Greenpeace releases report on coal and water use in South Africa
Submitted by: Jonathan Ramayia, Thursday, October 25, 2012
A new report released by Greenpeace Africa has provided explanation on the link between the use of water and energy production by South Africa’s sole energy utility Eskom. The report, Water hungry coal argues that South Africa is on a dangerous path to increased water scarcity because of the government’s decision to continue obtaining its power from coal. The report highlights South Africa’s well known predictions for water shortage in the coming decades and names Eskom as one of the main players who needs to change their mode of production to prevent severe water shortages in the future.
Water usage in coal
Like many industries, including mining and agriculture, water is an essential input into the production of energy from coal. Large amounts of water are needed at two stages of production in order for electricity to be delivered to Eskom’s customers across the country.
The first stage is at the coal mine, where impurities on the stock of coal are removed. In addition to this, water is used in dust suppression to prevent excess coal dust being released into the air at mine sites and when coal is transported over long distances.
The second stage takes place at the coal-fire power station where large amounts of water are needed for producing steam and for cooling. When coal is burnt it produces either hot air or steam which drives the turbines in order to produce electricity. Greenpeace notes that 60% of the heat/steam from coal combustion is lost as waste heat. The waste heat needs to be removed and is done so by using large quantities of water.
The report calculates that Eskom uses slightly more than 10,000 litres of water per second during the production of electricity from its 13 operational coal-fired power stations in the country. In total the report estimates that the country’s coal-fired power generation uses 4.84% of the national water supply.
“South Africa is a water scarce country, but every step in the chain of using coal to produce electricity pollutes and consumes vast amounts of water. Together with coal mining, burning coal for electricity generation has a number of serious implications for both water quantity and quality, and it is undeniable that coal-fired electricity generation is highly water intensive compared to renewable energy technologies such as wind and solar PV”, says the report.
South Africa a net-importer of water
South Africa’s water resources have historically been a major developmental constraint on the country, with the country receiving on average of 497mm of rainfall annually, much lower than the world average of 860mm as noted in the report. As a result, much of the water the country demanded by agriculture, urban centres and industry is obtained from neighbouring countries such as Lesotho. The report notes that through the years, the water shortage has been solved by technological innovation and engineering with little consideration of the surrounding socio-economic situation of the region or the environment.
With over 98% of South Africa’s fresh water already allocated, the report warns that further coal expansion could result in problems both at home, with government unable to deliver water to low income communities, as well as across borders into the SADC region where growth in other countries could see conflict over water resources. In addition, water scarcity will also be exacerbated by changes in the climate, where predictions for South Africa show erratic rainfall as well as droughts in the western half of the country.
Dry cooling for Medupi and Kusile
‘Direct dry cooling’ is a technology that is said to use less water in the cooling process described above and keeps the cooling water in a separate closed circuit, so that cooling occurs through heat transfer instead of evaporation achieved through the use of water.
Greenpeace acknowledges Eskom’s use of ‘direct dry cooling’ in four of its existing coal-fired power stations in reducing water consumption but notes that it is still an expensive and more energy consumptive technology and argues that is still less favourable than renewable energy options.
In South Africa, four coal-fired power stations currently use dry-cooling technology and both Medupi and Kusile will also employ dry cooling.
Greenpeace labels the country’s Renewable Energy Independent Power Producers Programme (REIPPP) as ‘greenwashing’ and that it is not a concerted enough effort to pursuing renewable energy in the country. The report compares the use of water in the upcoming Kusile Power Station with the use in two other renewable energy options as shown in the table below:
Water use (m3 per MWh produced)
Dry-cooling coal-fired power station (Kusile)
Concentrated solar power with parabolic trough (dry cooling)
Greenpeace recommends in the report that the South African government should immediately prioritise renewable energy production over coal-based production and that no further investment should go into coal.
Quick Greenpeace report facts:
- 497 mm is South Africa’s average annual rainfall, 860 mm is the world average
- 1 million households in South Africa are without the minimum of 25 litres of water per person per day
- 98% of South Africa’s fresh water is already allocated
- 93% of South Africa’s electricity comes from coal
- 62.3% was Eskom’s contribution to South Africa’s total carbon emissions in 2011
- 10 000 litres of water per second is used in energy production by Eskom
The report is available for download on the Greenpeace website.
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