U.S. Energy Secretary Steven Chu said yesterday that he supports investments to develop technology that captures and stores carbon emissions originated from burning coal, but added that it would take a minimum of eight years to develop a cost-effective technology.

As part of President Barack Obama's administration, Chu supports a renewable energy plan which aims to save energy, reduce oil dependence and protect the environment. However on Tuesday, Chu admitted he was doubtful if the U.S. would turn its back on coal, one of the most powerful emitters of carbon dioxide.

Even if the United States or Europe turns its back on coal, India and China will not...quite frankly I doubt if the United States will turn its back on coal. We are generating over 50% of our electrical energy from coal, Secretary Chu told reporters according to the Wall Street Journal, after a conference with the Energy Information Administration.

Clean-coal technologies trap carbon dioxide before it can be released. In some cases the CO2 can be turned into liquid and kept in wells underground.

Mr. Chu, a Nobel Prize Physics winner in 1997, also commented about the use of natural gas as fuel for transportation, proposed by T. Boone Pickens. Chu said this would put a strain on natural gas for industrial uses and leaned for the creation of fuel-efficient cars and biofuels, the paper noted.