OverviewHigh-temperature collectorsHistoryLow-temperature heating and coolingHeat storage for space heatingMedium-temperature collectorsHeat collection and exchangeHeat storage for electric base loads
Where temperatures below about 95 °C (200 °F) are sufficient, as for space heating, flat-plate collectors of the nonconcentrating type are generally used. Because of the relatively high heat losses through the glazing, flat plate collectors will not reach temperatures much above 200 °C (400 °F) even when the heat transfer fluid is stagnant. Such temperatures are too low for efficient conversion
Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry, and in the residential and commercial sectors. Solar thermal collectors are classified by the United States Energy Information Administration as low-, medium-, or high-temperature collectors.
Heat energy is preferred as compared to electrical energy to meet the energy requirement of various applications in the process industries. Therefore, the solar thermal energy system is considered to be one of the attractive solutions for producing thermal energy for process heat applications.
The efficiency of low temperatures solar thermal systems such as flat plate collector (FPC), evacuated tubular collector (ETC), solar pond (SP), and solar chimney (SC) are in the order of 15–40% and the medium temperature solar systems such as linear Fresnel reflector (LFR) and parabolic trough collector (PTC) are in the order of 50–60%.
While solar PV power generation has gained rapid momentum and is highly efficient for power generation, solar thermal applications, including both CSP and direct solar heat applications, offer a range of advantages for addressing specific energy needs in industrial, agricultural, residential, and commercial sectors.
This chapter also covers the recent developments in solar thermal technologies for power generation. In recent times, solar thermal technologies are integrated with conventional fossil-fuelled power plants as well as other renewable energy sources such as biomass, geothermal to improve its performance.
Kalogirou (2003) analyzed the characteristics and economics of solar thermal energy systems such as flat plate, evacuated tubular, compound parabolic, and parabolic trough collectors for industrial applications such as paper, textile, chemical, food, and beverage industries (temperature range from 60 °C to 260 °C).