21-03-2011, 03:01 PM
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BEAMED POWER TRANSMISSION FROM SOLAR POWER SATELLITES
Presentation Outline
History
The concept was introduced in 1968
In 1973 Peter Glaser introduced method of transmitting power from satellite using microwaves to the ground.
Space based solar power
Extraterrestrial level for solar irradiance is 1367W/m^2,whereas total terrestrial solar irradiance is 950W/m^2.
Extraterrestrial solar irradiance is thus 144% of the maximum terrestrial irradiance.
Solar power satellites are placed in geostationary orbit.
SPS consists of a large number of solar cells.
The generated power is beamed to earth using microwaves.
By using sps…
Solar panels are exposed to sunlight 24hrs a day.
Expensive storage facilities are not needed.
There is no weather or atmospheric disturbance.
From the Satellite
Solar power from the satellite is sent to Earth using a microwave transmitter
Received at a “rectenna” located on Earth
Recent developments suggest that power could be sent to Earth using a laser
Block Diagram
Microwaves
Frequency 2.45 GHz microwave beam
Power level is well below international safety standard
Magnetrons
1. Cathode
2. Anode
3. Electrons
4. Resonant cavities
5. Curved path of electrons
6. Microwave
7. waveguide
Microwave vs. Laser Transmission
Microwave
More developed
High efficiency up to 85%
Beams is far below the lethal levels of concentration even for a prolonged exposure
Cause interference with satellite communication industry
Laser
Recently developed solid state lasers allow efficient transfer of power
Range of 10% to 20% efficiency
Conform to limits on eye and skin damage
Phased-array antenna
Transmitting antennas are large active phase array.
Electronically steered by varying the timing or phase.
The antenna must have the ability to match the source impedance and load (atmosphere 377W).
Rectenna
Array of dipole antennas known as rectifying antenna or Rectenna
Diameter = Dr
Rectenna
“An antenna comprising a mesh of dipoles and diodes(schotky) for absorbing microwave energy from a transmitter and converting it into electric power.”
Microwaves are received with about 85% efficiency
Around 5km across (3.1 miles)
95% of the beam will fall on the rectenna.
5,000 MW Receiving Station (Rectenna). This station is about a mile and a half long.
Physical Limitations
The receiving diameter Dr increases with transmitter receiver separation distance S.
Dr increases if transmitter diameter Dt decreases
BEAMED POWER TRANSMISSION FROM SOLAR POWER SATELLITES
Presentation Outline
History
The concept was introduced in 1968
In 1973 Peter Glaser introduced method of transmitting power from satellite using microwaves to the ground.
Space based solar power
Extraterrestrial level for solar irradiance is 1367W/m^2,whereas total terrestrial solar irradiance is 950W/m^2.
Extraterrestrial solar irradiance is thus 144% of the maximum terrestrial irradiance.
Solar power satellites are placed in geostationary orbit.
SPS consists of a large number of solar cells.
The generated power is beamed to earth using microwaves.
By using sps…
Solar panels are exposed to sunlight 24hrs a day.
Expensive storage facilities are not needed.
There is no weather or atmospheric disturbance.
From the Satellite
Solar power from the satellite is sent to Earth using a microwave transmitter
Received at a “rectenna” located on Earth
Recent developments suggest that power could be sent to Earth using a laser
Block Diagram
Microwaves
Frequency 2.45 GHz microwave beam
Power level is well below international safety standard
Magnetrons
1. Cathode
2. Anode
3. Electrons
4. Resonant cavities
5. Curved path of electrons
6. Microwave
7. waveguide
Microwave vs. Laser Transmission
Microwave
More developed
High efficiency up to 85%
Beams is far below the lethal levels of concentration even for a prolonged exposure
Cause interference with satellite communication industry
Laser
Recently developed solid state lasers allow efficient transfer of power
Range of 10% to 20% efficiency
Conform to limits on eye and skin damage
Phased-array antenna
Transmitting antennas are large active phase array.
Electronically steered by varying the timing or phase.
The antenna must have the ability to match the source impedance and load (atmosphere 377W).
Rectenna
Array of dipole antennas known as rectifying antenna or Rectenna
Diameter = Dr
Rectenna
“An antenna comprising a mesh of dipoles and diodes(schotky) for absorbing microwave energy from a transmitter and converting it into electric power.”
Microwaves are received with about 85% efficiency
Around 5km across (3.1 miles)
95% of the beam will fall on the rectenna.
5,000 MW Receiving Station (Rectenna). This station is about a mile and a half long.
Physical Limitations
The receiving diameter Dr increases with transmitter receiver separation distance S.
Dr increases if transmitter diameter Dt decreases
