One of the challenges of clean energy like wind or solar is that they fluctuate. And they're unreliable. So finding a better way to store this energy for dark seasons and doldrum days is the next hurdle to reaching goals for decarbonization. In this episode, we explore options that are already being used, and some new methods still in beta. WSJ Senior Energy Correspondent Sarah McFarlane joins host Janet Babin.Learn more about your ad choices. Visit megaphone.fm/adchoices