The Solar Resource

TL;DR: In this article, the fundamental relationship of solar geometry, solar constant, and solar spectrum are given. And the most usable broadband solar radiation models and the basics for solar spectral modeling are discussed.

Abstract: This chapter deals with the fundamentals of solar radiation and solar energy. It consists of 12 sections and 4 appendices and bibliography. In the introduction section, a brief description of solar radiation as the principal source of energy for the Earth is provided. In the following sections, the necessary relationships of solar geometry, solar constant, and solar spectrum are given. The interference of solar radiation with the constituents of the atmosphere of the Earth is discussed. The most usable broadband solar radiation models and the basics for solar spectral modeling are discussed. The methods for testing the broadband solar models are presented. The basics of net solar radiation is explained. The need for the formation of networks of solar radiation stations and the generation of solar atlases are discussed. Some utility tools for easy solar-radiation calculations are provided. The last section describes the instruments for measuring solar radiation components with associated errors and uncertainties. The appendices provide the solar-constant values from 0.12 to 10 µm, the terms used in solar radiometry, the maximum wavelength of the solar spectrum considering the Sun as a blackbody and by applying Wien’s law, and the most usable physical constants and conversion factors between solar radiation units.