Energy materials: What strategies did nature pursue?

Nature looks back at a long evolution of successful energy materials, which have especially been adapted to deal with small energy quantities from the environment. Few basic organic materials, such as cellulose, chitin and keratin have been selected and highly diversified, mostly via nano‐and micro‐technological modifications. A similar strategy occurred with inorganic compounds, such as silica, hydroxyapatite, or calcium carbonate. Others were precisely tailored to support well‐defined strategies such as, for example, the kinetic solar cell principle, ionic energy converters, water splitting, quantum light collection, encapsulation, or fire resistance. In an attempt to learn from nature relevant aspects of biological energy conversion, relevant materials are analyzed and discussed. By looking at them we can more critically judge present technical–industrial developments and recognize unexploited energy and material technologies. This is a tree‐fungus of unidentified name growing on hazelnut. With chitin in its cell walls, it is a marvel in enzyme mediated energy catalysis for converting and upgrading of polysaccharides including cellulose. Its astonishing surface structure is reflecting self‐organization with fractal, self‐similar patterns.