Session: 18-01 HelioCon Metrology

Paper Number: 141827

141827 - Heliostat Consortium: Scoping Optical Metrology Tools for Heliostat Evaluation and Building a Power Tower Concentrating Solar Power Plant Database 

Abstract: 

Concentrated solar power (CSP) technology, which uses mirrors to concentrate sunlight onto a receiver to be converted to thermal energy, has been a renewable energy source for decades and it has the potential to provide dependable and dispatchable electricity while reducing greenhouse gas emissions. A heliostat is a significant component of power tower CSP plants, which is a mirror that tracks the movement of the sun, reflects, and focuses the sunlight on a receiver target on top of the solar tower. Precise tracking enables the effective concentration of solar energy throughout the day, and optimization of the thermal energy delivered to the receiver, where it is converted into electricity or stored for later use. Therefore, it is important to accurately measure and characterize the performance of heliostat and heliostat’s relevant properties. Optical metrology tools are essential for evaluating heliostat systems in CSP plants as they ensure precise alignment and optimal focus of sunlight and enhancing the efficiency and performance of solar energy generation. A scoping study under the Heliostat Consortium (HelioCon) was presented on optical metrology tools for heliostat evaluation, which could help the CSP community to find the appropriate tools to meet their needs and be a reference for future product development. The current available tools for evaluating the performance of heliostats were investigated and categorized into five categories, which are solar-weighted specular reflectance measurement, opto-mechanical errors measurement, heliostat shape measurement, atmosphere attenuation and sunshape measurement, and wind load measurement. For each tool, the general description, products cost, maturity, operational information and limitation, and accuracy/uncertainty were collected. In addition to the scoping study on metrology tools for heliostats, an online power tower CSP plant database has been created to share plant information to the public, which includes the plant construction and operation timeline, heliostat design, tower design, and solar field design information of current existing CSP tower plants and the images of solar field, heliostats, power tower/receiver and layout of the corresponding CSP plant. Any available additional information, such as lessons learned and environment conditions, are also included. Furthermore, available monthly, quarterly, and annual generation data were also collected. Currently, information for 43 power tower CSP plants is available in the database. This online database provides a centralized, accessible repository of information regarding relevant details of CSP worldwide, which should be able to facilitate research, analysis, and decision-making for stakeholders and help newcomers who are interested in CSP tower plants find general design and operational information on existing CSP tower plants around the world.

Presenting Author: Yu Zhou National Renewable Energy Laboratory

Presenting Author Biography: Yu Zhou is a post graduate intern in the Thermal Energy Systems group at NREL, holding a MS degree in Mechanical Engineering with a concentration in Thermofluids at Northeastern University and BS degree in Mechanical Engineering at University of New Hampshire. Her MS degree thesis was on requirement for seasonal energy storage with only solar and wind as energy sources, which is being furthered at NREL. Beside the research on seasonal energy storage topic, she is also working on the HelioCon project. Under the HelioCon project, Yu is helping with building the HelioCon Database and the scoping study on optical metrology tools for heliostat evaluation.

Authors:

Yu Zhou National Renewable Energy Laboratory
Rebecca Mitchell National Renewable Energy Laboratory
Guangdong Zhu National Renewable Energy Laboratory