Europe's clean tech TOP 100 companies, solar cell maker Oderson....

The hi-tech firm that provided solar cells for the roofs of the buildings in Beijing's Olympic Park has been named as Europe's hottest clean technology company, according to a team of business analysts and venture capitalists.

German company Odersun makes cheap thin-film solar cells that do not use silicon and was voted top of the inaugural Guardian/Library House CleanTech 100. Others in the top 10 include DeepStream Technologies, a Welsh company that builds circuits to help buildings monitor and cut their use of energy, two British marine power companies, and, reflecting the expected rise in the technology, three further solar cell manufacturers.

The CleanTech 100 was an "exciting glimpse into the future", said Richard White, senior analyst at Library House. "The aim is to highlight the most promising private companies focused on clean technology, selected on the basis of their potential for future growth and beneficial impact on the environment.

"With climate change and energy use nudging to the top of political and commercial agendas, these are companies that have a stake in how our world develops."

Clean, or green, technology is loosely defined as anything that helps consumers or industries to use raw materials such as energy and water more efficiently and, in the process, improve their environmental footprint.

Thanks to an increased global awareness of climate change and the rising cost of fossil fuels, the clean technology sector is poised for a boom: according to Library House, venture capital investment in European cleantech companies went from £407m in 2006 to £805m in 2007. Globally, the figures went from around $850m in 2004 to $6bn in 2007.

It is also an important industry politically, given that the UK government has committed to source 15% of its primary energy from renewable sources by 2020, which equates to around 40% of the country's electricity.