Session: 05-05 Solar Receiver Design 3

Paper Number: 112266

112266 - Assessing the Optical Performance Impact of Tracking Error in an Operational Concentrating Solar Power Plant Using Monte Carlo Ray-Tracing Simulation 

Concentrating Solar Power (CSP) provides firm and dispatchable electricity due to its thermal storage and hybridization capabilities, which supports the decarbonization of our energy supply. Of the various CSP technologies, parabolic trough collectors are the most mature, with over 500 MW operating worldwide. The optical performance of parabolic trough systems is sensitive to tracking error, which is defined as the angular offset of a collector away from the sun position in the transversal plane. Tracking error commonly occurs due to non-continuous adjustment of the trough angle to point toward the sun, but other factors such as gravity, heating, and wind loading can also contribute to tracking error. Researchers have explored the impact of tracking error on optical performance both numerically and experimentally, but existing studies do not include measurements from operational utility-scale power plants. Tilt angle measurements of parabolic troughs at operational utility-scale power plants illustrate spatial variations in optical performance and include various sources of tracking error such as gravity, heating, and wind loading.

To fully characterize wind driven loads on parabolic troughs, we are conducting a long-term field measurement campaign at the Nevada Solar One CSP plant located in Boulder City, NV, which has a nominal capacity of 72 MW and 0.5 hours of full-load storage. We record load measurements on four outer trough rows, collecting support structure bending moments, drive torque moments, dynamic accelerations of the spaceframe, mirror displacement, and tilt angles. Using the tilt measurements acquired at 20 Hz frequency, we calculate the deviation between the nominal sun position and the tracker angle. Using a Monte-Carlo ray-tracing simulation software, we assess the impact of the tracker angle deviation on optical performance throughout the diurnal cycle at various spatial locations within the CSP plant. In our view, this first-of-a-kind study will provide important guidance for future trough designs that reduce the impact of various sources of tracking error on performance.

Presenting Author: Brooke Stanislawski National Renewable Energy Laboratory (NREL)

Presenting Author Biography: Brooke works to advance renewable energy technologies through numerical modeling of physical processes such as fluid mechanics, turbulence, heat transfer, and structural loading. She earned her B.S. in Mechanical Engineering at Northwestern University and her Ph.D. in Mechanical Engineering at University of Utah. As a postdoctoral researcher, she works on projects in wind, solar, and hybrid power plant applications. In solar energy, she works in Concentrated Solar Power (CSP) modeling optical losses, wind loading, and the turbulent inflow in the atmospheric boundary layer. During her Ph.D., she used large-eddy simulations to develop cooling solutions for utility-scale solar photovoltaic (PV) plants to improve performance as part of the DOE SunShot Initiative.