As one of the most abundant and widespread energy resources available, sunlight is very attractive as a renewable energy source that could be the pillar of a sustainable energy future. In the last several decades, decreasing costs of photovoltaic technology have helped spur the spread of solar electricity. However, at present solar energy remains a minor player in the global energy landscape. Even as the evolution in photovoltaics manufacturing continues to reduce the cost of solar electricity towards a level that is economically competitive with fossil fuels, the widespread implementation of solar as a primary energy source will require the ability to overcome the intermittency of sunlight.
In order to have energy from the sun at night, a cost-effective storage mechanism is needed. Battery systems are generally too expensive for large scale deployment, and mechanical storage methods, such as pumping water uphill, require enormous reservoirs in favorable locations. An ideal solution would be to store solar energy in the form of chemical bonds – to convert sunlight into energy-dense fuels. Nature utilizes this approach through the mechanism of photosynthesis. However, the energy conversion and storage efficiency of even the most rapidly growing plant is less than 1%. By pursuing artificial photosynthesis, the combination of light absorbing semiconductors and highly active catalysts in an inorganic photoelectrolysis system, cost-effective fuel production at higher efficiency is possible.
The Conn Center is striving to develop new and promising approaches in the field of solar fuels. This effort includes the study of novel photoactive semiconductors and surface preparations to make efficient photoelectrodes for fully integrated solar water-splitting systems. New synthesis approaches to make earth-abundant and highly active electrocatalysts for water-splitting are being explored. The center is also researching the design of electrolyzers to reduce carbon dioxide into useful hydrocarbon fuels efficiently and with high yield. Another carbon-free liquid fuel is being pursued by studying plasma-assisted electrolysis of nitrogen and water to liquid ammonia. Each of these research thrusts is dedicated to energy-dense clean fuel synthesis and lowering the ultimate cost of solar fuels production.