James Macnaghten

Around the world, factories making food, drink, pharmaceuticals and other everyday products rely on steam, often produced by fossil-fuel boilers. James Macnaghten, founder and CEO of Caldera, is betting that thermal batteries can provide a cheaper and more flexible alternative that stores electricity as heat, and delivers steam on demand. This week on Cleaning Up, Bryony Worthington visits Caldera's factory to see how it makes its heat batteries: combining recycled aluminium and iron ore pell...