Carbon-free technologies like renewable energy help combat climate change, but many of them have not reached their full potential. Consider wind power: over the past decade, wind farms have become an important source of carbon-free electricity as the cost of turbines has plummeted and adoption has surged. However, the variable nature of wind itself makes it an unpredictable energy source--less useful than one that can reliably deliver power at a set time. In search of a solution to this problem, last year DeepMind and Google started applying machine learning algorithms to 700 megawatts of wind power capacity in the central United States. These wind farms--part of Google's global fleet of renewable energy projects--collectively generate as much electricity as is needed by a medium-sized city.