Photovoltaic (PV) Module and Its Lifespan

Photovoltaic (PV) cells are transistors or integrated circuits on steroids. Most people have seen the latest microcomputer chip used in PCs. It's a silicon wafer about the size of your thumbnail that holds several millions transistors and other electronic parts. PV cells start out the same way circuits, but they are kept in the oven until they are much larger, approximately 10 cm in diameter. The baked silicon rods are sliced into wafers which are polished and assembled with interconnecting electrical wires. A grouping of PV cells which are arranged in a frame is called module.

Almost all photovoltaic module manufacturers provide a written guarantee for 20 to 25 years or more. The manufacturers are obviously quite sure that their products will stand the test of time. The reason for this certainty is the same one that explains why old transistor radios last so long. The semiconductor technology of the cell wafer results in very little wear and degradation.

The standard warranty term from siemens states that any module that loses more than 10 % power output within 10 years or 20 % within 25 years will be repaired or replaced. (This is known as a limited liability warranty, more commonly known as the fine print; be sure to read this detail carefully to ensure you understand the warranty terms.) Cell technology and quality of workmanship are very high in the industry, so be sure to purchase cells with the best possible warranty for your money.

The cells themselves are quite fragile. To protect them from damage and weather, the cells are bonded to a special tempered-glass surface and sealed using a strong plastic backing material. (Laminated or flexible "roof shingle" systems replace the glass surface with a tough, flexible polymer). The entire module is inserted into an aluminum, non-corroding housing to form the finished assembly. Once a grouping of modules, called an array, is mounted to a roof or to a fixed or tracking rack, it should stay put forever.

Elieser Tarigan is an expert on solar energy technology. He has written several articles on solar thermal, solar electricity technologies, and other green energy. To learn more about him, visit his site: http://netfinest.com