/ 18 August 2011

The shale lottery

Shale is sedimentary rock in which its layers function as strongrooms for a gas primarily made up of methane. Since this gas apparently burns about 50% cleaner than coal, it should be welcomed — in light of South Africa’s aim to reduce its carbon footprint, Maarten de Wit, an academic at Nelson Mandela Metropolitan University, writes in the South African Journal of Science.

This gas offers a bridging fuel towards renewable energy sources such as solar, wind and wave that are sustainable and completely clean future for energy.

To understand what benefits South Africans might reap in this shale lottery, one need only look at the United States, where shale gas has become the “it” fossil fuel.

The Marcellus shale, which stretches from Tennessee to New York, an area about one-third the size of the Karoo, may hold enough gas to heat US homes for two decades. It has been predicted, De Wit says, that shale gas will account for about 46% of natural gas in the country by 2035.

But environmental activists have pointed to many examples of fracking in the US where borehole water supplies have become contaminated.

The fracking process requires millions of litres of a water-based, sandy, chemical cocktail to be pumped into the shale rock at high pressure to open up fissures, from which the gas can be extracted.

The Karoo is one of the most water-starved regions in the country, and anti-fracking campaigners say that fracking could contaminate the region’s precious ground water with chemicals.

Add to this the habit of energy companies to be cagey with their information and financial dealings, and you have legitimate concerns, De Wit said in his article.

However, De Wit says in his article that fracking methods have been refined over the past few years and there are now technologies and best practices that can minimise the risks of shale gas development, including using alternatives to harmful chemicals in fracking fluid, and using the highest quality materials to make sure that no fluid contaminates groundwater sources.

With reliable independent policing, De Wit maintains, shale gas exploration can go ahead relatively safely.