Solar Resource for High-Concentrator Photovoltaic Applications

Abstract

Direct solar radiation is the main fuel for concentrating photovoltaic (CPV) technologies. At any instant, the magnitude and spectral distribution of incoming direct normal irradiance (DNI) on the concentrator determines the instantaneous power produced by the generator. On a seasonal or mean annual basis, the magnitude of the DNI resource also directly affects the design of the whole system. Therefore, detailed knowledge of the available solar resourceessentially in terms of broadband DNI-is required at the system's design stage to evaluate the anticipated power to be produced by the projected CPV plant. This chapter is devoted to providing a better understanding of the current methods used in solar resource assessment to accommodate the specific needs of CPV projects. To this aim, the chapter starts with an introductory discussion on extraterrestrial solar radiation and its transfer throughout the Earth's atmosphere. Later on, the most common solar radiation modelling approaches for solar energy applications are discussed preceding a brief review of the best current measuring techniques and data quality-control methods for solar radiation. This includes important measurement recommendations for CPV applications. The chapter ends with brief discussions on spectral and circumsolar solar radiation.

Worldwide multi-model intercomparison of clear-sky solar irradiance predictions

“…Therefore, the most common practice to assess the local solar energy potential is to rely on synthetic datasets of solar irradiance generated from weather models or direct processing of satellite imagery [2]. This latter approach represents the current state-of-the-art in solar radiation modeling for solar energy applications [3]. Although the interaction between clouds and solar radiation overwhelms all other interactions, model data accuracy is also highly relevant in the absence of clouds because STE power production requires cloud-free conditions.…”

Worldwide impact of aerosol’s time scale on the predicted long-term concentrating solar power potential

“…In particular, in the absence of clouds, aerosol is the key atmospheric constituent that controls most of the attenuation of solar radiation throughout the atmosphere, and thus the resulting surface irradiance. Aerosol loads may reach levels yielding up to ≈70% DNI extinction, or even higher under extreme circumstances, over highly-turbid regions 21 . Consequently, the uncertainty in solar resource assessments over low-cloudiness areas is essentially determined by the uncertainty in the description of the aerosol optical properties.…”