Molten salt, sweat-based and other novel batteries could unlock large-scale renewable energy storage

Developers worldwide are trialling alternative battery technologies — including those based on molten salt and biological fluids — as solutions to renewable energy's biggest challenge: storing power when the sun is not shining and the wind is not blowing. The United Arab Emirates has combined 5.2GW of solar capacity with 19GWh of battery storage to create the world's largest battery scheme, capable of powering the equivalent of half a million homes through the night. Unlike conventional lithium-ion batteries, many emerging technologies avoid scarce critical minerals such as lithium, cobalt and nickel, can sustain indefinite charge-discharge cycles, and are designed to be recycled at the end of a typical 20-year service life.