The clean renewable economy needs hydrogen to store energy. Electricity generated from photovoltaic panels during the day, for example, needs to be stored so that it can be used during the evening and night when the sun doesn’t shine and the panels don’t produce energy. So far the best way to produce hydrogen is through the electrolysis of water. This process requires expensive and rare metals. Scientists in Japan have been looking at how nature splits water and they have discovered how water can be split using manganese in the same way as nature does that. This discovery is a major contribution to the use of water as a resource for generating renewable energy, which is a vital foundation for sustainable human societies.