The company also applied its technology to generate electricity from geothermal sources.

The breakdown by source in 2003 had been: 59% from conventional thermal sources, 35.4% from hydroelectricity, 7% from nuclear power and 1% from geothermal sources.

Some subsurface water associated with geothermal sources contain high concentrations of toxic elements such as boron, lead, and arsenic.

Others such as carbon dioxide and methane are important greenhouse gases and are produced anthropogenically but mainly by plants, microorganisms and from natural geothermal sources.

This conclusion has regard to the fact that geothermal sources have to be developed sustainably because they can cool out if overused.