At Yamakura Dam, 45 km southeast of Tokyo, construction workers are screwing together a 51,000-piece jigsaw puzzle of floating solar panels. When completed, it will be one of the world's largest floating solar projects.
Roughly 30 percent of the work on the project in Chiba Prefecture is complete, and when it comes online in 2018, the 13.7 megawatt facility will provide enough electricity to power almost 5,000 households annually.
However, even attention-grabbing projects like this one will produce less than 1 percent of what's needed for Japan to reach its 2015 goal of doubling its renewable energy use to between 22 and 24 percent by 2030 from around 10 percent at present.