How are Solar Hot Water collectors different from Photovoltaic (PV) panels?
Photo-voltaic cells (PV) use semiconductor-based technology to convert light energy directly into an electric current that can either be used immediately, or stored in a battery, for later use. PV panels are now becoming widely used as they are very versatile, and can be easily mounted on buildings and other structures. They can provide a clean, renewable energy source which can supplement and thus minimize the use of mains electricity supply. The disadvantage of PV panels is their high cost and relatively low energy conversion rate (only 13-15%). Thermal energy can be used directly to heat water for household use. In many regions, solar water heaters are now a viable supplement or alternative to electric or gas hot water production. Thermal energy obtained from the sun can be used for a number of applications including producing hot water, space heating and even cooling via use of absorption chilling technology. Thermal solar has average efficiency levels of 60-75% (4-5 times PV effic
