Hydrogen could help store renewable energy and power fuel cells, but storing it remains difficult because hydrogen gas has a low density under everyday conditions. Compressing it to high pressure or cooling it into a liquid requires substantial energy and specialized equipment. Solid materials that absorb or adsorb hydrogen offer an alternative, but finding materials that store enough hydrogen, release it under useful conditions, work quickly and survive repeated use remains a complex challenge.Hydrogen could help store renewable energy and power fuel cells, but storing it remains difficult because hydrogen gas has a low density under everyday conditions. Compressing it to high pressure or cooling it into a liquid requires substantial energy and specialized equipment. Solid materials that absorb or adsorb hydrogen offer an alternative, but finding materials that store enough hydrogen, release it under useful conditions, work quickly and survive repeated use remains a complex challenge.Energy & Green Tech[#item_full_content]