Creating Liquid Fuel from Sunlight: Hydrogen Energy: Eco20/20

Creating Liquid Fuel from Sunlight

Using sunlight to create energy is an easy task if the location that needs the energy is stationary, like a building. But creating energy from sunlight to power things like cars has been a challenge. And those technologies that are tackling the problem have hurdles of their own, like the weight of batteries needed to power an electric vehicle. However, new research advances will make it possible to create a liquid fuel from sunlight in a highly efficient way.

Currently, the most common way to produce liquid fuels from sunlight is through biofuels, such as when sunlight is used to grow corn which in turn is used to create ethanol. The current production method is very inefficient though, with less than one percent of the sunlight energy actually being converted into fuel. This is highly inefficient and not likely to improve without significant scientific breakthroughs. This is changing though.

Researchers at the California Institute of Technology, Caltech, are working to create hydrogen and carbon dioxide which can be used to artificially make hydrocarbon fuels for vehicles. The process begins with cerium, a relatively common metal. Cerium oxide and water are placed in a reaction chamber. The chamber is heated with sunlight focused using a regular parabolic mirror. The water breaks apart into carbon dioxide and hydrogen and the process does not use up the cerium so it can be used again. The hydrogen and carbon dioxide are then used to create hydrocarbon fuels.

In terms of sunlight energy efficiency, this new process is about the same as ethanol - less than one percent of the sunlight energy is converted into fuel. Despite that low number, researchers did calculate that the process could become much more efficient though. The researchers calculated that with larger and more advanced systems, their new cerium process could return about ten percent of the sunlight energy.

Many researchers are also working to create liquid fuels from sunlight through trying to replicate photosynthesis. Leaves basically harvest light and turn it into liquid energy. Researchers hope to do the same thing. Researchers hope to create liquid fuel energy sources that are carbon-neutral as well as renewable. In essence, these researchers are trying to create an artificial leaf which does the same job as a real one.

Despite all the hype, this cerium process is intended to replace fossil fuels as an energy source, not specifically to create green energy. In fact, when the water breaks apart and is used to create petroleum-like fuels, it releases carbon dioxide into the environment. This means that the process itself does have a carbon footprint, even if the components used do not. However, like all green energy projects there is still a significant hurdle of investment and research dollars to really find out what these advancements might accomplish.