Session: 4.1.4 - Renewable Energy Systems

Paper Number: 108839

108839 - Start-Up Operation Strategy Optimization of the Solar Field for a Parabolic Trough Concentrated Solar Power Plant 

Solar energy is a renewable energy source with wide abundance and low carbon emission. It can replace fossil fuels to reduce air pollution and save resources. Concentrated solar power (CSP) integrating thermal energy storage (TES) is one of the technologies to utilize solar energy, and is the only one with a highly dispatchable feature. Among various CSP technology categories, parabolic trough concentrated solar power (PTCSP) is the most mature and dominant in the market. It focuses concentrated sunlight on a linear receiver. Nevertheless, due to the intermittency of solar energy, PTCSP undergoes daily start-ups and shut-downs despite integrating the TES. It reduces the annual electricity production of PTCSP by 10% to 20%, and increases its levelized cost of energy (LCOE). The energy analysis on the PTCSP during the start-up process indicated that the start-up energy loss of the PTCSP with 50 MW capcity consists of collector optical loss, steam turbine cold source loss, receiver heat loss, bypass steam loss and collector defocused loss, and nearly 30% energy loss has energy-saving potential by optimizing the system configuration and operational strategy. However, research on reducing the start-up energy consumption of CSPs does not draw enough attention. Here, the start-up strategy of the solar field was optimized to reduce the start-up energy consumption. The solar field is divided into two sections with different start-up strategies. The start-up strategy of the first section employs the conventional solar field start-up strategy, and the start-up strategy of the other section is modified based on the power block start-up curve, which reduces the collector temperature of the solar field. The results indicate that the energy and exergy of TES can be improved by 9.4% and 11.4%, respectively, by optimizing the solar field start-up strategy. The increase in TES energy storage is due to the reduction of collector heat loss and receiver defocused loss. The increase in TES exergy storage is due to the reduction of collector heat loss, receiver defocused loss, and the heat transfer exergy loss of the steam generation system. The annual performance analysis of PTCSP shows that the annual electricity production can be improved by 171.1 MWh (~0.1%), and the annual net income is approximately 30000 $ when the feed-in tariff is 0.16 $/kWh. This work can lay a foundation for the energy-saving optimization of PTCSP plants during start-up processes, which can reduce the LCOE and enhance the market competitiveness of the PTCSP plants.

Presenting Author: Shunqi Zhang Xi'an Jiaotong University

Presenting Author Biography: Shunqi Zhang is a Ph.D. candidate at Xi'an Jiaotong University. His research focuses on the energy analysis and operating optimization of the parabolic trough concentrated solar power plant during the start-up process.