Zhang was the founding father of the captive coal plant model, or `Weiqiao model', in which the company powers its own production plants with its own coal plants. Before transforming the aluminium industry, Zhang became known as the `textile king' when he plugged a coal plant into one of his textile factories in 1999. It's now widely used across Chinese industry but it's concentrated in the highly energy-intensive primary aluminium production, where owning a coal plant is a competitive advantage because it avoids costly electricity bills. With cheaper energy, his textile company grew into one of the largest denim and cotton-yarn businesses, and the company's aluminium segment competed against Chinese state-owned enterprises and other international giants. Zhang became the `aluminium king'. Other Chinese aluminium firms copied his model, especially in Shandong province, and also thrived. But Zhang built his own electricity grid. Hongqiao always seemed to be a step ahead.