My only reason to believe that is not what is happening is that China, and the Chinese, are too smart to using coal as a peaking or emergency source of power. The only thing worse than coal for peaking is nuclear. Oil, Gas, and hydro are all much better for short-to-mid term peaking and batteries - something they're very good at and have vast resources for - are perfect for short term emergency/failover loads. I believe (without documentation) that they are building extra capacity for the possibility of another expansion - the incubation of so many "third world" economies and partnerships across Asia and Africa to spur demand for their domestic production. If they don't use it, it was a jobs program; if they find they need it, they will accept short term cash and economic power for a worsening of the world environment. In a way, the largest communist country on earth is also the largest capitalist power. Ironic.