The use of sunlight to synthesize useful chemicals such as H₂ and hydrocarbon fuels from components of air (water and CO₂) has progressed rapidly due to the strong international effort to identify materials and device architectures that improve efficiency and stability. The targets are challenging: a solar fuels generation system must return at least as much chemical energy as the total energy required to fabricate and operate it, and last for a decade or more. Success requires addressing corrosion, membranes properties, integrated semiconductor/catalyst systems and performance under natural conditions involving large temperature swings and diurnal operation. In this talk I will describe studies conducted in JCAP directed toward achieving these targets. Considerations for solar water splitting and CO₂ reduction systems will be compared.