Renewable energies for the energy transition: examples of artificial leaves for the conversion of sunlight into chemical energy

There’s a tiny little engine in the green of this grass and in the green of the trees that has the mysterious gift of being able to take energy from the rays of the sun and store it up. You see that that’s how the heat and power in coal and oil and wood is stored up. Well, we thought if we could find the secret of all those millions of little engines in this green stuff, we could, we could make big ones! And then we could take all the power we could ever need, right from the sun’s rays. (G.S. Kaufman; M. Hart 1936)