and Grootvlei power stations rely mainly on water-intensive cooling technologies.

The extra water usage was compounded by the fact that power stations were located deliberately next to coal fields to reduce transport costs, yet coal fields were often located in water-scarce regions.

“The field of water-supply shortage is a hidden crisis. We already have shortages of water in areas of South Africa, but we have not seen many studies investigating the expected demand for, and supply of water,” said Professor Anastassios Pouris, of the University of Pretoria, who led the Water Research Commission study on water-use projections in the electricity sector until 2030.

The study notes that about 90 percent of Eskom electricity is generated by burning coal, which also requires large volumes of water for cooling power plants.

Although some of the water was recovered from cooling towers, significant volumes were lost to evaporation.

Pouris told the magazine that the latest study also raised several questions on the need to produce electricity by using more water-efficient technology. Shutting down the recommissioned plants would provide only a temporary solution to the impending, longer-term shortage.

“I think that most critical finding of this study is for the government to recognise that if they are not going to support research, we will be in trouble again, in the same way that we are in trouble with Eskom now.”