Space based solar power generation

1. SPACE SOLAR POWER
MUHAMMED NIHAD P
20042451

2. CONTENTS
1. INTRODUCTION
2.TYPES OF ENERGY
3. DRAWBACKS OF CONVENTIONAL ENERGRY
SOURCES
4.WHY SPS
5. SPS THE BACKGROUND
6. SPS-GENERAL IDEA
7. WIRELESS POWER TRANSMISSION
8. MICROWAVE POWER TRANSMISSION IN SPS

3. CONTENTS
A) TRANSMITTER
B) BEAM CONTROL
C) RECTENNA
9. ADVANTAGES
10. DISADVANTAGES
11. CONCLUSION

4. INTRODUCTION
1. The new millennium has introduced
increased pressure for finding new renewable
energy sources
2. Building a power station in space to transmit
electricity to Earth by way of radio waves-the
Solar Power Satellites.
3. Microwave Wireless Power Transmission
SPS is a clean, large-scale, stable electric power
source

5. TYPES OF ENERGY
There are mainly two types of ENERGY. I.e,
1. CONVENTIONAL ENERGY
2. NON CONVENTIONAL ENERGRY

6. DRAWBACKS OF CONVENTIONAL
ENERGRY SOURCES
A) It Causes Pollution
B) Non Renewable
C) High Cost
D) High Maintanence

7. WHY SPS
• Increasing global energy demand
• Limitation of renewable energy sources
• Environmental problems due to fossil fuels.
• Overcome day & night effect and other factors such
as clouds.
• Overcome energy crisis.

8. SPS THE BACKGROUND
• Peter Glaser invented the concept of a large SPS.
• The U.S Department of Energy (DOE) and the
National Aeronautics and Space Administration
(NASA) examined the SPS concept extensively
during the late 1970s.
• Fresh look Study, SSP Concept Definition Study.
• SSP Exploratory and Research Technology

9. SPS- GENERAL IDEA
• It is located in the geosynchronous orbit.
• Comparison between ordinary satellite.
• Its operation.
• About structure.
• Comparison between terrestrial station

10. WIRELESS POWER TRANSMISSION

11. WIRELESS POWER TRANSMISSION
• The 50Hz ac power tapped from grid line is stepped
down to suitable voltage level for rectification in to dc.
• Then it is supplied to oscillator fed magnetron.
• Magnetron consist of electrons supplied by cathode
which are collected by positively charged anode.
• The electrons are forced to move in a circular path by a
high power permanent magnet.
• Electromagnetic radiation in microwave range is
generated

12. MICROWAVE POWER
TRANSMISSION IN SPS
• The conversion of direct power to microwave
power
• The formation and control of microwave beam
• The collection of the microwave energy and its
conversion into electrical energy at the earth's
surface.
• The key microwave components in a WPT system
are the transmitter, beam control and the receiving
antenna called RECTENNA

13. A) TRANSMITTER
• The key requirement of a transmitter is its ability to
convert dc power to RF power efficiently and
radiate the power to a controlled manner with low
loss.
• The transmitter's efficiency drives the end-to-end
efficiency as well as thermal management system.
• The main components of a transmitter include dc-
to RF converter and transmitting antenna.
• The main dc-RF converters are klystrons

14. KLYSTRON TRANSMITTER
• The tube body and solenoid operate at 300°C and
the collector operates at 500°C.
• The overall efficiency is 83%.
• The microwave power density at the transmitting
array will be 1 kW/m² for a typical 1 GW SPS with a
transmitting antenna aperture of 1 km diameter.
• If we use 2.45 GHz for MPT, the number of antenna
elements per square meter is on the order of 100.

15. KLYSTRON TRANSMITTER

16. KLYSTRON

17. B) BEAM CONTROL
• A key system and safety aspect of WPT in its ability
to control the power beam.
• Retro directive beam control systems have been
the preferred method of achieving accurate beam
pointing.
• A coded pilot signal is emitted from the rectenna
towards the SPS transmitter to provide a phase
reference for forming and pointing the power
beams

18. RETRO DIRECTIVE BEAM CONTROL

19. C) RECTENNA
• RECTENNA is the microwave to dc converting device.
• ❖ It is mainly composed of a receiving antenna and a
rectifying circuit.
• Fig. shows schematic of RECTENNA. It consists of a receiving
antenna, an input low pass filter, a rectifying circuit and an
output smoothing filter.
• In RECTENNA arrays, the diode is the most critical
component to achieve higher efficiencies because it is the
main source of loss.
• * Diode cut off frequency is given by ƒ=1/ [2πRsCj], where f
is the cut off frequency, Rs is the diode series resistance, Cj
is the zero-bias junction capacitance.

20. BLOCK DIAGRAM OF RECTENNA

21. ADVANTAGES
• The power could be directed to any point on the earth's
surface.
• The power density would be uninterrupted by
darkness, clouds, or precipitation, which are the
problems encountered with earth based solar arrays.
• The realization of the SPS concept holds great promises
for solving energy crisis
• No moving parts.
• No fuel required.
• No waste product.

22. DISADVANTAGES
• The main draw back of solar energy transfer from orbit is the
storage of electricity during off peak demand hours.
• 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.
• Radiation hazards associated with the system.
• Risks involved with malfunction.
• 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

25. 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.
Another important of technological area development will be the
reduction of the size and weight of individual elements in the space
section of SPS. Large-scale transportation and robotics for the
construction of large-scale structures in space include the other major
fields of technologies requiring further developments. Technical hurdles
will be removed in the coming one or two decades. Finally, we look
forward universal acceptance of the premise the to electromagnetic
energy is a tool to improve the quality of life for mankind. 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. From this view point, the SPS is merely a down
frequency converter from the visible spectrum to microwaves.