An Integrated, Systems Approach to the Development of Solar Fuel Generators

40% of current global transportation fuel is consumed in uses for which electrification is technically difficult, if not impossible, such as in heavy-duty trucks, ships, and aircraft.2 Exhaustive use of advanced biofuels might possibly supply adequate carbon-neutral transportation fuel for these uses, but could not then also fulfill the requirement for long term, massive, grid-scale energy storage.3 Chemical fuels are desirable for energy storage because fuels are the most energy-dense storage medium known to man (other than the atomic nucleus), and could simultaneously provide a means to baseload at scale intermittent renewable energy resources while also fulfilling gaps in the need for high energy-density, carbon neutral, sustainable, transportation fuels.4 Hence a clear rationale exists to