SOLAR THERMAL FOR HEATING AND COOLING

The total area of installed solar collectors (i. e., non-electric solar thermal) amounted to 185 GWth by early 2010 (REN21, 2011). Of which China, Germany, Turkey and India accounted for 80.3%, 3.1%, 1.8% and 1.1% respectively. The remaining 13.7% was accounted for other 40 plus coun­tries including the USA, Mexico, India, Brazil, Thailand, South Korea, Israel, Cyprus, Ethiopia, Kenya, South Africa, Tunisia, and Zimbabwe. Three types of solar collectors (i. e., unglazed, glazed flat-plate and evacu-

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ated tube) are found in the market. By the end of2009, of the total installed capacity of 172.4 GWth, 32% was glazed flat-plate collectors; 56% was evacuated tube collectors; 11% was unglazed collectors; and the remain­ing 1% was glazed and unglazed air collectors (Weiss et al., 2011).The market for solar cooling systems remains small although it is growing fast. An estimated 11 systems were in operation worldwide by the end of 2009 (REN21, 2011). The use of solar thermal non-electric technologies var­ies greatly in scale as well as type of technology preferred. For instance, the market in China; Taiwan, China; Japan; and Europe is dominated by glazed flat-plate and evacuated tube water collectors. On the other hand, the North American market is dominated by unglazed water collectors em­ployed for applications such as heating swimming pools.