A decade ago, clean-energy companies were the hot trend that venture capitalists were chasing. Oil and natural-gas prices were on the rise and Al Gore’s “An Inconvenient Truth” had just made its premiere.
But high hopes that the clean-energy sector would replicate the big returns of biomedical and software startups quickly faded. Instead, monumental losses piled up: Venture-capital investors lost more than half of the $25 billion they pumped into clean-energy technology startups from 2006 to 2011.
