Solar Energy in Buildings

Thermal Balance for Efficient Heating and Cooling

Dorota Chwieduk

• Publisher: Academic Press
• Year: 2014
• ISBN:
  9780124105218
• Topic: Technology & Engineering
• Subtopic: Renewable Power Resources
• Index: Technology & Engineering

Solar Energy in Buildings presents solar radiation fundamentals and their applications in buildings, supported by theoretical analysis and results of original simulation studies in solar energy availability, collection, and conversion for both active and passive use. In-depth coverage of energy balance and heat transfer in building envelopes is supported by the inclusion of calculations and case studies, while contextualizing within an integrated design approach.

• Explains the best uses of cutting-edge advances such as concentrated solar thermal, thermoelectric and polymetric materials
• Covers active and passive solar collection and conversion systems
• Provides energy balance calculations and case studies deriving from real installations connect theory and practice

Chapter 1

Solar Radiation—Fundamentals

Abstract

This chapter gives the terminology utilized in reference to the solar energy use. It defines key characteristic parameters describing solar radiation. Spectral distribution of solar radiation is presented and discussed. The chapter also covers physical fundamentals of selected phenomena related to solar radiation and its travel to the Earth's surface, including attenuation caused by the Earth’s atmosphere. Processes of scattering and absorption of solar radiation by atmosphere particles are described in detail. The phenomena of the greenhouse effect is also presented and analyzed. Determination of the sky temperature according to the Swinbanck model is explained. The final section presents classification of key technologies that utilize, in a direct or indirect way, solar energy.

Keywords

Greenhouse effect; Key solar energy technologies; Scattering and absorption of solar radiation; The sky temperature; Solar energy terminology; Solar radiation fundamentals; Spectrum of solar radiation

1.1. Terminology

Solar energy terminology is systematized in the standard ISO 9488 “Solar energy—Vocabulary” [1]. This section describes certain selected terms related to solar energy, which will be used throughout this publication. Vocabulary used in this book is consistent with the above-mentioned standard.

Solar radiation is characterized by various parameters. Certain vocabulary incompatibilities may be observed in publications on solar energy and civil engineering. Vocabulary related to the description of solar energy quantities was proposed in the 1980s by Duffie, Beckman, and Klein in one of the best known publications on solar energy fundamentals [2]. In numerous later publications, vocabulary varied, depending on the research center involved. In 1999, standard EN ISO 9488:1999 [1] concerning solar energy vocabulary was published in order for it to be standardized. Vocabulary given below is defined according to this standard.

Solar radiation is radiation emitted by the Sun, whereas solar energy is the energy emitted by the Sun in the form of electromagnetic waves. According to the EN ISO 9488 standard, solar energy may also be understood as any energy available thanks to collecting and converting solar radiation.

Global solar radiation is the solar radiation incident on the horizontal Earth’s surface. According to the EN ISO 9488 standard, the global radiation term may only be applied to a horizontal surface. In case of any tilted surface, the term hemispherical radiation should be used instead. In fact, the global radiation is a case of hemispherical radiation too, but only that which reaches the horizontal Earth’s surface. Hemispherical solar radiation incident on a horizontal surface consists of beam radiation (also known as direct radiation) and radiation scattered by the atmosphere. Beam radiation is incident at small solid angle starting from the Sun's disk.

Hemispherical radiation is radiation received from the entire hemisphere above (i.e., solid angle 2 π sr). Hemispherical solar radiation incident on a tilted surface consists of direct and scattered radiation, as well as radiation reflected by the ground. Scattered and reflected components form diffuse radiation that reaches any tilted surface. Diffuse radiation may be determined as hemispheric radiation minus beam radiation.

Radiant energy is the amount of energy carried by radiation. The radiation itself is energy emission or transfer in the form of electromagnetic waves. Radiant energy flux (radiant flux, flux of radiation) is the total power emitted, transferred, or received in the form of radiation. Then, irradiance is a power density of radiation incident on a surface (i.e., the amount of incident energy in the time unit-per-unit area of the given surface).

Spectral solar irradiance is irradiance for a specific wavelength (i.e., irradiance of monochromatic solar radiation). Solar spectrum is presented as a spectral solar irradiance function of radiation wavelength.

Radiant exitance is the radiant flux leaving a unit area of a surface in the form of emission, reflection, or transmission. Then, radiant self-exit...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Acknowledgments
• Introduction
• Chapter 1. Solar Radiation—Fundamentals
• Chapter 2. Availability of Solar Radiation on the Earth
• Chapter 3. Shaping Building Envelope with Regard to Incident Solar Radiation
• Chapter 4. Photothermal Conversion in a Building
• Chapter 5. Passive Utilization of Solar Energy in a Building
• Chapter 6. Energy Balance of a Building with Regard to Solar Radiation Exposure
• Chapter 7. Active Solar Systems in Buildings
• Chapter 8. Buildings “Aware” of Solar Energy Impact: Summary
• Index