The need to be able to store electricity as part of our low carbon future, has increased dramatically as the use of renewable energy has expanded. Both solar and wind energy rely on sunlight and weather, only providing intermittent power. Electric cars need to be able to travel greater distances on one charge and cost less to have mass market appeal. It’s clear batteries are a key - but evolving - technology. Improvements still need to be made to their safety, power and cost. Megawatt batteries are being built in many countries, in a step toward creating a renewable energy back-up for the grid. But these batteries are made using Lithium, which is limited because of their size, the length of their lifespan, and their track record in causing fires. We look at the limitations of the batteries that exist right now, and what new technology in the field is expected to bring in the coming 10 to 15 years. We also visit a hydro-pump powered energy storage system in Israel, where the company, Augwind, is developing an interesting alternative to electric batteries. Presenters Kate Lamble and Jordan Dunbar are joined by: Susan Babinec is Program Lead in Energy Storage at the Argonne National Laboratory Sandra Chavez is Director Partnerships at Powerhouse Gary Yang is Founder of UniEnergy Technologies Eshhar Chetsrony is the VP Business Development at Augwind Producer: Dearbhail Starr Reporter: Roni Dori Researchers: Lizzie Frisby Series Producer: Alex Lewis and Rosamund Jones Editor: Emma Rippon Sound Engineer: Andrew Garratt