China's historic move away from coal shows why investors need to keep digging

China reached a significant milestone a few weeks ago. To quote a triumphant announcement by the National Energy Administration (NEA): "The historical pattern of coal power serving as the largest power source has been broken."  Yes, after more than a century of dependence on fossil fuels, solar energy is now dominant in the world's second-biggest economy. At the end of July it accounted for 1,286 gigawatts of China's overall power generation – equivalent to 31.5% – compared with coal's 1,285 gigawatts. The margin might have been narrow, but this was still major news – or at least it w...