Scientists have created a way that solar energy harnessed in the day can be used at night. Solar energy is much cleaner and more sustainable than fossil fuels; however, its collection poses a problem – it can only be harnessed when the sun is in view. Researchers believe they have found a solution. Instead of being dependent on direct solar energy, solar energy can be used to create hydrogen energy that can be stored.
Currently, the harnessing and production of solar energy is a very expensive process and requires vast stretches of land filled with photovoltaic panels. The time for return on investment from solar farms can sometimes exceed decades. Compared to oil and natural gas, solar power yields very little. With a new way of thinking, researchers have found a novel way to utilize the power of the sun for our benefit.
Researchers at The University of North Carolina at Chapel Hill (UNC) have taken their advice from plants. They have found a way to convert ordinary sunlight into hydrogen rather than electricity. Chemistry Professor, Tom Meyer, has headed the project at the UNC Energy Frontier Research Center to create an artificial system of photosynthesis. By doing so, they have proved to all that solar energy can now be used at night. He stated, “The key to it is that it represents this most recent observation we made – a breakthrough.”
The process of converting sunlight into hydrogen uses a device called a “dye-sensitized photoelectrosynthesis cell” – DSPEC for short. The hydrogen is created by DSPEC using the sun’s energy to divide water atoms into hydrogen and oxygen. After the molecule is fractured the hydrogen is able to be stored and the oxygen is left over – basically the opposite of harmful byproducts of fossil fuels.
Meyer’s application uses two very small components in the energy assembly – a molecule and a nanoparticle. Meyer’s application uses a chromophore-catalyst to collect sunlight which is used to separate the electron from the water. The nanoparticle is then used as a film that transports the electrons away from the assembly to produce hydrogen fuel.
At first, the researchers at UNC had problems with the collection and separating of the molecules into their respective atoms. One main problem was that electrons could not be harnessed and collected at a quick enough pace to create hydrogen. Meyer’s research team partnered with another group at North Carolina State University under the supervision of Greg Parsons to attempt a collaborative effort to solve such a “small” problem. Parson’s group used an application wherein the nanoparticle was matched with an atomic veneer of titanium dioxide. Using this method, the atomic coating allowed the team to successfully transport electrons at a quick enough rate to create hydrogen. With a similar device, they were also able to create a way in which a coating could be developed for the chromophore-catalyst assembly to be tethered together with the nanoparticle to allow its optimization.
This new form of energy development solves the age-old problem of the sun going down at the day’s end and limiting solar collection. It also allows for effective fuel generation without the release of greenhouse gases into the atmosphere. Meyer stated that this energy is not even stored in any type of storage cell. “It turns out that the most energy-dense way to store energy is in the chemical bonds of molecules,” he said.
Meyer’s team has proven that solar energy can be used at night. It may take years to refine the application and test it on a larger scale before he is ready to develop the technology for real world application. However, the knowledge that the odds have been defied in the race to create a sustainable form of energy and combat the onset of fossil fuel pollution now exists.
By: Alex Lemieux