Unless you have lived a very sheltered life, you have certainly seen solar electric panels on a rooftop or two, possibly in your own neighborhood. What are those steel-blue panels made of, anyway? You may know that the material involved is called a semiconductor, and that it is mostly made up of silicon. I did a little digging and found out that there is quite a bit more to know about these products that produce electricity from the sun.
Solar technology has come a long way since French scientist Alexandre Edmond Becquerel discovered that sunshine could be used to create electricity. Rudimentary photovoltaics used selenium as the semiconductor material until the 1950s, when researchers at Bell Laboratories found silicon to be a much better conductor of electricity. More research led to the discovery that "doping", or adding elements such as phosphorus and boron to the silicon, increased its conductive abilities to a much greater degree.
Types of Solar Electric Panels
There are several types of solar panels available today. Some have been around for many years, while others represent new, often more affordable, solar options.
Monocrystalline Solar Panels: These panels are made from slices of a single, cylindrical solar cell and are the most efficient, albeit pricey, solar panel option. In industrial applications, these panels are sometimes used with reflectors to maximize both their cost and energy-producing efficiency, estimated at 25%. The uniform appearance of these panels has a distinct appeal to some consumers.
Polycrystalline Solar Panels: Silicon is heated, then poured into molds or made into sheets which are sliced into squares. This method of panel production is much less labor intensive than that for monocrystalline panels, which is reflected in the price of the finished product. Despite the fact that these square cells leave no gaps in the panel's surface like the round monocrystalline style, they are less efficient, hovering around 15%. These are by far the most popular of solar electric panels, comprising more than 2/3 of the worldwide market according to the Union of Concerned Scientists.
Amorphous Silicon Panels: These panels are manufactured by spraying liquid silicon onto a rigid backing and is the least expensive method of making solar panels. With low cost comes reduced efficiency, however. Although manufacturers are constantly working to improve their product's power-producing efficiency, it is currently only about 5%.
Thin Film Solar Products
The newest technology available is thin film, flexible solar panels. Semiconductor material can be sprayed onto flexible backing materials, creating a product that can cover more surface area than rigid panels. Although their efficiencies are lower than rigid-frame panels, the fact that more surface area can be covered helps to boost the overall efficiency of the installation. In addition to amorphous silicon, other new materials are also being used for these products, such as copper indium gallium diselenide, or CIGS.
One of the most promising uses for CIGS is the solar roof shingle, like the Dow Chemical Powerhouse Solar Shingle. This product may very well revolutionize the solar industry for many reasons: production costs are lower and so are installation costs, since roofing contractors can install them; they can cover an entire roof and they have much more sidewalk appeal than a rooftop solar array.
Research and development in the solar industry is at a fever pitch, and solar power is becoming more and more accessible for the average consumer. Keeping abreast of the newest technology is the best way to understand how new materials promise to boost the solar panel's electricity-producing potential in the very near future.