Reasons for the decline include:
- Low natural gas prices make it more difficult for renewable energy projects to compete
- Capital intensive deals are out of favor with venture capitalists, after failures like MiaSole.
- Global economic uncertainty also took a toll
Here's a link to the article:
http://www.mercurynews.com/business/ci_22305241/cleantech-cliff-global-venture-capital-investment-plunged-33