The process of capturing and using solar energy is as old as time. Like most things in the modern world, the simplicity of capturing the sun’s energy has been elevated to new technological heights. Unlike solar heating collectors that are used to warm fluids running within the collector, photovoltaic cells magically convert light form the sun directly into electricity. The photovoltaic cell used in renewable-energy systems is definitely the product of rocket scientists, powering communications satellites to ensure everyone on the planet can watch return of friends.
The term photovoltaic is derived from the Greek Language “photo”, meaning light, and “voltaic”, voltage which assists the flow of electricity. Friends simply call them “PV” cells for shorts. Bell laboratories discovered the PV cell effect in the 1950s. It didn’t take the folks at NASA very long to figure out the PV cells would be an ideal means of producing electricity in space. Many missions later, PV cells have improved in performance and have come back down to earth in price. Nowadays, the technology is used in watches, calculators, street signs, and renewable-energy systems for the urban homeowner.
Our sun has very generously decided to output a nice round 1,000 W of energy per square meter at noon on a clear day at sea level. In order to test the intensity of PV panels, Light sources have been developed that create this same level of light intensity or flux. The light is beamed onto the test PV panel, and its electrical ratings are recorded in the product data sheets. As a consumer, this greatly helps determine the value of one PV panel relative to another.
For the home renewable-energy system, solar module panels products are relatively standardized, allowing even a novice to make accurate comparisons between product lines. There are currently four major product technologies that should be seriously considered for home use: single crystalline, polycrystalline, laminate (roof shingles) and string ribbon cell. Other cell technologies such as “thin film” are an option provided product warranty and manufacturer financial strength to honor the warranty period are acceptable.
References: The Renewable Energy Handbook, by William H. Kemp.
Click the Image to BUY the BOOK
