BIPV

Understanding BIPV (Built-In Photovoltaics)
By Jennifer Dooley
In an effort to reduce their carbon footprint and "go green," millions of people and companies have begun exploring or using Builti-In Photovoltaics-solar cells-as an alternative, renewable source of energy. The Earth's inhabitants use less energy in an entire year than the sun sends to the planet in 30 minutes. Development of solar technology is crucial because it will allow us to take advantage of a clean energy source that has no waste product. Increased presence of solar power could even provide electricity to the 2 billion people-approximately 1/3 of the population-who do not have it.
Below are several key facts about solar cells and solar energy:
-Charles Fritts built the world's first photovoltaic cell in 1883, when he coated a thin layer of gold over selenium; the resulting solar cell was barely 1% efficient.
-In 1946, Russell Ohl received a patent for the basic model of what we know as the modern solar cell
-Solar cells can currently be as much 28 to 45% efficient
-A typical solar cell is only .01 inches thick
-Currently, only 0.04% of the planet's energy usage comes from solar energy
-A solar cell works like this: sunlight makes contact with the cell, which releases electrons; the electrons form a DC (direct current), identical to the current flowing from a typical battery
-One watt of electricity is produced by a silicon cell of approximately four inches
-Solar cells are typically made out of silicon, though other light-absorbing materials that may be used for photovoltaic cells include Cadmium telluride and Copper-Indium Selenide
-Silicon comes from silica (or silica sand); it takes a great deal of energy to separate silicon from silica
-Over two years can elapse before a solar cell has converted enough energy from light energy to electricity to replace the energy that was used to make it
-A 2007 study sponsored by the National Science Foundation showed that when scientists placed nanoparticles of silicon over the pre-existing layer of silicon, the cells become more efficient and long-lasting
-Built-In Photovoltaics can serve as roof shingles, and carry the energy they convert directly to the building on which they reside
-Built-In Photovoltaics can also take the form of opaque glass facades
-Both types of building material can replace traditional building materials such as plastic, and so the money a company or family saves by installing BIPV comes not only from the free solar energy, but from not having to buy traditional materials
-Japan, Germany, China and the United States are the leading nations in the production of solar cell manufacturing
-Japan is the world's largest exporter of manufactured photovoltaics
-In 1985, consumer demand worldwide for solar panel installation was only 21 Megawatts
-The company Sharp is the world's foremost manufacturer of photovoltaic technology
-By 2006, this number had multiplied to over 3000 Megawatts
-In Germany, people who connect their BIPV systems to the public power system can earn almost 50 euro cents per kilowatt hour
-Each year between 1982 and 2007, consumer demand for solar energy increased 25%; in contrast, the demand for hydrocarbon energy has only grown annually at about 1%
Sources
"Fast Solar Energy Facts," SolarBuzz. Retrieved January 12, 2008, from
http://www.solarbuzz.com/FastFactsIndustry.htm
Kloeppel, James E. "Silicon Nanoparticles Enhance Performance of Solar Cells," Newsbureau: University of Illinois at Urbana-Champaign. Retrieved January 12, 2008, from http://www.news.uiuc.edu/news/07/0820solarcells.html .
"Solar Cell," Wikipedia: The Free Encyclopedia. Retrieved January 12, 2008, from http://en.wikipedia.org/wiki/Photovoltaic_effect#Current_research_on_materials_and_devices.
"Solar Electricity," Northeast Sustainable Energy Association, Retrieved January 12, 2008, from http://www.nesea.org/buildings/info/solarelectricity.html.