According to the Cleantech Venture Network, investments into green technology in the form of North American venture capital has jumped 35 percent last year to more than $1.6 billion.

Cleantech investments by venture capital firms rose to a record $502 million during the fourth quarter of 2005 — 18 percent more than the previous quarter and 60 percent more than the same period a year earlier.

"We saw consistent upward growth in the amount of investment, the number of investors and the range of things invested in," said Nicholas Parker, chairman and co-founder of the Ann Arbor, Mich.-based Cleantech Capital Group.

Cleantech companies and technolgoy include those related to water purification, air quality nanotechnology, alternative fuels, manufacturing, recycling and renewable energy such as solar, wind and hydrogen.

In the last quarter of 2005, cleantech companies utilized 10% of the venture capital available, pushing it to fifth on the list behind biotechnology,software, medical technology and telecommunications, the report said.

The report attributes thie interest in cleantech companies to the rising cost of oil as well as other natural resources.

"Being much more efficient with natural resources is now an economic imperative," Parker said. "The rise of China and India and other emerging market economies is forcing up prices of natural resources of all kinds."