Increased number of vehicles, consumer products and homes all require an increased amount of electricity. However the dwindling supplies of fossil fuels in the world today has made it necessary for scientist and researchers look for alternative sources of energy.
Solar energy is one source of renewable energy that is found aplenty in the environment and is harnessed for the supply of electricity.
However though solar energy is available for free, the installation of a solar energy system requires a sizeable investment, which makes it not feasible for everyone to use and depend on solar energy for their electricity needs.
This is why a group of scientists from UNSW are working on a breakthrough to boost the efficiency of solar cell technology where the price of an installed solar system for a house falls from about GBP 20,000 to GBP 15,000.
The main reason for the high cost in about 45% of the existing solar cell technology is attributed to the high cost of the silicon used in these cells to convert sunlight to electricity.
The reason silicon is used in the electronics industry is because it is stable and non-toxic. However though silicon has these advantages, it is basically a poor absorber of light.
So to reduce costs in its production, scientists are now using cheaper, thin film cells that have less silicon than the expensive thick silicon wafers that are usually used in solar cells.
However there is a disadvantage to these one to two micron thick films of solar cells where they have the capacity of converting only 8 to 10 percent of incoming sunlight into electricity. This is in comparison to the 25% efficiency of the thicker, but more expensive silicon wafers used in solar cells.
This is why scientists are looking at ways of boosting the efficiency of thin film technology, while keeping costs as low as possible.
There has been some success in this avenue with researchers at UNSW’s ART Photovoltaics Center of Excellence reporting a 16 fold enhancement in the light absorption of 1.25 micron thin film cells, for light having a wavelength of 1050nm. In addition to this, the scientists have reported a 7 fold enhancement in light absorption in the more expensive wafer type cells having light wavelengths of 1200nm.
At present, most thin film solar cells are between 8 to 10 % efficient. However with this new technique, it will be able to increase the efficiency of the solar cells to about 13 to 15%. This is a considerable improvement in solar cells as if these cells are below 10% efficient, it is not affordable to install them in your homes. This is because they take up too much of roof area to power the house.
In fact, once its efficiency approaches 15%, then it will be considered to be commercially viable to use it for homes. This is because an average home will have sufficient energy for its home with a solar system with panels covering 10 square meters. However this does not include the consumption of energy for cooking and hot water heating. With this new procedure and technique, more homes are expected to depend on solar energy for their energy needs in the near future.
