Older power stations like the Camden Power Station in Mpumalanga rely mainly on water-intensive cooling technologies. File photo: Karen Sandison

 

Durban - 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 from 1966) have increased Eskom’s water use significantly and this will be unsustainable unless they are decommissioned as soon as the new Medupi and Kusile power 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 is compounded by the fact that power stations are located deliberately next to coalfields to reduce transport costs, yet coalfields are 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 Prof 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% of Eskom electricity is generated by burning coal, which also requires large volumes of water for cooling power plants.

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

Though the reactivated Eskom plants had helped to keep power flowing during the current crisis, the magazine said it was vital that these older power stations be shut down as soon as Medupi and Kusile began to feed the national grid.

If these reactivated power plants were decommissioned timeously, this could save up to 4 000 million litres of water each year.

Pouris told the magazine that the latest study also raised several fresh questions on the need to produce electricity using more water-efficient technology.

Shutting down the recommissioned plants would provide only a temporary solution to the impending, longer-term water shortage.

“I think that the 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,” Pouris told the magazine.

Last week the Department of Co-operative Governance and Traditional Affairs announced water rationing in the province, with the northern parts of eThekwini and the iLembe district the most seriously affected. Water levels in the Hazelmere Dam are at crisis level, with many farmers losing crops and animals.

The Mercury