Humanity is in the midst of an energy revolution. To save our climate, we must phase out fossil fuels. But wind and solar power aren't always available. This science documentary explores the exciting race to develop new energy storage technologies that could bring stability to green energies. The film takes us behind the scenes of research facilities and start-ups that are shaping the future of energy storage. From batteries to hydrogen, from traditional hydroelectric dams to supercapacitors and cutting edge flywheels made from carbon fiber - join this thrilling journey into one of the most important areas of research today.