Shale gas: clean fossil fuel or unwanted distraction?

Shale gas drilling in Fayetteville, USA

Shale gas drilling in Fayetteville, USA. (Source: BHP Billiton)

By John Parnell

The recent shale gas discovery near Blackpool in the UK was greeted with cautious optimism from certain sectors of business, and vehement opposition from environmental groups.

Conventional gas may be cleaner than coal, but how clean is shale gas and is any prospective fossil fuel clean enough?

RTCC speaks to three parties recently involved in a UK government Commons Select Committee investigating shale gas, The British Geological Survey (BGS), WWF-UK and pro-shale gas campaigner and PR officer, Nick Grealy.

“The UK only needs a finite amount of generation capacity,” says Jenny Banks, energy and climate change policy officer, WWF-UK. “New gas capacity lasts for up to 30 years. There is less incentive for business to invest in renewables if the market is over supplied. If there is ample gas in the generation mix there may be a temptation for government to scale back support for renewable sources.”

Aside from stifling the expanding economy built around renewables, Banks also believes that removing more carbon from underground storage will make emissions targets unattainable.

“To keep climate change within two degrees, less than 20% of the known conventional reserves can be burnt. Once you include growing fossil reserves such as shale gas, the picture is even starker,” says Banks. “The world has a finite and rapidly dwindling carbon budget left to spend. Exploiting more fossil reserves is totally incompatible with this scientific reality.”

Nick Grealy runs and works as a public acceptance and PR consultant for a number of energy companies, including Cuadrilla, the licensee of the find in Blackpool.

“I don’t think the environmental groups have anything to fear about it replacing renewables,” says Grealy. “To have an unrealistic expectation that renewables can replace coal or gas is dangerous. The true climate crime would be to continue to burn coal in the place of plentiful, worldwide, economically and environmentally sustainable supplies of gas.”

The shale gas versus coal argument is highly complex and the two most high-profile scientific papers (one on each side of the debate) have both been criticised. One issue that both sides agree on is the need for more detailed scientific data related to the composition of resultant emissions and potential methane loss during drilling.

In the meantime, Grealy argues that the drilling firms have an incentive to reduce leaks as they don’t get paid for the methane that escapes.

The case for gas appears to have two main prongs. The first is to replace coal with gas, which he says is half as dirty. Much of the UK’s emission cuts since 1990 are attributed to gas replacing coal-fired power plants. WWF’s Banks has already expressed opposition to that argument.

Grealy takes up the second argument, one that receives less media coverage.

“Between 30-40% of the UK’s oil is consumed by 10% of the vehicles on our roads. Buses, lorries, commercial vehicles, taxis and so on. Converting these to liquefied natural gas (LNG) from diesel would have a big impact on emissions and also air quality,” says Grealy. “Tuk-tuks in Bangladesh were converted to LNG with great success.”

With much of this freight and fleet traffic fuelling-up along motorways or at central hubs, Grealy claims that a network of 50 LNG fuelling stations would support a UK-wide national transport network.

He argues that LNG should be the immediate focus of reducing transport-related emissions rather than electric vehicles.

Cuadrilla has estimated its find at 200 trillion cubic feet (tcf), 10-30% of which will be recoverable. More information is required before the company can offer a more precise recovery rate.

“The uncertainties in the assessment of a shale gas field are potentially very large,” says Nigel Smith, subsurface geologist and geophysicist, BGS. “The main variables are the presence and thickness of high carbon content shale at the correct level of maturity and the measured gas content of these shales. These can all vary substantially within any given licence area and between the different formations.”

Grealy says the 3000ft thickness of the Blackpool find is key to its scale. The shale gas seam in Pennsylvania is around 200ft. BGS’ Smith sounds a note of caution for those that scoff at the Cuadrilla figure.

“It’s perhaps sensible to remember that after several dry wells, the Falklands offshore was written off as unprospective, yet Rockhopper Exploration has made a discovery there.”

Grealy reveals that Cuadrilla will be sinking five more wells centred over its Blackpool license area to help it refine its data.

Banks is not convinced that gas has a role to play in the UK, irrespective of the scale of any new finds.

“The International Energy Agency’s report examining whether we are entering a golden age of gas modelled a scenario where there is a stronger move to gas as a result of the new shale gas resources. There is virtually no climate change benefit and we end up with at least 3.5 degrees of global warming. Although gas replaces some coal in this scenario, it also replaces low carbon generation,” says Banks.

This brings the argument full circle. New gas discoveries could promote cleaner energy production. Or they could give governments and big business a low-cost crutch to meet demand, while hobbling away from emissions targets.

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