Solar energy is radiant light and heat from the sun that is harnessed using a range of everevolving technologies such as solar heating, photovoltaics, solar thermal energy, solar architecture, molten salt power plants and artificial photosynthesis it is an essential source of renewable energy, and its technologies are broadly characterized as either passive solar or active solar depending. For measuring the efficiency of a solar power plant you first need to. This was the headline in the new york times on 4 april 1931. Before the industrial revolution, the main source of energy was wood and biomass, which is a secondary form of solar energy. Imagine solar cells installed in cars to absorb solar energy to replace the traditional use of diesel and gas. It turned out to be a premonition, since, 80 years later and electricity is being supplied to millions of human beings in the world from renewable energies such as solar. In these solar thermal power plants, solar radiation is concentrated at a point to generate steam, with steam a steam turbine connected to an electric generator is activated. Sales flourished, but the industry paid a high price for this brief period of prosperity. The light energy, in the form of photons, supplies sufficient energy to the junction to create a number of electronhole pairs. Gcep solar energy technology assessment summer 2006. Solar energy is the one normally used by autotrophic organisms, ie those that perform photosynthesis, also called vegetable. Photovoltaics and solar energy two activities grades. Covering layers of the material selenium with a thin layer of gold. It can be changed into electrical energy by using energy converters.
A solar thermal collector working on this principle consists of a sun facing surface which transfers part of the energy to a working fluid such as water or air. Conversion of light energy in electrical energy is based on a phenomenon called photovoltaic effect. Solar energy is available in abundance and free of cost all across the globe. Design and construction of a solar water heater based on the thermosyphon principle.
Numerous new topics comparison tables solved and unsolved problems, have been added and changes have been made to cater to the changing. We will begin with a quote from the feynman lectures on physics. Solar power plants are very efficient for providing electricity as they make use of the energy of the sun. Solar panels absorb the suns energy and convert into electricity or thermal energy for space heating. Solar panels working principle, design and their use. Pdf the spectrum of solar energy is quite wide and its intensity varies according to the timing of the day and geographic location. All pv modules contain a number of layers from the lightfacing side to the back. Interest in solar energy surged during oil embargoes in 197374 and 1979.
Solar modules are made of semiconductors that are very similar to those used to create integrated circuits for electronic equipment. Direct gain refers to systems that admit sunlight directly into the space requiring heat. Solar energy is inexhaustible source of energy which. The working principle of a solar cell in this chapter we present a very simple model of a solar cell. This thermodynamic limit lies in between 67% for nonconcentrated sunlight and 86% for fully concentrated sunlight 25. Principle of solar cell about solar energy our solar. Solar power plant main components, working, advantages. It is reported that earth receives energy from the sun, which is 10,000 times more than the total energy demand of the planet 4. This is done using a principle known as the photovoltaic effect.
Humanity has now declared its readiness to accelerate the transition to a lowcarbon economy, conscious of the finite. Solar energy is tenuous, undependable, and expensive beyond practicality. The electric contact at the front, has to be transparent, as otherwise, light would not get into the cell. The electrical energy coming from the combined effort of solar panels is stored in the lithium ion batteries to be supplied at night time, when there is no sunlight. Solar thermal energy an overview sciencedirect topics. The principles of photovoltaics green rhino energy. Various means for garnering energy from the sun are presented, including photovoltaics pv, thin film solar cells, quantum dot cells, concentrating pv and thermal solar power stations, which are more efficient in practical terms. As solar energy is the most abundant energy resource, it is almost guaranteed to be an indispensable part of the energy system. They work on the principle of the photovoltaic effect. Solar energys bleeding edge breakthrough pv research projects. Various means for garnering energy from the sun are presented, including photovoltaics pv, thin film solar cells, quantum dot cells, concentrating pv and thermal. Working principle of solar cell or photovoltaic cell.
All the aspects presented in this chapter will be discussed in greater detail in the following chapters. The working principle of a solar cell tu delft ocw. Solar electric systems use solar cells to convert the suns radiant energy into electricity. When certain materials are exposed to light, they absorb photons and release free. This educational material is brought to you by the u. The requirements for this specific that solar energy for solar thermal power plants is the most promising of the.
International journal of engineering trends and technology. In photovoltaic conversion, sunlight falling onto a solar cell induces an electrical tension. While total photovoltaic energy production is minuscule, it is likely to increase as fossil fuel resources shrink. The revision of this text hallmark text on solar energy has been done keeping in mind the current scenario in solar energy requirements. Fundamental properties of solar cells, principles and varieties of. Compared with other energy conversion paths from solar energy to electricity, pv has a higher overall efficiency. Throughout history, solar energy remained popular until abundant sources of fossil fuel became available. The suns energy, for all practical purposes, is certainly in exhaustible. When certain materials are exposed to light, they absorb photons and release free electrons.
How solar panels work introduction in this lesson, students will learn that sunlight is the underlying component of energy use. Solar energy means energy, heat or electricity is produced directly using the energy radiated from the sun renewable energy to earth. Solar cell working principle is developed in 1883 by charles fritts. Working principle of a solar inverter solar inverter guide. Usually made from glass, though in thinfilm modules this can also be transparent plastic. As a result the book is updated with the energy scenario and the various applications of solar energy being. Design and construction of a solar water heater based on. Principles of thermal collection and storage, 3e sukhatme, s. There is no known exception to this lawit is exact so far as we know.
Finally, students will investigate careers in solar energy and report on the. The total amount of solar energy incident on earth is vastly in excess of the worlds energy requirements and could satisfy all future energy needs if suitably harnessed. Since a solar cell only generates about 12 watts of power, it is necessary to combine them into solar power panels in order to generate more power. Students will examine atoms as the basic building blocks of matter, including electrons, protons, and. Most pressingly, the decline of cheap plentiful crude oil peak oil. At any time the sun on the earth sends 67 watts per square meter.
It will produce new electronhole pairs when light shines on the pn knot of the semiconductor, under the function of electric field in the pn. Working principle of wind energy wind is simply defined as moving air. As solar energy is used in abundance for various purposes, constant efforts are being to improvise the efficiency of solar panels, solar power plants and other systems. When the earth heats up from sunrays it releases wind, this is a balanced reaction meant to cool the earth. The principle of operation of this type of solar radiation is very similar, there are two main applications of solar thermal energy. Renewable energy and sustainability equity and limits fuller solar 2005 anzses conference, dunedin, dec 2005 3 of 7 collector area, the number of wind farms and the area under biomassforenergy cultivation.
This cell had a yield of only 1% and was, therefore, more of a proof of concept. The inverters work by taking in power from a direct current dc source, i. Photovoltaics directly convert solar energy into electricity. There is a fact, or if you wish, a law, governing all natural phenomena that are known to date. Energy as this book is on solar energy, it is good to start the discussion with some general thoughts on energy. But in todays world, the words power and energy are leaned more towards electricity. In order to reduce dependence on fossil fuels, many countries are oriented towards alternative energy sources, especially solar energy.
Principles and varieties of solar energy phys 4400 and. The power is generated in the range of 250 volts to 600 volts. If even a fraction of this could be harvested efficiently, the energy crunch could in principle be averted. Many notions presented in this chapter will be new but nonetheless the general idea of how a solar cell works should be clear.
Among those energy conversion devices are solar photovoltaic pv, thermoelectric, electrochemical and pho toelectrochemical pec cells that have been main. However, even though sunlight striking the earth is abundant, it comes in rather a dilute form. In one hour the earth receives more energy from the sun than the world consume in one year. Passive solar techniques include orienting a building to the sun, selecting materials with favorable thermal mass or lightdispersing properties, and designing spaces that naturally circulate air.
The electric generator is responsible for transforming mechanical energy into electricity. When light reaches the pn junction, the light photons can easily enter in the junction, through very thin ptype layer. Solar cell multicrystalline silicon photovoltaic modules, commonly called solar modules, are the key components used to convert sunlight into electricity. Working principle of silicon solar pv cells photovoltaic material of device converts. The conversion from solar energy to electrical energy is done by using solar pv. Solar power plant have a large number of solar panels connected to each other to get a large voltage output. Working principles of solar and other energy conversion cells. Federal and state tax incentives led to rising sales in the early 80s. An assessment of solar energy conversion technologies and. Students describe ways in which the principles and subject matter of other disciplines.
When semiconductor materials are exposed to light, the some of the photons of light ray are absorbed by the semiconductor crystal which causes a significant number of free electrons in the crystal. The caveat is that even if the entire world electricity budget could be met using solar energy, the remaining 80% of energy which is not used as electricity but thermal power heat still needs to be found in the absence of fossil fuels. As a result the book is updated with the energy scenario and the various applications of solar energy being used today. Solar energy by s p sukhatme pdf download strongwindez. The working principle of solar cells is based on the photoelectric effect. Using the same principle, cell phones can also be charged by solar energy. Solar energy, radiation from the sun capable of producing heat, causing chemical reactions, or generating electricity. In fact, calculations based on the worlds projected energy consumption by 2030 suggest that global energy demands would be fulfilled by solar panels operating at 20 percent efficiency and covering only about 496,805 square km 191,817 square miles of earths surface. Light photon energy electric energy silicon solar photovoltaic cells a device made of semiconductor materials that produce electricity under light a pn junction is created in silicon by a doping process. Fundamental properties of solar cells, principles and.
Solar cell working principle explain working of solar. To maintain that renewable energy is able to meet any future demand, no matter how large, is an abandonment of the futurity principle. This, in brief, is a principle of thermal conversion. The earth receives solar energy in the form of light and heat. This heat energy is let to the boiler with a feedback.