A Polygeneration Process Concept for Hybrid Solar and Biomass Power Plant

Chapter 4Solar Thermal Power Plant

Solar thermal technology is emerging as one of the most promising options for power generation due to the depletion of fossil fuels and the growing concern about climate change. The conditions for utilizing solar energy are favorable in different countries due to the wide availability of solar radiation. Solar thermal technology concentrates solar rays to heat a fluid, which then directly or indirectly runs a turbine and an electricity generator. Concentrating the sun’s rays allows for the fluid to reach working temperatures high enough to ensure fair efficiency in turning the heat into electricity, while limiting heat losses in the receiver. Most installed capacities today replicate the design of the first commercial plants built in California in the 1980s, which are still operating. Long parabolic troughs track the sun on one axis, concentrate the solar rays on linear receiver tubes isolated in an evacuated glass envelope, heat oil to 390 °C, then transfer this heat to a conventional steam cycle. Almost half the facilities built in Spain since 2006 have been equipped with thermal energy storage comprised of two tanks of molten salts with 7 hours of nominal capacity (i.e. with full storage they can run seven hours at full capacity when the sun does not shine). This is now fully mature technology. In the United States, three 280 MW (gross) plants using PTC technology were built and connected to the grid in 2013 and early 2014: two without storage, ...