These two trends are linked more closely than one might think. China’s hunger is not so much for clean or dirty energy, as energy full stop. The country’s futuristic renewables sector is shackled to antiquated market structures that mean green and fossil power often go hand in hand. As a result, when President Xi Jinping encourages an acceleration down the road to the energy transition — as he did in a speech last week that boosted share prices for renewables businesses — it’s worth looking at the cloud of black smoke billowing out in its wake. A colossal renewable power...