BRUSSELS (Reuters) - European leaders discussed the region's reserves of shale gas at a summit on Wednesday, but the prospect of the continent enjoying a U.S.-style shale boom that drastically cuts energy costs remains elusive.
Arriving at the summit, British Prime Minister David Cameron, whose government is advancing plans to exploit his country's shale gas deposits, said Europe could not afford to be left behind as the world scrambles to develop the resource.
He drew a comparison with the United States, where years of extraction, using a much-criticised process of hydraulic 'fracking', has delivered record-low gas prices for consumers.
"We mustn't be left behind in the global race," Cameron told reporters. "Europe has 75 percent of the United States's shale resources, but America is drilling 100 times faster than Europe.
For the European Union, there is no broad-based agreement on how shale gas should be developed, with some of the EU's 27 member states completely opposed to any exploration, others in two minds and a few fully committed to it.
At the same time, the European Commission says environmental standards must be maintained, and potential investors in shale gas have to consider Europe's more complex land-ownership and mineral extraction laws.
Other issues include the greater depth of EU shale gas reserves compared with the United States, which can increase drilling costs by a factor of three, analysts say.
Of EU nations, the eastern states of Poland and Lithuania are among the keenest to cut their reliance on imports of natural gas from Russia by developing shale gas of their own or importing it in liquid form from the United States.
While gas prices in the European Union are roughly four times higher than in the United States, analysts say U.S. prices will inevitably rise as production costs can exceed income from the gas.
Rex Tillerson, CEO of the largest U.S. natural gas producer, Exxon Mobil Corp, said: "We are all losing our shirts today," when talking about natural gas prices, a comment that hints at the double-edged nature of the asset.
European Council President Herman Van Rompuy said Europe needed to tap all resources, but it was up to individual member states to make their own energy choices.
"Yes, this includes shale gas which could become part of the energy mix for some member states, perhaps less for others," Van Rompuy said. "Soon Europe could be the only continent to still depend on imported energy. Households feel the weight of high prices, industry finds it hard to compete with foreign firms."
Apart from shale gas, summit documents also focus on completing the single European energy market.
In theory, better cross-border connections can help to lower prices and increase security of supply, but more than half a century after the founding of the European Union, the single energy market is still incomplete.
For many, shale gas is far more unrealistic. Green politicians and environmental campaigners say it is a dangerous distraction from the pursuit of carbon-free energy and energy efficiency, which they say is the best way to free the European Union from expensive fossil fuel imports.
(Additional reporting by Ethan Bilby, Adrian Croft, Martin Santa; editing by James Jukwey)