Molten salt and human sweat: the weird batteries that could store renewable energy

From Nevada to Manchester, developers are trialling innovative solutions to clean energy’s biggest challenge In the deserts of the United Arab Emirates a sprawling clean energy project, stretching across an area roughly the size of 12,600 football fields, will play host to a breakthrough allowing solar energy to power the equivalent of half a million homes through the night. The Gulf state has been steadily combining 5.2GW of solar power capacity with 19GWh of battery storage to create the largest battery scheme in the world. Meanwhile, about 7,500 miles away, at the US’s National Renewable Energy Laboratory facility in Colorado, researchers and engineers are making some of the smallest batteries the world has ever seen. A fraction of the size of the grid-scale lithium-ion batteries used to store renewable energy, they have been designed to power electronic tags that will track the 3in-long (about 7.5cm) young from salmon and eel species. As traditional lithium-ion batteries push boundaries in size and scale, alternative battery types could provide the same vital role in harnessing low-carbon energy – but without the scramble for critical minerals such as lithium, cobalt and nickel