Optimization of concentrating solar thermal power plant based on parabolic trough collector

Concentrating solar power (CSP) plant with parabolic trough collector (PTC) using synthetic or organic oil based heat transfer fluid is the most established and commercially attractive technology. In this paper, extensive energy and economic analysis of PTC based CSP plants, without storage, are reported. Effects of turbine inlet pressure, turbine inlet temperature, design radiation, plant size, and various modifications of Rankine cycle on overall efficiency as well as levelized cost of energy are studied. Furthermore, the variation in optimal turbine inlet pressure with turbine inlet temperature, design radiation, plant size, and various modifications of Rankine cycle are also analyzed. Energy and cost optimal turbine inlet pressures for 1 MWe plant (with basic Rankine cycle) are about 4.5-7.5 MPa and 3.5-7.5 MPa, respectively. The optimum pressure is observed to be a weak function of design solar radiation. The overall efficiency increases and levelized cost of energy decreases with increase in turbine inlet temperature, plant size and various modifications of the Rankine cycle.