Solar energy needs innovation to realize its potential

Solar energy, once a niche application for a limited market, has become the cheapest and fastest-growing power source on earth. What's more, its potential is nearly limitless-every hour the sun beams down more energy than the world uses in a year. Recognizing this, Prime Minister Narendra Modi has set an audacious target to build 100 gigawatts (GW) of solar capacity to power India's growing economy, expand energy access, and limit India's contribution to climate change. But in my new book, Taming the Sun , I argue that the world is not yet equipped to harness the full potential of sunshine, and India in particular is headed for trouble. Solar only generates 2 per cent of global electricity, and must surmount formidable barriers before substantially displacing fossil fuels. Those barriers-from a shortage of investment to stagnant solar technology to the unpreparedness of power grids to handle large amounts of volatile renewable power could cause solar's heady surge to flame out, halting a clean-energy transition.