BBC: US energy group First Solar has signed a preliminary deal to build the world’s biggest solar power plant in China. The 10-year project would result in a two gigawatt plant – enough to power three million Chinese homes – at Ordos City in Inner Mongolia. First Solar will begin constructing a 30 megawatt demonstration project in June next year. China is expanding its use of solar power as it works towards meeting ambitious renewable energy targets. First Solar has …