With the exhaustion of fossil fuels, new sources of energy are being used to generate electricity, and solar energy is one of them. The solar power system stores solar energy in solar cells and then converts it into electricity. It is one of the most reliable and long-lasting sources of energy with the added advantage of being sustainable. However, the lack of large-scale energy storage system is a big problem for solar power systems due to which there is still dependence on the electric power grid.
The solar power system is one of the most reliable and long-lasting sources of energy.
A team of researchers—including Rachael C. Huber, Amy S. Ferreir, Robert Thompson, Daniel Kilbride, Nicholas S Knutson, Lekshmi Sudha Devi, Daniel B. Toso, J. Reddy Challa, Z. Hong Zhou, Yves Rubin, Benjamin J. Schwartz, and Sarah H. Tolbert—at the University of California, Los Angeles (UCLA), has discovered a new process for designing solar cells which are capable of storing energy for a longer period. This technique of taking ideas for new processes from biology is known as ‘Biomimicry’ which includes production of materials based on biological processes or simply, the imitation of nature.
Made up of plastic, the solar cells mimic the mechanism of photosynthesis which is used by plants to produce energy using sunlight.
The materials used for this cell include polyelectrolytes: polyfluorene-alt-thiophene (PFT) and a fullerene derivative which is a water-soluble semi-conducting polyelectrolyte.
There are two basic elements, a polymer donor and fullerene acceptor. PFT is the polymer donor which upon photoinduction releases electrons. Electricity is generated by the fullerene acceptor upon accepting electrons from the polymer donor.
Upon photoexcitation, separate charges are created by photosynthetic complexes during photosynthesis. When light is absorbed by the chlorophyll molecules, the energy of electrons increases and they go in excitation state which then causes the breakdown of water molecule, thus generating protons, electrons, and oxygen. This is then used to produce chemical energy.
Photovoltaic cells mimic the same process, as when they are hit by light, the energy is transferred to the semiconductors present inside which in turn force the electron to be released. These electrons are now able to flow freely throughout the cell and this flow of electrons generates current which can be drawn and used as electricity.
So, by mimicking the biological process of photosynthesis, long-lived polarons (stable pair of separated charges) are produced that are stable for weeks and store energy for a longer period of time.
This is one way ‘Biomimicry’ can inspire breakthroughs in the solar energy sector and possibly revolutionize the field of renewable energy.