Hydropower is the world’s top source of renewable energy, producing a whopping 16 percent of the global energy supply. But hydropower is not without its environmental costs, particularly when it comes to the land that is drowned under reservoirs or gobbled up by roads and power lines built for a hydropower project. Now, a team of Norwegian-based researchers has developed an innovative way to describe how much land it takes to generate a kilowatt-hour of electricity from hydropower. The goal is to make it easier for policymakers and businesses to assess the environmental trade-offs of current hydropower plants and involved in investing in new hydropower plants.