Vattenfall claims the carbon-capture plant is the first step towards CO2-emission-free power generation based on coal. The Swedish-owned company built the pilot project in eastern Germany where lignite mining and burning is the primary source of energy production.

The Jänschwalde power plant is a 1600-megawatt energy giant gobbling up more than 80 thousand tons of lignite every day. Located in the middle of the vast and barren coal fields of the eastern German state of Brandenburg, it spews 25 million tons of carbon dioxide into the air -- making it Germany's largest single emitter of the greenhouse gases, which are blamed for global warming.

As of Thursday, however, the technology of the last century exists side by side with that of a new era of energy production. Vattenfall Europe has begun testing a plant that will capture the CO2 emissions and pump them into deep rock.

Klaus Rauscher, a member of the board of the Swedish-owned company, says the technology is intended to make coal-fired power generation cleaner until alternative energy sources will be ready for commercial use.

"We are sitting on enough lignite here that will last us for the next 30 to 40 years," he said. "But it’s acceptable to use this resource only if we get a grip on the huge greenhouse gas emissions. Our pilot plant is capable of resolving this problem."

Burying the emissions

Vattenfall has spent 50 million euros ($67 million) on the new plant, which produces about 50 megawatts of electricity. The plant uses a technology called oxyfuel combustion which burns lignite in pure oxygen rather than air.

This produces only carbon dioxide and water vapour so that emissions can easily be liquified and pumped underground. It is said to be the most cost-effective method of capturing carbon dioxide.

"For us researchers it’s like entering uncharted territory with only our pioneering spirit to help us along," said Hans Joachim Krautz, who along with his research team at Cottbus Technical University in Brandenburg, developed the process.

Vattenfall has yet to find proper storage facilities for the captured CO2, but claims that this should not be a problem as exhausted natural gas deposits, for example, are well suited for that.

Long-term solution?

Critics of the technology say dumping greenhouse gases underground is not the long-term answer, and reducing emissions must take priority.

But even environmentalists say that there may be little other choice for the time being.

"We will continue to need fossil fuels for a while but have to make their use more climate friendly," said Manfred Fischdick, vice-president of the Wuppertal Climate Institute. "Carbon capture is one way of doing that."

If the trial runs at the Jänschwalde pilot plant turn out to be successful, Vattenfall plans to set up a bigger, 300 megawatt project by 2015. The first commercial CO2-emission-free lignite plant, the company says, is then likely to go into operation by 2020.