Quick Start — The Rise of Solar Power

Two decades ago, generating electricity from sunlight was a niche pursuit, championed by environmentalists and a handful of governments willing to subsidise an expensive technology. Today, solar power is the cheapest source of new electricity in most parts of the world. The shift has been driven less by political will than by a long, steady decline in the cost of solar panels — a fall of more than 90 percent since 2010. Several factors lie behind that drop. Manufacturing has moved to enormous Asian factories, where economies of scale push the price per panel ever lower. Engineers have steadily improved the efficiency of the silicon cells inside each panel, so a panel of the same size now generates roughly twice as much electricity as one made in 2010. Meanwhile, batteries — once the weak link in any renewable system — have followed a similar curve, allowing solar farms to supply electricity even after sunset. None of this means coal and gas will vanish overnight. Existing power stations represent decades of sunk investment, and the grids that distribute electricity were not designed for fluctuating renewable supply. Yet the economics increasingly favour solar. In country after country, new solar farms are now being built without subsidies — something almost no analyst expected only ten years ago.