Solar Radiation

An Introduction to Solar Radiation is an introductory text on solar radiation, with emphasis on the methods of calculation for determining the amount of solar radiation incident on a surface on the earth. Topics covered include the astronomical relationship between the sun and the earth; thermal radiation; the solar constant and its spectral distribution; and extraterrestrial solar irradiation. This book is comprised of 12 chapters and begins with an overview of the trigonometric relationships between the sun-earth line and the position of an inclined surface, followed by a discussion on the characteristics of blackbody radiation. The next chapter focuses on the solar constant and its spectral distribution, paying particular attention to extraterrestrial solar spectral irradiance and the sun's blackbody temperature. Subsequent chapters explore extraterrestrial and radiation incident on inclined planes; the optics of a cloudless-sky atmosphere; solar spectral radiation and total (broadband) radiation under cloudless skies; and solar radiation arriving at horizontal surfaces on the earth through cloudy skies. The ground albedo and its spectral and angular variation are also described, along with insolation on inclined surfaces. The last chapter is devoted to instruments for measuring solar radiation, including pyrheliometers and pyranometers. This monograph will serve as a useful guide for energy analysts, designers of thermal devices, architects and engineers, agronomists, and hydrologists as well as senior graduate students.

The sun radiates a tremendous amount of energy, called solar energy or solar radiation, which is the main natural source of energy on the Earth, by far. Because solar radiation is the almost unique supplier of energy to the Earth, it has a primary influence on life and activities on the Earth. The climate is a first example, but there are many others, such as plant growth or human health, or even the design of buildings, the production of energy, notably electrical and thermal, or even aging materials. This book aims to provide simple answers to anyone who has questions about solar radiation. Its ambition is to help by presenting the fundamental elements of the solar radiation received on the ground. The book includes many examples and numerous illustrations, as well as some simple but fairly precise equations to calculate the various elements covered and to reproduce the figures and graphs. The first of the three parts of this book is devoted to the relative geometry between the direction of the sun and an observer on the ground as well as to the solar radiation emitted by the sun and received at the top of the atmosphere. The orbit of the Earth around the sun and the solar declination are described. The concept of time is introduced which is closely linked to the solar cycle and the rotation of the Earth on itself. Equations are given to calculate the solar radiation received on a horizontal or inclined surface located at the top of the atmosphere. The spectral distribution of the extraterrestrial solar radiation is described. The second part of this book addresses how the solar radiation incident at the top of the atmosphere is attenuated and modified in its downward path to the ground. The reflection of the radiation by the ground is presented. The solar radiation received on the ground by a horizontal or inclined collector plane, such as a natural slope or a rooftop, is discussed, as well as its spectral distribution. The variability of the radiation is addressed in relation to the properties of solar radiation estimated from the measurements. The third part deals with direct or indirect measurements of the solar radiation received on the ground over a given integration time (minute, hour, day, or month), whether for total radiation or radiation in a spectral range such as ultraviolet (UV), or daylight, or photosynthetically active radiation (PAR). It also explains how to check the plausibility of the measurements. Fundamentals of Solar Radiation will be a valuable resource to all professionals, engineers, researchers, students, and other practitioners that seek an understanding of solar radiation.

Solar radiation data is important for a wide range of applications, e.g. in engineering, agriculture, health sector, and in many fields of the natural sciences. A few examples showing the diversity of applications may include: architecture and building design, e.g. air conditioning and cooling systems; solar heating system design and use; solar power generation; evaporation and irrigation; calculation of water requirements for crops; monitoring plant growth and disease control; skin cancer research.

Written by a leading scientist with over 35 years of experience working at the National Renewable Energy Laboratory (NREL), Solar Radiation: Practical Modeling for Renewable Energy Applications brings together the most widely used, easily implemented concepts and models for estimating broadband and spectral solar radiation data. The author addresses various technical and practical questions about the accuracy of solar radiation measurements and modeling. While the focus is on engineering models and results, the book does review the fundamentals of solar radiation modeling and solar radiation measurements. It also examines the accuracy of solar radiation modeling and measurements. The majority of the book describes the most popular simple models for estimating broadband and spectral solar resources available to flat plate, concentrating, photovoltaic, solar thermal, and daylighting engineering designs. Sufficient detail is provided for readers to implement the models in assorted development environments. Covering the nuts and bolts of practical solar radiation modeling applications, this book helps readers translate solar radiation data into viable, real-world renewable energy applications. It answers many how-to questions relating to solar energy conversion systems, solar daylighting, energy efficiency of buildings, and other solar radiation applications.

The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operation, and maintenance Data quality assessment Methods to use measured data to estimate irradiance for any surface With a broad range of content that will benefit students and more experienced readers alike, this resource serves as a primer and technical reference that presents the basic terminology and fundamentals for resource assessment. It explores the history of solar radiation instruments and addresses direct normal, global, diffuse, and tilted measurements, as well as the characteristics of instruments used for these measurements. The authors consider methods of assessing the uncertainty of solar measurements and then cover albedo, infrared, net, and spectral irradiance measurements and instrumentation. The book devotes a section to other meteorological instruments, and another to the basics for installing and operating a solar monitoring station. Appendices include information on solar resource assessment modeling and satellite-derived irradiance, along with other useful material. This book’s authors are experts who each have more than 30 years of experience developing and operating multiple measurement stations, working with industry to improve radiometry, and conducting various research projects.

The cost of operating a building far exceeds the cost of constructing it, and yet until recently little attention was paid to the impact of solar radiation on the costs of heating, cooling and ventilation. And now that there has been a surge in interest in energy efficiency and solar design, architects and designers need a practical guide to the modelling and application of solar energy data. There are many different models and techniques available for calculating the distribution of solar radiation on and in buildings, and these algorithms vary considerably in scope, accuracy and complexity. This book demonstrates which of these predictive tools gives the best results in different circumstances, including explaining which models can be best used in different parts of the world. The author has had over twenty-five years of experience of dealing with solar energy data from four continents and has used that experience in this book to show the development not just of knowledge but also the growing sophistication of the models available to apply it.

This book includes up-to-date and detailed information on fundamental principles, measurement, modeling, and forecasting of solar radiation for technologies and applications of photovoltaic (PV) solar energy. The book also presents basic, modern, and contemporary knowledge and techniques of reliability and performance assessment for PV systems. It includes eleven chapters in four sections: “Introduction”, “Fundamentals, Measurements and Modeling of Solar Radiation”, “Forecasting and Characterization of Solar Radiation”, and “Solar Photovoltaic Technologies and Applications”. Chapters address such topics as fundamental principles, accurate measurements, and modeling of solar radiation; innovative methods for forecasting and characterization of solar radiation; PV technology and application, from conventional and emerging PV technologies to bifacial PV cells and modules and concentrator PV systems; and recent advances in reliability and performance assessment for PV systems, including outdoor characterization, degradation analysis, and PV power prediction.