In this article we will know that how solar energy converts into electrical energy, we will know about the conversion of solar energy into electric energy.
SOLAR POWER PLANT
A solar power plants coverts solar energy into electrical energy. It consists of the following sub- systems.
- Solar energy collection system
- Thermal energy transfer system
- Thermal energy storage system
- Energy conversion system.
Conversion of Solar Energy into elec
A number of designs for the above sub- systems have been proposed. However only two types of solar power plants have been found to be feasible. These are known as Solar Farm or Distributed Collector system (DCS) AND Solar tower or central receiver system. The sub-system for the (DCS) having the following main features and details.
1. Solar energy collection system
The solar energy collection system for a DCS may consist of parabolic or parabolic dish collector.
A parabolic trough collector has an axial parabolic reflector at the focus of which is a heat receiver in the shape of tube. The trough is generally made of glass segments hot mould to shape and silvered on the back face. The segments are provided with a backing surface while may be made of metal of fiber glass or concrete. A number of troughs are combined to form a module. The heat receiver system, for troughs collector, consist of a metal tube inside a glass tube. The inner tube is generally painted black to aid heat absorption. The outer tube minimizes losses. Such a collector result in heat transfer medium temperature in the range of 150%c to 350%c and has an efficiency of about 25%c
The dish of the parabolic dish collector is made of segments of synthetic material (e.g. fiber glass).small mirrored pieces of facets are bonded to the segments with a special adhesive. The receiver system for this collector has the shape of a sphere having a specially coated external. Surface Small diameter pipes run within the wall of the receiver and carry the heat transfer medium. This collector system result in temperature of 200%C 500%C in the heat transfer medium. its very use full for conversion of solar energy into electrical energy.
2. Thermal energy transfer system.
This transfers the heat energy from the receiver to the turbine. Water, sodium, salts gases (air, helium. Hydrogen, ammonia) can be used as heat transfer media.
When the transfer medium is water, steam can be generated directly in the receiver. When the medium is gas, a gas turbine has to be used. When sodium and salts are used for heat transfer, secondary heat transfer circuit is also necessary and the cost is higher. However, when these media are used higher working temperature and pressures can and the heat transfer coefficients are higher.it is first step of conversion of solar energy into electrical energy.
3. Thermal energy storage system.
Solar energy is not available all the time. If a solar power plant is working as an isolated plant and is the only source of supply for an area, some from heat energy storage is necessary. One form of storage can be a pressure vessel storing water and steam at a temperature near the boiling point. When steam is extracted, both temperature and pressure in the vessel decrease causing conversion of water into steam. In this storage system into can run only on part load. The thermal storage system can system can also consist of sodium or molten salt. When this storage system is used, two transfer circuits are necessary. However the turbine can operate at full load from such a storage system. it provide continuity of conversion of solar energy into electrical energy.
4. Energy conversion system.
The energy conversion system converts heat energy to electrical energy. The solar heat from the receiver or storage converts feed water into steam which is fed to turbine. The turbine drives the generator. Steam is condensed in the condenser and water return to the boiler for reuse as feed water .The heat of the cooling water of the condenser may be used for subsidiary purposes. In various image shows the basic element of a distributed collector system solar power plant. in this type solar energy convert into electrical energy.
SOLAR POWER TOWER.
Considerable attention has been given, during the last few years, to solar power tower concept for conversion of solar energy to electrical energy. In this method a central receiver situated at the top of a tower receivers concentrated solar energy reflected from a field of mirrors (or hemostats) which are arranged in some regular manner around the base of a tower. This collection system simulates a very large parabolic on ground. The solar energy collected by the receiver is absorbed by a receiver coolant which gets heated up. The heat of this finally transferred to feed water in a boiler. The feed water gets converted into a steam which drives the turbine. The receiver coolant can be water, liquid sodium, molten, salts or gases like helium or air.
. The complete system consists of a number of sub-systems. The sub-systems are (1) hemostat or collection sub-system (2) receiver/tower sub-system (3) electric power generation sub-system consisting of steam turbine and generator (4) cooling tower sub-system for cooling the water used in condenser for condenser steam (5) master control sub-system for controlling the whole system (not shown in the figure). (6) Storage sub-system. Some form of storage is needed to maintain plant output at a constant level despite solar insulation variations. solar power tower improve efficiency of conversion of solar energy into electrical energy.
Solar power tower technology is about 40 years old. A 10 mw pilot plant was commissioned in 1981 in California (USA). Considerable design and hard hardware expertise exists in USA for using this concept. Many economic, simulation and optimization studies have been undertaken. The results of economic studies are quite encouraging. The environmental problems are minimal and the concept seems to offer lasting solution of energy shortage problem.
hence these are some processes which is use in conversion of solar energy into electrical energy if you will find any incorrect in above article you must comment below in comment box.
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