Photovoltaic Efficiency : The ratio of electric power produced by a cell at any instant to the power of the sunlight striking the photovoltaic cell. This is typically 9% to 14% for commercially available cells
Young & Company Electric Power Products and Related Engineering Services, Glossary of Electrical Terms, http://www.youngco.com/young2.asp?ID=4&Type=3, CA., USA 2001. (Electr Sfty - Amer) {514}