05-12-2012, 11:45 AM
SOLAR TOWER TECHNOLOGY
SOLAR TOWER.ppt (Size: 726 KB / Downloads: 109)
INTRODUCTION
RENEWABLE ENERGY is from an energy resource that is replaced rapidly by a natural process such as power generated from the sun or from the wind.
Solar Mission
SOLARMISSION aims to be one of the world’s leading producers of clean, green renewable energy within five years.
Solar Mission is committed to providing profitable, large-scale renewable energy generation power stations for the United States and the world’s electricity markets.
Our objective is to lead the renewable energy market with innovative technologies that do not consume fuel sources or produce green house gas emissions. that is, with no detrimental effects on the environment from large-scale electricity production.
The Solar Tower project will change the world’s energy markets forever, and possibly, reduce the effects of global warming.
History of Solar Tower
One of the earliest description of solar chimney power station was written in 1931 by German author Hans Günter.
More recently Schalaic,Bergerman and Partner,under the direction of German engineer Prof. Dr.Jorg Schalaic,built a small scale working model of a solar chimney in 1982 in Manzanares(Spain),which was funded by German Government.
This power plant operated successfully for approx. 8 years and was decommissioned in 1989.The chimney had a diameter of 10 meters and height of 195 mt,with a collection area of 46,000 m2 obtaining a maximum power output of 50kw.
During operation,optimisation data was collected on a second-by-second basis.This data has been licensed to Enviromission and SolarMission Technologies who planned to develop the concept under the brand name “Solar Tower”
Solar Tower Technology
Solar tower is not simply solar energy.
Solar Tower technology is created when the sun’s radiation is used to heat a large body of air,which is then forced by the laws of physics(hot air rises) to move as a hot wind through large turbines to generate electricity.
A solar thermal power station using solar tower technology will create the conditions to cause hot wind to flow continuously through its turbines to generate electricity.
EVACUATED TUBE COLLECTOR :
The collector consists of rows of parallel transparent glass tubes, each of which contains an absorber covered with selective coating.
In the evacuated tube collector,sunlight enters through the outer glass tube and strikes the absorber,where the energy is convertd to heat.The heat is transferred to the liquid flowing through the absorber.
Air is evacuated from the space between the two tubes, forming a vaccum. This reduces conductive and convective heat loss from the interior of the tube.
CONCENTRATING COLLECTOR :
Concentrating collectors use curved mirrors to concentrate sunlight on the receiver. It uses a focusing device, an absorber/receiver provided with or without transparent cover and a tracking device for continuously following the sun.
There are 4 basic types of concentrating collectors
1. Parabolic trough collectors
2. Parabolic dish system
3. Power Tower System
4. Stationary concentrating collectors
PARABOLIC DISH SYSTEM
A parabolic dish collector is similar in appearance to a large satellite dish, but has mirror-like reflectors and an absorber at the focal point.It uses a dual axis sun tracker. This system uses a computer to track the sun and concentrate the sun’s rays onto a receiver located at the focal point in front of the dish.
STATIONARY CONCENTRATING SOLAR COLLECTORS
Stationary concentrating collectors use compound parabolic reflectors and flat reflectors for directing solar energy to an absorber through a wide acceptance angle. The wide acceptance angle for these reflectors eliminates the need for a sun tracker.
Feasibility in our country
Indian government decision only to import coal makes the thermal power a lot more expensive.
For the present boom in our economy the government has to solve the power with long term investments.
The Thar desert in Rajastan has to be utilized with such projects.