ABSTRACT: The artificial leaf accomplishes the energy storage process of photosynthesis and does so with: Earth-abundant materials, No wires, Direct solar-to fuels process. Two earth abundant catalysts have been discovered that promote the oxygen evolving reaction (OER) and hydrogen evolving reaction (HER). The ability to operate these catalysts under benign conditions (in water at pH 7 and under 1 atm) has enabled the construction of the artificial leaf, which consists of a silicon wafer, coated with the respective OER and HER catalysts. By immersing the artificial leaf in water and holding it up to sunlight causes efficient water splitting; and all of this is done with no wires or membrane. By constructing a simple, stand-alone device composed of earth-abundant materials, the artificial leaf provides a means for an inexpensive and distributed direct solar-to-fuels conversion process with low-cost systems engineering and manufacturing requirements. The science behind the catalysts and the artificial leaf will be presented.