2012 was a banner year for renewable energy that saw scientists and engineers pushing the envelope towards ever more efficient and sustainable ways of producing power. Entire nations reaped the benefits of photovoltaics during record production periods while upstart innovators brought alternative energy into our own backyards. From ultra-efficient bird-friendly wind turbines and pop-up DIY photovoltaic factories to spherical solar cells that harvest light from every direction, read on for our top renewable energy stories of 2012 – and make sure to vote for your favorite!