Solar Energy: Let the Sun Shine In

CONTENTS

Dedication

Abstract

Introduction

Chapter 1     Solar Radiation and Planet Earth

Chapter 2     Solar Thermal Energy Systems

Chapter 3     Solar Photovoltaic Energy Systems

Chapter 4     Power Transmission and Distribution Systems

Chapter 5     Solar Energy Grid Integration System (SEGIS)

Chapter 6     The Impact of Solar Energy Production on the Environment

Chapter 7     Solar Geometry

Chapter 8     Solar Radiation

Chapter 9     Emerging Solar Energy Technology

Chapter 10   An Innovation in Solar Energy Technology

Chapter 11   The Future of Energy

References

DEDICATION

I dedicate this work to the two Sun’s that shone onto my solar collector for 41 years and dislodged my valent electrons to create the energy flow of learning that still guides all my life, Toby and Vera Graham.

MICHAEL ANTHONY GRAHAM

ABSTRACT

This great body through its great magnetic and gravitational pull holds all the planets and their related planetary bodies in their respective orbits within the boundaries of this solar system and the great volume of energy dispensed by the Sun throughout the solar system maintains the perpetual motion, correct interplanetary distances of the planets and life on Earth. This energy generated within the Sun through nuclear fusion (Hanania et al 2020) is not unique to the Sun in our Solar System as there are billions of other such stars throughout the Milky Way Galaxy and the universe (NASA) that have similar energy profiles and planets that orbit them that could similarly help to foster life in many other places if solar energy was all that was required for life.

INTRODUCTION

Fig I.1 Our Solar System. Source: NASA

The Earth exists as an integral part of a solar system that is a part of the Milky Way Galaxy which is one of many galaxies in a vast universe that is continually expanding and this vast universe consists of many solar systems and galaxies that are too numerous to count as there are billions of stars filling our universe. This makes the solar system in which the Earth exists relatively minute and physically insignificant except for the fact that this solar system and this galaxy is the only one in which life as humans know it is known to exists, even after many decades or maybe even many centuries of searching across the universe to find other life forms. The significance of this fact is that planet Earth with its varied life forms may be the only one of its kind in the universe and this awesome reality will not be diminished by much even if another planet which is an exact replica of Earth is located somewhere out there with life forms very similar to that on Earth, as this will only make Earth one of two in the universe of billions instead of only one in the same universe.

The Solar System in which the Earth exist consists of eight planets, many moons and an asteroid belt, all of which travel in different elliptical paths around a massive central yellow star which emits life giving energy on which all the planets within the system depend. In this solar system all of the planets rotate around the yellow star in a given path called an orbit, while the whole Solar System rotate around the Milky Way Galaxy. Each planet rotates around the yellow star, called the Sun, in a given orbit, at particular travel times and at set distances from the Sun and the travel time varies from 88 days for the smallest planet to orbit the Sun, to 225- 250 million earth years for the whole Solar System to orbit the Milky Way Galaxy (Earth-Sky 2016). The major elements of the Earth’s Solar System are the Sun and eight planets, namely Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, the moons that serve these planets and an asteroid belt. Each of the planets have the following characteristics (NASA):

•Mercury. This the smallest and the fastest planet with a radius of 1,516 miles, requiring only 88 Earth days to orbit the sun and it has the following characteristics, it is a terrestrial planet that is 36 million miles from the sun, day time temperatures of 430⁰ C, night time temperatures of -180⁰ C, it has no moon and no rings, has a rough rocky surface that is covered in craters and basins caused by meteoroid and comets crashing into it, it has a crust of basalt and silicates, a relatively large core made up of molten iron and an unbreathable atmosphere.

•Venus. This planet has a very thick atmosphere around it that acts to retain heat thereby making Venus the hottest planet and the basic characteristics of Venus are as follows, it is a terrestrial planet that is 67 million miles from the sun, has a radius of 3,760 miles, takes 225 Earth days to orbit the sun, has a surface temperature of 465⁰ C, spins backwards relative to the Earth (sun rises in the west and sets in the east), has no moons or rings, has a core of iron, a mantle of molten rock, a crust of thick rock and a surface made up of craters and could not support life due to its high temperatures and acidic clouds.

•Earth. For human existence this is the most favorably placed planet relative to the Sun and is the only planet with surface water and the ability to sustain life as it is known on planet Earth and the basic characteristics of earth are as follows, it is a terrestrial planet that is approximately 93 million mile from the sun, it has a radius of approximately 3,958 miles, it takes 365 days to orbit the sun, has surface temperatures that vary between -126 and 136 degrees F, has 1 moon and no rings, has an inner core of iron and nickel, an outer core of iron and nickel fluids, a mantle that is 1800 miles thick consisting of a hot mixture of molten rocks, a crust that varies between 19 and 3 miles at average land levels and the bottom of sea floors, a surface covered with mountains, valleys, plains, lakes, rivers, streams, ponds, volcanoes and a lithosphere crust plus upper mantle made up of moving plates and a protective shield in the atmosphere around it that breaks up meteoroids that enter the atmosphere before they hit the surface.

•Mars. One of the most intriguing planets with its proximity to the earth and the possibility that it may have and might be able to support life, as billions of years in the past the planet was both wet and warm unlike its current status. The basic characteristics of Mars are as follows, it is a terrestrial planet that is approximately 142 million miles from the Sun, has radius of 2106 miles, takes 687 Earth days to orbit the sun, has surface temperature that varies between -243 to 68 degrees F, has two moons and no rings, has a core of made up of iron, nickel and sulfur, a mantle of rocks which is between 770-1200 miles thick, a crust 6- 30 miles thick made up of iron, magnesium, aluminum, calcium and potassium and a surface that is rocky, dusty and red in appearance.

•Jupiter. The largest of the planets in the solar system with a very interesting visage, specifically it has a permanent large dark red storm, that is larger than the earth, located within it and the basic characteristics of Jupiter are, it is a Gas Giant, that is 477 million miles from the sun, has radius of 43,440 miles, takes 4,333 Earth days to orbit the sun, has a surface temperature of – 234 degrees F, unknown core, no crust, no solid surface, 75 moons and rings and an atmosphere made up of hydrogen, helium, ammonia, ammonium hydrosulfide and ammonium sulfide and does not support life.

•Saturn. This is a planet with large rings around it and the rings are the brightest, most massive and complex ring system of any planet and the basic characteristics of Saturn are, it is Gas Giant, that is 886 million miles from the Sun, has a radius of 36,183 miles, that takes 10,756 Earth days to orbit the sun, has a surface temperature of - 284 degrees F, a core that has never been observed, no crust or solid surface, has 53 confirmed moons, 29 others yet to be confirmed and rings, and has an atmosphere made up of ammonia clouds that does not support life.

•Uranus. One of the larger planets that is also quite interesting as it appears to tipped on its axis and the basic characteristics of Uranus are, it is a blue green Ice Giant, that is located 1.8 billion mile from the sun, with a radius of 15,759 miles, that takes 30,687 Earth days to orbit the sun, has 27 moons and 13 rings, has a surface temperature of – 356.8 degrees F, has a core of rocks and ice, has no crust, has a swirling liquid surface that turns to ice as it moves toward the core and an atmosphere made up of molecular hydrogen, atomic helium, methane, water and ammonia, that does not support life.

•Neptune. This planet is relatively large and has the distinction of being the only planet that was located first by mathematical calculation rather than by physical observations and the basic characteristics of this planet are, it is a blue Ice Giant, that is located 2,782 billion miles from the sun, with a radius of 15,299 miles, that takes 60,190 Earth days to orbit the sun, it has a surface temperature of – 353 degrees F, has 14 moons and 5 rings plus it has a small rocky core with iron, nickel and silicates, an atmosphere made up of molecular hydrogen, atomic helium and methane, that does not support life.

All eight planets, plus their moons and the asteroid belt, receive energy in several forms inclusive of gravitation pull, light and heat, from the giant star at the center of the solar system and this star, called the Sun, is quite massive relative to all of the 8 planets, 201 moons, ring materials and the asteroid belt that it serves, as it contains 99.8% of the total mass of the solar system (NASA). This great body, through its great magnetic and gravitational pull holds all the planets and their related planetary bodies in their respective orbits within the boundaries of this solar system and the great volume of energy dispensed by the Sun throughout the solar system maintains the perpetual motion, correct interplanetary distances of the planets and life on Earth. The energy that is utilized by the Sun is generated within the Sun through nuclear fusion (Hanania et al 2020), however, this is not unique to the Sun in our Solar System as there are billions of other such stars throughout the Milky Way Galaxy and the universe (NASA) that have similar energy profiles and the planets that orbit them could similarly help to foster life in many other places if solar energy was all that was required for life. The role of the Sun within the Solar System could be described as that of a great ring master that must continually rotate eight massive bodies in different planes, while maintaining perfect balance in perpetuity and also providing the required energy to each of these eight bodies need to sustain themselves. This juggling act must be maintained ad infinitum as it is quite probable that any major disturbance to any of these bodies could lead to the utter destruction of all the others including the ringmaster himself.

The energy provided by the Sun to the Earth is much more than the Earth could have ever used and this has always been the case from the early life of the Earth when there was no human, animal or plant life forms, up until the present time when the human population has grown to just over eight billion and is demanding even more energy everyday with its continuously growing numbers. This demand for more energy by humans was met in the past by the consumption of the many great forests which had existed from 400-500 million years ago in time, however, most of these forests were decimated and never regrew leaving barren wasted lands in their wake. The decimation of these forests forced humans to find and develop new energy sources and these new energy sources that were developed during a period of 150 -1000 years have all been proven to be a source of much harm to humans and the environment and they are forcing humans to once again seek and utilize new sources of energy, sources that will have fewer negative impacts on the planet and humans, than the current sources. There are currently several other sources that can be utilized, however, there is one source that is greatly underutilized even though it is more available in greater abundance everywhere than all of the other sources, it is free to use and has no negative impact upon the environment or human, this source is the energy from the Sun. This is a source of energy that has always been essential to life, but was never fully understood or fully utilized by humans, because until about one hundred and fifty years ago humans did not have the technology to fully optimized the energy that emanates from the Sun.

CHAPTER 1

Solar Radiation and Planet Earth

The Earth travels in an elliptical orbit around the Sun each Earth year, in approximately 365 Earth days, (Williams 2014) and in this orbit the earth is at one point closer to the Sun than throughout the rest of its orbit and at another point a little further from the sun. The point in the orbit where the earth is closest to the sun is usually referred to as perihelion, which is usually at a distance of approximately 89,729,825 miles (147,098,074 kilometers) from the sun and the Earth is usually in this position on January 3rd each year. The point in the orbit where the earth is furthest from the Sun, called the aphelion, which is usually at a distance of approximately 92,779,170 miles (152,097,000 kilometers) from the Sun and the earth is usually in this position on July 4th each year. When the Sun is in either of these positions, perihelion and aphelion, it will have different impacts upon the amount of solar energy that reaches the surface of the Earth and the difference in solar impact, impacts almost all life on the planet, as the shorter distance could mean warmer weather conditions and the longer distance usually mean colder weather conditions, however, this is not necessarily the case as January 3rd is usually very cold in the northern hemisphere and very hot in the southern hemisphere and July 4th is usually very hot in the northern hemisphere and very cold in the southern hemisphere.

The Sun’s impact upon the Earth is a function of several factors inclusive of the tilt of the Earth’s axis, 23.5⁰ off the vertical relative to the Earth’s plane of orbit, the direction in which the axis of the earth is pointed during its travel around the orbit, the distance from the Sun, the points at which the solar radiation most directly strikes the Earth, the equator, and the periodical changes in the Earth’s axial tilt, 22.1 -24.5,⁰ which occurs gradually over time every 26,000 years (Hocken 2019). The axial tilt of the Earth and the angle at which the Earth moves around the sun also determines the climatic conditions at different points on the surface of the Earth in an annual cycle, these climatic conditions include what are known as the four seasonal conditions that impacts the temperate regions of the planet. The conditions in the other regions of the Earth, the North Pole, The South Pole and the Tropical Region are also greatly impacted, with the Tropical region being continuously hot and the two polar regions, north and south, being continuously cold. A temperate region occurs on both sides of the tropical region and the four seasonal conditions also impact the temperate regions in the north and south of the planet at different times during the year, during the Earth’s orbit around the Sun. In the northern temperate region, the climatic conditions are cold from September to March and warm from April to August, while in the southern temperate region the climatic conditions are cold from April to August and warm from September until March each year. The different regions of the Earth also receive different amount of solar energy as the Earth orbits the Sun, depending on their latitudinal distance from the equator, with the greatest amount of solar energy impacting the equatorial regions of the Earth and the furthest distances, the North and South Poles receiving the least.

All of the planets are located at different distances from the Sun and the Earth along with the other planets receive different amounts of solar radiation based on their distance from the sun, their size, the planet’s atmosphere, the nature of their surfaces and according to the American Chemical Society (ACS) the energy supplied to the four terrestrial planets are as shown in the table below:

Table 1.1 Solar Energy Reaching the 4 Terrestrial Planets. Source: American Chemical Society

The meaning of the abbreviations as indicated in the table above are as follows:

•Dp – The distance of the planet from the sun in kilometers.

•sp – The energy flux at any place on the surface of the planet

•save – The average energy flux over the area of the planet

•save = sp/4

•The Earth’s energy flux, Sp, has a value ranging from 1370 – 1361 W/m², and is usually referred to as the solar constant for earth.

Solar Constant. The Earth like the other planets receive an average amount of solar energy per unit meter square of the Earth surface, this average amount of energy is referred to as the Solar Constant and the definition of the this constant is as follows- The Solar Constant is the radiant energy per cross sectional unit area that the Sun provides for the Earth’s systems and can also be described as "the total energy output of the Sun divided by the area (ASE) of the ‘Big Sphere’ as shown in Fig 1.3 below and as described by the equation - So = (3.87 x 10²⁶ W)/ASE = approximately 1368 W/m²

Ase = 4.pi. (Rse)²

Fig. 1.1 Solar Constant Big Sphere Diagram. Source: Publicasu.edu

1 AU = 1 astronomical unit, which is equal to 149.6 million kilometers, the mean distance from the center of the Earth to the center of the Sun.

Incident Solar Radiation

While the Earth is supplied with a constant source of energy not all of this incident energy is absorbed or otherwise utilized by the Earth as a fairly large portion of it is reflected,6% from atmosphere, 20% from clouds and 4 % from the surface of the Earth, a total of 30% of the incident energy is reflected back into space without positively impacting the Earth, leaving a balance of 70% of which 16% is absorbed by the atmosphere, 3% is absorbed by the clouds and 51 % is absorbed by lands and water. A significant portion of this energy that is absorbed by the land, water, cloud and atmosphere is also lost due to reradiation back into space. (Amin et al. 2020). The 51% that is absorbed by the land and surface waters is utilized by the Earth in many ways inclusive of the production of essential plant life, providing the driving force for the hydrologic cycle and the support of animal and human life, however, this 51 % is not always utilized in the most efficient manner and it is possible that with the right technologies much more of the Sun’s energy that reaches the surface of the earth could be better utilized to create new motive forces to better serve humans and the environment by replacing the existing energy sources which are currently used to drive industry, transportation, lighting, heating and cooling for industrial, commercial, residential, institutional, health and educational facilities. These other sources of energy are also directly dependent upon the energy from the Sun for their creation over a very long period of time, unfortunately however, these sources were created using the element called carbon, which if wrongly utilized can create many negative impacts on the conditions of the planet.

Historical Use of Solar Energy

Humans have always needed and utilized many things to create the heat and light energy that they needed for their everyday existence and they have also always managed to find new sources of energy when the old source that are easily available have been depleted. However, the depletion of the easily available sources led to humans seeking other sources beneath the soil where they found more consumable material like aged wood and coal, which they developed ways for using and used until demands for energy grew greater and another source of energy was located, this time oil which could utilized much easier than coal. Both coal and oil proved to be more than adequate suppliers of the energy required for all human activities but unfortunately, their use came with a significantly high price, a price that many considered to be far too great as their continued use appeared to be placing significant limitations on human existence. The fear that this realization created caused the human population to once again start the process of finding a newer, cleaner, safer source of energy that could eliminate the what they came to see as an impending crisis and the drive to utilize a cleaner, safer energy led to the vision to utilize a greater portion of the Sun’s energy. This current drive to utilize more of the Sun’s energy, solar energy, requires the conversion of the Sun’s radiation to create electrical energy for use in modern society inclusive of in homes, businesses and industries, however, this desire to utilize more of the Sun’s energy directly is not new as in the recent and more distant past natural solar energy had been extensively utilized for almost every human endeavor from the beginning of human existence through to modern times to help meet all basic human physiological needs inclusive of eating, drinking, heating, cooking, sleeping and washing. Humans have utilized direct solar energy in many productive endeavors inclusive of the production of things to eat, agriculture, water to drink, hydrology, the long term preservation of reaped agricultural crops and animal products, the construction of shelters to protect themselves from the elements, residential abode, and the construction of places for communal gathering, religious facilities, the construction of household and other vessels and daylight heating, all of which have been fundamental to the growth and wellbeing of early human lives and civilizations.

Agriculture. The early development of agriculture created the base for the development and growth of human civilizations as the creation of a regular, consistent source of nutrition that the domesticated crops provided required human stability for the processes involved in clearing and preparing lands, planting, reaping, processing and storing of the excess crops for long-term use. This need to be stable caused by realities of agriculture, caused the human population to plants roots in one location and as they did so they created permanent place of residency, places for storing agricultural goods and places of business which were to later become the center of many villages that were started which consequently grew to become major towns, cities and centers of learning. This essential system of agriculture was and is based on the fundamental principle of photosynthesis whereby all plants (trees, shrubs, grass, fungi and vines) utilize solar energy to grow and to produce fruits, seeds, tuber, grains, vegetables and herbs, all of which became essential elements in the diets of early humans starting in their days as Hunter-Gatherers, as humans found these many products to be tasty, safe, healthy and nutritious to consume. In ancient times the Hunter-Gathers sought and located plant products and consumed those that they had developed a taste for, however, with developments in knowledge humans learnt to domesticate the plants that they usually found by chance and propagated them by planting seeds or portions of an old plant and then allowed the combination of sunlight (solar energy), carbon dioxide, water and soil nutrients to do their work. These developments led to the selection of a wider variety of plants for consumption, the planting of larger areas and the need for the organization of labor to prepare the land, plant the seeds, reap, process and store the resulting crops.

These early humans also learnt over time that they needed to process the grain crops to separate the grains from the rest of the plant on which they had grown and they also learnt that the processing could be made easier if the plant matter was dry and that the required drying could be done by the heat Sun. This need to utilize sunlight, solar energy, after the crops had been reaped extended beyond the need to separate the grains from the plant matter as the early humans also learned that the heat from the sun could also to help them to process the grains to make them suitable for storing as these crops, especially the grains usually contained a very high percentage of water, water that facilitated the early spoilage of the crops. The early spoilage of the grains usually meant that the people would be forced to eat grains that had started to deteriorate or had gone too bad to be eaten and this would mean starvation and death until a new crop could be reaped. The discovery that drying the grains could make a difference in how long the grains could last also mean that fewer people would become sick or starve before the next crop was ready. The need for drying utilizing solar energy as the source to dry the crops grew with the growing population and consequently the need to grow and store more crops. The need to grow and store more crops was even more important in the regions of the world that had short growing seasons and long winters in which no crops could be grown.

Food Preservation. The seasonal changes in the temperate regions of the world usually means that certain food crops can only be grown for short periods during the year and to ensure that there will be sufficient food to last the whole year ways had to be found to prevent the crops reaped from spoiling and food preservation and storage became very critical for the next stage in human growth and development. This need for food preservation caused humans to develop two basic methods of preventing food from spoiling and both of these methods were totally dependent upon solar energy. The first method developed, was utilizing the direct heat from the Sun to dry out the natural water contained in all crops when they are just reaped and this drying out allowed for the reaped crops to last much longer. These grain crops were dried by spreading them out thinly in large open, hard areas or areas that contained very little water and leaving them exposed to direct sunlight to allow the heat of the sun to penetrate and drive off the natural water contained within the crops. The removal of the natural water contained in the grains or other produce prevented the growth of the water dependent bacteria and fungi that are responsible for the deterioration and spoilage of crops, thereby extending the life of the crops. The same drying process was also utilized in the preservation of animal products as it also prevented the growth of water dependent bacteria and fungi that leads to spoilage in flesh.

The other method of food preservation that was developed was also dependent upon the use of solar energy as this second method utilized common edible salt for preserving meats, fish and poultry as the addition