Direct Conversion of Solar Energy into Fuel

The concept of transforming solar energy directly into fuel is not easy. The method was tried out by researchers for the past decade and many prototypes were developed. But all the past attempts had some basic problems like life span, cost and efficiency and even the combination of all three. Some ideas remained intact as the materials required to conduct the experiment was very costly and were also not abundant. As the basic idea was to commercialize it, there was no point in conducting costly experiments and getting a positive result. Due to the failed attempts the Basic Energy Sciences Advisory Committee even declared this process as an “unsuccessful breakthrough concept”.

A chemist from Massachusetts institute of Technology (MIT) called Daniel Nocera was able to develop a solar powered device that could break water into its two basic components – hydrogen and oxygen. The device is no bigger than a playing card and is made from very cheap materials.

This prototype can be called the “Artificial Leaf” as it represents the same process of tree leaves which convert the sunlight into energy.

This artificial leaf consists of a combination of a solar cell and the device that is needed to conduct electrolysis. They are joined together as one piece and the solar cell is chemically painted with a catalyst and then immersed in water. The main use of the catalyst is to drive the main fuel producing reactions such as the reduction of CO₂ and oxidation of water. The prototype was only developed in order to mimic the conventional photosynthesis method that the tree leaves carry out.

When the energy that the fuel can store and its density is compared with the energy that is stored in batteries, it is way higher. This was one of the basic reasons for conducting such an experiment. Due to the success of this method, the future developments will be carried out by the Joint Center for Artificial Photosynthesis, which was formed mainly for this purpose. This project will be developed together by Lewis’ California Institute of Technology and DOE’s Lawrence Berkeley National Laboratory. For the purpose many researchers from two government labs and six universities have already been appointed.

As a development in the process, the main aim of these researchers will be to design a commercially successful solar energy to chemical fuel conversion system with high efficiency and life span. For the experiment, strong and photochemically stable light absorbers will be needed along with highly efficient catalysts.