04-08-2012, 01:40 PM
Satellite power station
Satellite power.ppt (Size: 986.5 KB / Downloads: 87)
Introduction
The demand for energy worldwide has increasing by 100% or almost doubled in every decade.
The world’s main source of power is still generated by fossil fuels which is limited.
(85% of the total power globally)
Harmful effects of hydrocarbon-based power sources to environment.
Regional political and religious conflicts can disrupt world-wide distribution of fossil fuel.
Power generation using SPS overcomes the above problems to a great extent.
Basic concept
Solar Power Satellites providing a better way of power generation.
Transmission of power to earth via microwaves.
Collection of power by specially developed antennas (rectennas).
Solar cell
These are used to convert solar energy directly in to electricity.
The picture shown in the fig. is a PV-type of solar cell. It has two layer N-type of silicon and P-type of silicon. When a beam of sun light falls on its surface, then it will ionised the atoms and electron and holes are produced. By connecting an external circuit we can get electricity.
From the satellite
Power from the satellite is sent to Earth using a microwave transmitter like:-
Slotted waveguide antenna
Dipole antenna
Micro-strip antenna
The beamed power is received through “rectenna” located at a place on Earth
Rectenna design
Currently there are two different design types being looked at
Wire mesh reflector
Built on a rigid frame above the ground
Visually transparent so that it would not interfere with plant life
Magic carpet
Material pegged to the ground
Advantage of SPS over earth based power station
Ground based solar power station only works during clear days and must have storage for night, how ever satellite solar station illuminated 24 hours.
More intense sun light can be captured due to absence of air in space.
Power can be beamed to location where it is needed so there is no need of a large grid.
A network of low orbit satellite could provide power to almost any point on earth continuously.
There is no air and water pollution.
conclusion
For Science:
“ what is impossible today, i.e possible tomorrow”.
Although this has a lot of scientific, engineering, technological challenges, the realization of such a system is not very far away. By the govt. support, cheaper lunch process, involvement of private sector, the installed SPS can provide a base load clear power system on a global scale.