摘要
INTRODUCTION Photovoltaic(solar)cells(Corkish 2004)are semiconductor devices that directly create electric current and voltage from the collection of photons(quanta of light).They convert sunlight to electricity silently and without moving parts,require little maintenance,are reliable,are being sold with warranties of up to twenty-five years,generate no greenhouse gases in operation,and are modular,rapidly deployable and particularly suited to urban rooftops,façades,and similar applications.Hence,they are easily located close to where electricity is consumed.
