17-11-2012, 11:22 AM
WIRELESS TECHNOLOGY
solar power satellite.pptx (Size: 705.17 KB / Downloads: 23)
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.
Solar Power Satellites providing a better way of power generation
Solar Power Satellite
Solar Power Satellite or SPS, is a proposed satellite built in geostationary earth orbit (or) low earth orbit in that by using a microwave power transmission a very large antenna in Earth where it can be converted into the electricity.
Basic Concept
Collecting a solar energy from solar by using a photovaltic cells.
Transmission of power to earth via microwaves
Receiving a collection of power is by specially developed antennas (rectennas)
Basic Components
Solar Collector Panel.
i)Photovoltaic cell
ii)Solar dynamic
Transmitting and Receiveing antenna sub array on the satellite, aimed at earth.
D.C. to Microwave conversion through magnetron.
Specifications
Satellite antenna must be between 1 and 1.5 kilometers in diameter and the ground rectenna around 14 kilometers by 10 kilometers .
Collector area must be between 50 (19 sq miles) and 150 square kilometers (57 sq miles)
Possible power generation of 5 to 10 Gigawatts
“If the largest conceivable space power station were built and operated 24 hours a day all year round, it could produce the equivalent output of ten 1 million kilowatt-class nuclear power stations.”
Microwave Conversion
Power from the satellite is sent to Earth using a microwave transmitter
The beamed power is received through “rectenna” located at a place on Earth
Rectenna
“An antenna comprising a mesh of dipoles and diodes for absorbing microwave energy from a transmitter and converting it by rectification into D.C. power.”
Microwaves are received with about 85% efficiency
95% of the beam will fall on the rectenna
Rectification
The conversion from A.C. to D.C. by means of rectifying device.
Types of rectification schemes.
-half wave
-full wave
The expected overall rectification efficiency,
ηc=dc output power/rf incident power
The obtained conversion efficiency due to mismatch,
ηc=dc output power/
(rf incident power-rf reflected power)
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
Advantages
Power output is very high.
Microwave does not affect the birds
Microwave beam can be directed to all directions by using rectenna where it is desired.
Power production can be done for 24hours.
Power loss is less.
No air,nuclear and water pollution.
It doesn’t have a seasonal effect.
Conclusion
To overcome our country power production demand we have go for solar energy as renewable energy source.
Benefits of this satellite is very high.
Many power production problems can be solved by launching this satellite in our country.