Solar panel efficiency
Posted by Solar energy guru | Filed under Solar energy facts
One thing that people who scoff at solar power like to point out is that solar panel efficiency averages only 20%. What that means is that most photovoltaic (PV) panels convert only about 20% of the captured solar energy to electricity. Even the most advanced designs using silicon are only able to operate at around 40% efficiency.
When it comes to converting that energy to light, the efficiency actually ends up being dramatically lower. Let’s look at what happens if the solar panel efficiency starts at 20%. That energy starts as direct current which must be converted over to alternating current to be used in the home. This conversion process loses another 20% of the resulting energy. This alternating current now goes on to an incandescent lightbulb which is typically only 5% efficient. From all the original solar energy captured, you end up with only a fraction of usable energy.
Solar panel efficiency is obviously poor when it comes to lighting up our homes. Using the sunlight directly through daylighting techniques would use approximately 80% of the sunlight available - clearly much more efficient than first converting the solar energy into electricity. The most intelligent way to utilize solar energy is to make use of direct sunlight through daylighting and passive solar heating technologies and then using the highest efficiency solar panels for the rest of our energy needs.
Scientists who work on solar panel efficiency believe that the 40% level is the highest efficiency that can be achieved with the standard silicon materials in most solar cells. Instead of focusing on making them more efficient, the current focus is on how to manufacture PV panels less expensively. However, new technologies have recently been developed that may make solar panels that are much less expensive while achieving an incredible 80% efficiency.
Steve Novack of Idaho National Laboratories has come up with a unique way of creating a cheap, foldable solar panel that has so far topped all records for solar panel efficiency. This new technology utilizes nanotechnology by printing the material’s surface with tiny nano-antennae. These nano-antennae capture infrared radiation which is the part of the solar energy normally utilized with traditional photovoltaic panels but the nano-antennae are able to harness much more than the silicon solar cells.
The only problem with this new technology is that so far there isn’t any way to use the energy being captured. The scientists are now working on putting a mini-capacitor into each tiny antenna. That means that each separate antenna would have its own little AC/DC converter. They believe that they can do this while maintaining the solar panel efficiency and keeping the price of the panel inexpensive.
Another new technological development for improving solar panel efficiency has been developed by researchers at MIT. They have created what they call a solar concentrator using inexpensive dyed glass and some fiber optic technology. The concentrator is supposed to be placed over traditional solar panels and assist in capturing more of the wavelengths of visible light.
The dyed glass absorbs the sunlight and then guides the energy generated to the edges of the glass sheet. Eventually researchers hope to replace the expensive silicon cells with the special sheets of glass that direct the energy similar to the way fiber optic technology does. This would allow for smaller amounts of silicon to be needed for generating the usable energy.
As scientists continue to work on increasing solar panel efficiency, the cost of switching to solar power will keep coming down. Although solar energy currently costs more than other types of energy to produce, new developments continue to bring prices down. Soon home solar power will be as cost effective as other forms of energy.
October 14th, 2008 at 8:31 am
I am very tired of companies promoting products that are years out in development or have yet to be close to providing any form of economical mass production. All this is doing to the uneducated average American is keeping them on the hook for another number of years WAITING for something that may or may not happen. It is good for venture capital envestors but not good for the american economy or our use of foreign oil. Although they are not perfect we need to stop hiping and start installing solar panels on every house in America,,, just like the Germans are doing.