Within two generations humanity is set to leave behind the fossil fuels which built our modern industrial civilisation. The clean energy transition is already underway, and its completion inevitable. So what lies ahead in our future? The key technologies of wind, solar, pumped hydro, batteries, heat pumps and green hydrogen are going to be key, argues Black. But transitions are not necessarily going to be smooth: fossil fuel corporations will go bankrupt and workers will lose jobs; the most powerful fossil fuel states have always pushed back and will continue to do so as their market contracts. However, water cannot be pushed uphill for any length of time. Already clean energy costs have fallen so far that almost all electricity generation capacity being built around the world is renewable; soon, for example, electric models will account for almost all growth in the global car fleet. As more are built, costs come down and rollout accelerates. Whether the transition happens fast enough to keep climate change within limits commonly regarded as 'safe' is another matter. But, argues Black, the future of energy is postive, with clean energy helping to preserve and enhance living standards, slow climate change, boost democratic values and reduce costs. A revolution is coming.