In a factory in a smoggy corner of China’s inland Shaanxi province, the country’s world-leading solar industry is on display. Robots scoot around carrying square slices of polysilicon, a crystalline substance usually made from quartz. The slices, each 180mm across and a hair’s breadth thick, are called wafers. They are bathed in chemicals, shot with lasers and etched with silver. All that turns them into solar cells, which convert sunlight into electricity. Several dozen of these cells are then bundled together into a solar module. The factory, owned by LONGi Green Energy Technology, can churn out about 16m cells a day.
