Japan's renewable energy puzzle: solar push threatens environment

As the country rushes to cut carbon emissions by 26%, campaigners worry that forests and wildlife are being trampled

The tens of thousands of solar panels resting on the surface of the Yamakura dam reservoir have finally begun to earn their keep.

This floating solar farm in Chiba prefecture is the biggest of its kind in Japan - and one of the largest in the world - covering 180,000 square metres, or roughly equivalent to 25 Wembley stadium pitches.