High efficiency solar cells
Posted by Solar energy guru | Filed under Solar panels & photovoltaic cells
New solar technologies are replacing conventional silicone solar cells with new high efficiency solar cells. Innovative new photovoltaic designs like dye sensitized solar cells, thin film cells and triple junction cells are being produced. It is hoped that by the year 2020 the cost of this source of renewable power will be competitive with fossil fuels.
After the first silicone solar cells were developed, a second group was developed that were considered to be high efficiency solar cells at the time. These were made out of very thin semiconductor deposits and are called silicon water-based solar cells. These were high efficiency solar cells when compared with the older type of silicone glass solar cells, but they are not as highly efficient as newer types. They use cheaper material and are popular with consumers who look for efficiency in performance in their solar panel systems. They significantly reduce the amount of space that solar cells take up and these high efficiency solar cells are suitable for placing on the roofs of homes.
Another development in high efficiency solar cells is radically different than the previous two types. These are even more advanced high efficiency solar cells. The newer type does not use semiconductors but are classed as “Triple Junction” high efficiency solar cells. Innovative and technologically advanced, these solar cells were developed by Spectrolab and are being marketed by them. Triple Junction high efficiency solar cells have efficiency ratings at 26.8% and the technology for them was inspired by Mars Rover solar cell design. They are made by a germanium wafer that is spun in an isolated vacuum at a very high speed. The wafer is then differentiated into a seminconducting material that is actually 20-30 thin sheets that are made from the wafer.
Before the Triple Junction high efficiency solar cells were developed, conventional solar cells were one single-junction silicon cells. They use the light that our sun produces naturally. Spectrolab’s “Three Junction” solar sells use the equivalent of 100s of our sun instead of just one because it uses a concentration of mirrors and lenses to produce magnified amounts of sunlight. These are much more highly efficient than using broad range sunlight wavelengths. Dr. Richard R. King, a principal investigator of a high efficiency solar cell research and development effort, has stated that “The excellent performance of these materials hints at still higher efficiency in future solar cells.”
As far as electrical energy output goes, conventional solar cells are rated as being very efficient in how much electrical output per energy incident they can produce. However, by industry standards, a high efficiency solar cell is one that can be the most cost efficient rather than the most energy efficient solar cells.
Nanotechnology has now entered the arena of high efficiency solar cells. The Wake Forest Center for Nanotechnology and Molecular Materials has created high efficiency solar cells and a new kind of nanoscale polymer “tree”. It is made of micro fiber-optic wires that are able to absorb the incoming sunlight and channel electrons to a photovaotaic film.
Just recently, the U.S. Department of Energy’s National Renewable Energy Laboratory was awarded a prize for its Inverted Metamorphic Multi-junction, IMM. This High Efficiency Solar Cell and was named a winner of the 2009 Award for Excellence in Technology Transfer by the Federal Laboratory Consortium for Technology Transfer.
The Inverted Metamorphic Multijunction, IMM, has layers of multiple thin films that can capture a broader ranger of the solar spectrum to convert into electricity. This solar cell has a solar efficiency record of 40.8 percent under 326 suns worth of concentrations. This record was later replaced by The Fraunhofer Institute for Solar Energy systems solar cell when they achieved a 41.4 percent efficiency rating. Development in solar cell technology is moving so fast that forecasts are constantly changing.