The theory of solar cells explains the process by which light energy in photons is converted into electric current when the photons strike a suitable semiconductor device. Solar energy is a major renewable energy source with the potential to meet several challenges we face as humankind. An overview of solar cell technology stanford university. Oct 23, 2018 photovoltaic pv panels are comprised of individual cells known as solar cells. Nov 19, 2014 solar cells, the building blocks of solar arrays, are simple twowire diodes packaged and configured to produce electrical current when exposed to electromagnetic radiation of suitable frequency. Performance metrics such as efficiency, shortcircuit current, fill factor, and open. Introduction to photovoltaic solar energy miro zeman delft university of technology 1.
Solar energy plants are found where there is a high concentration of unobstructed sunlight. After beginning with a series of pages of introductory physics to bring nonscientists up to speed, this section will delve into the fundamentals of solar physics in a way that can be understood by those who are not experienced in scientific studies. Photovoltaic pv panels are comprised of individual cells known as solar cells. Photovoltaic solar energy conversion provides an introduction to the fundamental physical principles of solar cells. Today it is a rapidly growing and increasingly important renewable alternative to conventional fossil fuel electricity generation, but compared to other electricity generating technologies, it is a relative newcomer, with the first practical photovoltaic devices demonstrated in the 1950s. Perovskite solar cell psc materials a perovskite solar cell, that was first reported by. It stores and transports energy produced from other resources fossil fuels, water, and biomass. Many different solar cell technologies are being developed, for various applications rooftops, solar power plants, satellites, backpacks or clothing, etc. Each materials pn junction will produce electric current in response to different wavelengths of light. On the basis of the cost problem, we have developed new solar cells based on organic and organicinorganic hybrid materials. The photovoltaic solar energy plant scheduled for completion in 2011 at deming, new mexico, will be 300 megawatts.
We give the upper limit to the solar cell e ciency. Three generations of solar cells, crystalline silicon solar cells, thin lm solar cells and photoelectrochemical cells, are described by means of their. The overwhelming majority of solar cells are fabricated from silicon with increasing efficiency and lowering cost as the materials range from amorphous noncrystalline to polycrystalline to. When charged by the sun, this basic unit generates a dc photovoltage of 0.
The dc signals are fed into an inverter, which converts the dc into gridcompatible ac power which is what you use in your home. The oldest solar cell technology and still the most popular and efficient are solar cells made from thin wafers of silicon. The working principle of a solar cell in this chapter we present a very simple model of a solar cell. Semiconductors typically use the cgs centimeter, gram, second unit system. A large majority of solar cells are made from silicon. First there are panels, which collect the sunlight and turn it into electricity.
This implies the cell must be flat, with a broad side situated as close to perpendicular as possible to the incoming radiation. This course gives you an introduction to the fundamentals of solar power as it applies to solar panel system installations. When photon hits solar cell, its energy breaks apart electronhole pairs. The solar panel, the first component of a electric solar energy system, is a collection of individual silicon cells that generate electricity from sunlight. But solar cell fuel is delivered for free all over the world.
Sep 01, 2011 this introduction to solar cells covers the basics of pn junctions, optical absorption, and iv characteristics. Fundamental properties of solar cells, principles and varieties of. The use of multiple semiconducting materials allows the absorbance of a broader range of wavelengths, improving the cells sunlight to electrical energy conversion efficiency. Since the voltage is too small for most applications, to produce a useful voltage, the cells are connected in series into. Solar photovoltaic technology basics department of energy. When activated with energy from sunlight, electrons move across the cell into the electrical circuit connected to the solar panel. Pv systems vary in size, depending upon the application. Solar cell basics lab ideal research is our business. An overview of solar cell technology mike mcgehee materials science and engineering global climate and energy projectglobal climate and energy project center for advanced molecular photovoltaics precourt institute stanford university konarka nanosolar john benner provided the slides with the nrel logo. Solar panels generate free power from the sun by converting sunlight to electricity with no moving parts, zero emissions, and no maintenance. Cell module pv terminology array cell module or panel courtesy of doenrel.
This video is intended for beginners so obviously there is a. Part ii aims to cover all the physical fundamentals that are required for understanding solar cells in general and the different technologies in particular. Solar cells and photodetectors are devices that convert an optical input into current. The theoretical studies are of practical use because they predict the fundamental limits of a solar cell, and give guidance on the phenomena that contribute to losses and. This seminar is a short overview of current photovoltaics. Each solar cell generates a small amount of electricity. Multijunction mj solar cells are solar cells with multiple pn junctions made of different semiconductor materials. A photon of light energy is absorbed by the silicon semiconductor and if it has sufficient energy it forms an electronhole pair or exciton. A volt is the unit of electromotive force that will force a current of one ampere through a resistance of one ohm.
Light actually penetrates into the cell, it doesnt just bounce off the surface. Application of pn junctions within solar cells is discussed. See the energy profiles page for more general information. It aims to promote the expansion of solar photovoltaics from relatively small and specialized use to a largescale contribution to energy supply. Pdf solar cells are a promising and potentially important technology and are the future of sustainable energy for the human civilization. One cell produces very little power on its own, but when strung together in a series, the cells work together to create substantially more power. When photons strike a pv cell, they may be reflected or absorbed transmitted through the cell. When light reaches the pn junction, the light photons can easily enter in the junction, through very thin ptype layer. This is intended to be a quick explanation of the basics of direct solar conversion the photovoltaic effect. The solar star pv power station produces 579 megawatts of electricity, while the topaz solar farm and desert sunlight solar farm each produce 550 megawatts. All waves have a certain distance between peaks called the wavelength figure 11. A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.
Few facts of solar energy are explained below a perovskite structured compound is present in perovskite solar cell. Shading one cell will essentially turn off all the cells in its group. The solar cell is the basic building block of solar photovoltaics. The readeris told why pv cells work, and how theyare made. The basic components of a home solar power system dummies.
All the aspects presented in this chapter will be discussed in greater detail in the following chapters. I have done some research on how to make these solar cells and found the solution on how to make them work. Solar cells convert the suns energy into electricity, similar to the way plants convert the suns energy into food through photosynthesis. Solar photovoltaic cell basics department of energy.
As such solar cells belong to the family of of bipolar junction devices, which also includes diodes and bipolar junction transistors bjts. Solar cells, also called photovoltaic cells, convert sunlight directly into electricity. So the amount of solar energy that reaches any given location varies by latitude, time of year, time of day, and local weather. Many of the topics that are discussed in this book are also covered in the massive open online course mooc on solar energy delftx, et. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to. The solar cell traps all the electrons released by the silicon and pushes them in one direction, which creates an electric current. In addition the book also covers other forms of solar energy, in particular solar thermal applications and solar fuels.
Various switch boxes are included for safety reasons, and. Now, when this two type of silicon interact, an electric field forms at the junction which prevents more electrons to move to pside. A solar cell is an example of a photovoltaic device, i. You also have to find some type of glass or fiberglass to cover the dimensions of the cells. You will learn to compare solar energy to other energy. Pdf this text is addressed to upper level graduate students with background in solid state physics and to scientists and engineers involved in solar.
A solar cell is a solidstate electrical device pn junction that converts the energy of light directly into electricity dc using the photovoltaic effect. The course is a tour through the fundamental disciplines including solar cell history, why we need solar energy, how solar cells produce power, and how they work. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Since the voltage is too small for most applications, to produce a. Many notions presented in this chapter will be new but nonetheless the general idea of how a solar cell works should be clear. A perovskite structured compound is a hybrid organicinorganic lead or tin halidebased material and also has the active layer for harvesting the light. Voltage voltage v is a measure of the amount of pressure, or electromotive force, applied to electrons to make them move. Fundamental properties of solar cells, principles and. Solar cell, also called photovoltaic cell, any device that directly converts the energy of light into electrical energy through the photovoltaic effect. To take advantages of solar energy, the variety of technologies is used to covert solar energy to. When you connect many solar cells together, a solar panel is created that creates a substantial amount of electricity. The other part of a solar cell is doped with the element boron with 3 electrons in its outer shellto become ptype silicon. Home solar photovoltaic cell basics when light shines on a photovoltaic pv cell, it may be reflected, absorbed, or pass right through it. Learn solar energy basics from the state university of new york.
This power source is increasing in popularity because of its versatility and many benefits to people and the environment. Jun 17, 2014 in this video, i will show you in laymans terms how a solar panel system works and how to set one up in 2 different types of systems. Photovoltaics often shortened as pv gets its name from the process of converting light photons to electricity voltage, which is called the photovoltaic effect. The working principle of a solar cell tu delft ocw. John benner provided the slides with the nrel logo. The light energy, in the form of photons, supplies sufficient energy to the junction to create a number of electronhole pairs. Solar energy is the ultimate source of energy, which is naturally replenished in a short period of time, for this reason it is called renewable energy or sustainable energy source. Commonly known as solar cells, individual pv cells are electricityproducing devices made of different semiconductor materials. To take advantages of solar energy, the variety of technologies is used to covert solar energy to heat and electricity.
Solar electric system design, operation and installation. The use of solar power for home, office, barn, etc. The cells efficiency was less than 1%, meaning than less than 1% of the light energy was converted into electricity. However, the thickness of a solar cell will be measured in microns.
Solar cells work by using the suns energy to enable electrons in. Solar pool heating hot water for pools solar water heating swh or. Solar electric system design, operation and installation an overview for builders in the pacific northwest. So what i did was measure these 10 solar cells and i was able to get a.
Charles fritts produces the worlds first solar cell, a device that converts sunlight into electricity, using selenium and gold. All the aspects presented in this chapter will be discussed in greater detail in the. Basics of photovoltaic pv systems for gridtied applications pacific energy. After discussing some basics from electrodynamics in chapter 4 and solar radiation in chapter 5, we spend several. Rigid solar panels cell are usually made up of either monocrystalline or. An overview of solar cell technology mike mcgehee materials science and engineering global climate and energy projectglobal climate and energy project center for advanced molecular photovoltaics precourt institute stanford university konarka nanosolar. Introduction to solar cells horizon energy curriculum. Commercial production of csi modules began in 1963 when sharp corporation of japan started producing commercial. Photovoltaics is the process of converting sunlight directly into electricity using solar cells.
Whether you are looking for general insight in this green technology or your ambition is to pursue a career in solar, introduction to solar cells is an excellent starting point. The process of conversion first requires a material which absorbs the solar energy photon, and then raises an electron to a higher energy state, and then the flow of this highenergy electron to an external circuit. For this reason it is useful to characterize light radiation by parameters associated with waves. The pv cell is composed of semiconductor material, which combines some properties of metals and some properties of insulators. The silicon wafer has an electron rich n layer and an electron poor p or hole layer. Solar intertie photovoltaic pv systems are not particularly complex. In part one, solar cell fundamentals, chapter 1 gives an overview of photovoltaic. Solar cells are used on spaceships like the international space station pictured below, but are also used on earth in places that get lots of sunlight throughout the year. A hydrogenpowered internal combustion engine h2ice passenger bus produced by ford motor company is used on. San francisco, ca 94103 stockton, ca 95204 courtesy of doenrel.
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