On characterization and measurement of average solar field mirror reflectance in utility-scale concentrating solar power plants

Due to the emerging need for the development of acceptance test codes for commercial concentrating solar power (CSP) plants, an effort is made here to develop a mirror reflectance model suitable for CSP applications as well as a general procedure to measure the average mirror reflectance of a solar field. Typically, a utility-scale solar field includes hundreds of thousands of mirror panels (if not more), and their reflectance is subject to many factors, such as weather and planned washing schedule. The newly developed mirror reflectance model can be used to characterize different types of mirror materials and can be directly used to perform optical performance evaluation of solar collectors. The newly proposed procedure for average solar field reflectance measurements includes a baseline comprehensive measurement and an individual factor measurement: the former allows a comprehensive survey of mirror reflectance across the whole solar field, and the latter can provide correcting factors for selected individual factors to further improve the accuracy of the baseline measurements. A detailed test case implementing the general procedure is applied to a state-of-the-art commercial parabolic trough plant and validates the proposed mirror reflectance model and average reflectance measurement procedure. In the test case, the plant-wide reflectance measurements at a commercial utility-scale solar plant were conducted and can shed light on relevant analysis of CSP applications. The work can also be naturally applied to other types of solar plants, such as power towers and linear Fresnel plants.

[1]  Jesús Fernández-Reche,et al.  Reflectance measurement in solar tower heliostats fields , 2006 .

[2]  D. Kearney,et al.  Chapter 6: Recent Advances in Parabolic Trough Solar Power Plant Technology , 2005 .

[3]  A. Hardy,et al.  The principles of optics , 1932 .

[4]  F. E. Nicodemus,et al.  Geometrical considerations and nomenclature for reflectance , 1977 .

[5]  R. B. Pettit,et al.  Characterization of the reflected beam profile of solar mirror materials , 1977 .

[6]  Stephanie Meyen,et al.  Parameters and method to evaluate the solar reflectance properties of reflector materials for concentrating solar power technology - Official SolarPACES reflectance guideline verstion 2.5 , 2013 .

[7]  Giampaolo Manzolini,et al.  Geometric analysis of three-dimensional effects of parabolic trough collectors , 2013 .

[8]  Chuck Kutscher,et al.  History, current state, and future of linear Fresnel concentrating solar collectors , 2014 .

[9]  M. Montecchi.  Approximated method for modelling hemispherical reflectance and evaluating near-specular reflectance of CSP mirrors , 2013 .

[10]  D. Mills.  Advances in solar thermal electricity technology , 2004 .

[11]  Ari Rabl,et al.  Active solar collectors and their applications , 1985 .

[12]  Eckhard Lüpfert,et al.  Advances in Parabolic Trough Solar Power Technology , 2002 .

[13]  R. N. Griffin,et al.  Determination of extraterrestrial solar spectral irradiance from a research aircraft. , 1969, Applied optics.

[14]  D. Kearney.  Utility-Scale Power Tower Solar Systems: Performance Acceptance Test Guidelines , 2014 .

[15]  Tim Wendelin,et al.  SolTRACE: A New Optical Modeling Tool for Concentrating Solar Optics , 2003 .

[16]  Guangdong Zhu,et al.  A New Optical Evaluation Approach for Parabolic Trough Collectors: First-Principle OPTical Intercept Calculation , 2012 .

[17]  P. Bendt,et al.  Optical Analysis and Optimization of Line Focus Solar Collectors , 1979 .

[18]  Michael Wagner,et al.  Acceptance Performance Test Guideline for Utility Scale Parabolic Trough and Other CSP Solar Thermal Systems: Preprint , 2011 .