Photovoltaic Solar CellsSolar energy is a general term for any process that converts sunlight into energy. Two common forms of solar energy are used today: photovoltaic solar cells and solar thermal technology. Solar thermal technology uses heat generated by sunlight to create energy. Most commonly, this can be used to heat water in a home or other projects. Or, with increasing complexity, it can turn heat into electricity. Unfortunately, much of this technology is too expensive and complex to be widely applicable in the United States. However, photovoltaic solar cells are a much more promising technology. They provide a simple way to transform light directly into energy. This article will examine how this technology works at a basic level while also accessing the benefits and possible problems of this technology. It will also examine possible technologies in the future to try to overcome these problems. How photovoltaic solar cells work: A photovoltaic cell uses a semiconductor material to convert light into electrical energy. Photons of light striking the material excite the electrons, freeing them from their atoms in the material. Once excited, the electrons can move freely within the material. The semiconductor is then used to force the electrons in the desired directions. By creating a junction of ap and n type semiconductors, an electric potential is created. Electrons move from n-type to p-type. During this time, positively charged atoms change from p-type to n-type. As a result, the N-type material acquires a positive charge and the P-type material acquires a negative charge. When an electrical circuit connects the P-type and N-type ends, the difference between the middle of the paper and conventional energy. This presents promising chances of reducing carbon dioxide emissions and thus reducing global warming. But it cannot compete economically with current energy means and, therefore, more research must be devoted to this cause so that its benefits are fully realized. Works Cited Berinstein P. 2001. Alternative energy: facts, statistics and issues. Westport (CT): Oryx Press; 208p. Current solar systems: modern photovoltaic solar cells. http://www.personal.psu.edu/users/t/s/tss178/pvcells.htm [October 19, 2004] Ramage J. 1997. Energy, A Guidebook. New York: Oxford. 194p. Sorensen B. 2000. Renewable energy: its physical, engineering, use, environmental impacts, economics and planning aspects. 2nd ed. San Diego: Academic Press. 912p.http://www.worldbank.org/html/fpd/energy/subenergy/solar/solar_pv.htm [October 2004 18]