Electricity generators, solar thermal

The first solar-electric technology to arouse industry interest was solar-thermal energy (1,3,5,6,8). Under favorable circumstances, it can be cost-effective, as evidenced by the fact that solar-thermal gas-hybrid plants produce over 350 MW of commercial power in southern California. This power is used during peak demand to supplement that available from conventional generation. 

Three main types of concentrating collectors have evolved for use in solar thermal systems low concentration paraboHc troughs, high concentration parabohc dishes, and central receivers (Fig. 3). Higher concentration produces higher temperatures in a working fluid and makes electrical generation more efficient. 

Wind, solar thermal, and photovoltaic power together accounted in 1998 for only about 1% of U.S. electricity generation from renewable sources and only about 0.1% ofall electricity (DOE/EIA 1999a). 

Wind is the motion of air masses caused by the different thermal conditions that occur over the earth s surface as a result of the transmission of solar radiation. Wind energy is defined as the kinetic energy of the wind converted into mechanical work. This mechanical work can be used to drive an electrical generator for the production of electricity. A machine that performs this conversion is called a wind turbine generator (WTG) and a group of these, including the auxiliary equipment, constitute a WF. 

SOLAR THERMAL ELECTRIC GENERATION PRODUCES ELECTRICITY... 

A solar thermal electric-generation unit. A pipe containing synthetic oil is positioned along a mirror-coated trough. Sunlight hitting the mirror is reflected onto the pipe and heats the oil to 370°C. The hot oil is then pumped out and used to convert water to steam in a turbine in an electric power plant. 

Solar thermal and photovoltaic electricity net generation (converted to Btu using the fossil-fueled plants heat-rate), and solar thermal direct use energy. 

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