Alternative Energy: Solar Thermal Energy

Exploitation of non-renewable resources can create non-sustainable conditions and environmental degradation resulting in a significant loss of final product quality. Nowadays, in many industrialized countries, including the United States, the heating, cooling, ventilation, and lighting of buildings represent approximately 40% of the annual nation’s energy consumption. Therefore, it is first important to seek solutions that improve our quality of life, while reducing energy and environment consumption, then a fast transition to a structure based on renewable energy is of utmost importance. Solar thermal energy is an important alternative to fossil fuels with a huge potential. At the end of 2006, the solar thermal collector capacity in operation worldwide equalled 127.8 GW_th, corresponding to 182.5 million m². Of this, 102.1 GW_th were accounted for by flat-plate and evacuated tube collectors and 24.5 GW_th for unglazed plastic collectors. The installed air collector capacity was 1.2 GW_th. In terms of the total capacity in operation of flat-plate and evacuated tube collectors, installed at the end of the year 2006, China (65.1 GW_th), Turkey (6.6 GW_th), Germany (5.6 GW_th), Japan (4.7 GW_th), and Israel (3.4 GW_th) are the leading countries. The typical share of solar thermal energy necessary to meet the heating and cooling demands of a single building will be increased dramatically by more than 50%, and up to 100%. Without any doubt, solar thermal technology is already a mature technology, and its 30 years development has led to efficient and long life systems. In this entry, some different types of solar thermal collectors are presented, along with the design phases of a complete flat-plate collector plant. Although mature solar thermal technologies are already available, further developments are needed to provide adjusted products and applications, reduce the systems costs, and increase market deployment. Thus, innovative and cost-effective solar thermal systems are here presented and a description of a large solar thermal plant is given.