.

COAL, gas and nuclear energy all met SA’s need for low capital and operating costs, security of fuel supply and ability to reduce global carbon emissions, experts from each sector argued on Tuesday.

SA’s existing and planned coal and nuclear power investments have aroused intense criticism on the grounds of affordability and environmental damage. Eskom’s two large coal-fired power stations at Medupi and Kusile are late and over budget while the government’s decision to invite bids for 9,600MW of new nuclear energy has not been widely canvased with the public.

At a debate on the merits of different energy technologies at research group Afriforesight’s Commodity Conference on Tuesday, Shell SA chairman Bonang Mohale said SA needed to diversify its energy sources to meet a gross domestic product growth target of 7% a year to absorb all its job-seekers.

"The case for gas is compelling," he said. "It is abundant, emits half the carbon emissions that new coal-fired power stations do, and it is affordable. To build a closed-cycle gas turbine takes three to six years depending on its size and complexity, compared with nine years for Medupi or Kusile."

On concerns about the effect of fracking for shale gas in the Karoo on scarce water resources, Mr Mohale said fracking technology was 60 years old and wells were now designed to ensure there was no water contamination. In the Karoo, Shell SA proposed to use brackish water deeper than existing drawdowns, or even salt water.

Nuclear Africa CEO Kelvin Kemm said concerns about nuclear safety were misplaced. No one died as a result of radiation leakage at Fukushima in Japan and fewer than 60 people were killed as a direct result of the Soviet-era meltdown at Chernobyl. Both of those were old-style reactors, without the safety features of the new plants.

Nuclear Energy Corporation of SA executive Ruby Ramatsui said the cost of managing nuclear waste was already in the price, but the cost of CO² emissions was not in the price of coal-fired power. Although the upfront costs of nuclear reactors were high, the biggest element of those costs was the interest rate charged on financing, he said.

Mr Mohale said it could take about 36 months to build a gas-fired power station, at a 10th of the cost of coal-fired power stations. Dr Kemm said if SA began building now or next year, the first nuclear reactor could start to deliver power in 2023.

"If we have labour problems, that is where money will be lost," he said. "We have to take control of the build process and not let it fall into the hands of warring labour factions."

Exxaro executive Mervyn Govender said despite mining coal for 140 years, SA still had about 170 years of coal in the ground. Coal was cheap to mine and coal-fired power stations were relatively easy to build. CO² emissions could be managed by using clean coal technologies and concerns about SA’s increasing number of ash dumps could be addressed by finding alternative uses for fly ash.

XMP Consulting analyst Xavier Prevost said coal was the only source of cheap and reliable power in SA, although for long-term security of supply the country needed independent coal-fired power operators.

Despite China’s move to reduce air pollution from coal-fired power, it was still generating large quantities of energy from the same quality of coal through using modern, supercritical technology in power stations, Mr Prevost said.