It would be optimal if clean energy investment increased every single year, but that's probably not totally realistic. Some years, there are economic problems, policy issues, and other factors that can interfere with the long-term upward trend. One of those years was 2012. Still, in spite of significant "headwinds," the overall results weren't too shabby last year.
[Bloomberg New Energy Finance] reported Monday that overall [clean energy] investment was $269 billion [in 2012], down from $302 billion in 2011 but still the second highest level ever, according to its database.
“We warned at the start of last year that investment in 2012 was likely to fall below 2011 levels, but rumors of the death of clean energy investment have been greatly exaggerated,” Michael Liebreich, the company’s CEO, said.
“Indeed, the most striking aspect of these figures is that the decline was not bigger, given the fierce headwinds the clean-energy sector faced in 2012 as a result of policy uncertainty, the ongoing European fiscal crisis and continuing sharp falls in technology costs,” he said.
In sum, 2012 wasn't an ideal year in many ways for the clean energy investment, yet it was still quite robust. That bodes well for 2013 and beyond.