19-06-2012, 03:57 PM
SPACE BASED SOLAR POWER
SPACE BASED SOLAR POWER.pptx (Size: 490.15 KB / Downloads: 202)
Introduction
Need of using Renewable energy sources
Global warming, environmental fossil reservoirs
Current Solar Power
Space Based Solar power
What is the importance of Space Based solar power?
Sun radiates energy about3.5*10^23 KW in space whereas earth only receives 2*10^14 KW
Satellite (Photovoltaic cells)which is present in the space can receive solar energy for continuously
SBSP is clean ,safe, reliable, and can supply base load to consumers
What are main elements in SBSP?
Space-based solar power essentially consists of three elements:
A means of collecting solar power in space, for example via solar cells
A means of transmitting power to earth, for example via microwave or laser
A means of receiving power on earth, for example via a microwave antenna (rectenna)
Photo Voltaic cells
Photovoltaic cells works on the principle of photovoltaic effect
PV cells which as the name implies (photo meaning "light" and voltaic meaning "electricity”), convert sunlight directly into electricity. A module is a group of cells connected electrically and packaged into a frame ,commonly known as a solar panel)
Photovoltaic cells are made of special materials called semiconductors such as silicon
Basically, when light strikes the cell, a certain portion of it is absorbed within the semiconductor material. This means that the energy of the absorbed light is transferred to the semiconductor. The energy knocks electrons loose, allowing them to flow freely.
ADVANTAGES
There is no air in space, so the collecting surfaces could receive much more intense sunlight, unobstructed by weather.
The full solar irradiation would be available at all times expect when the sun is eclipsed by the earth .Thus about five times energy could be collected, compared with the best terrestrial sites
The power could be directed to any point on the earth’s surface.
The realization of the SPS concept holds great promises for solving energy crisis, No moving parts and no fuel required.
Longer collection period: Orbiting satellites can be exposed to a consistently high degree of solar radiation, generally for 24 hours per day, whereas surface panels can collect for 12 hours per day at most.
DISADVANTAGES
Only about half the power generated by the SSP would be delivered to the grid, once all losses are factored in. These losses are on the same order as modern fossil fuel plants.
The frequency of beamed radiation is planned to be at 2.45 GHz and this frequency is used by communication satellites also.
The entire structure is massive, high cost and require much time for construction.
High power microwave source and high gain antenna can be used to deliver an intense burst of energy to a target and thus used as a weapon
Space debris are a major hazard to large objects in space, and SBSP systems have been singled out as a particularly hazardous activity.
CONCLUSION
The SPS will be a central attraction of space and energy technology in
coming decades.
However, large scale retro directive power transmission has not yet been proven and needs further development.
Technical hurdles will be removed in the coming one or two decades..
It is not a pollutant but more aptly, a man made extension of the naturally generated electromagnetic spectrum that provides heat and light for our sustenance.