In this seminar topic,I included all the things related SPS system & how microwave power transmission can done through magetron,retro directive beam controlling scheme & all.I also mentioned the design of optical rectenna & economic evolution of the topic.

1. SEMINAR
PRESENTATION ON:
SOLAR POWER SATELLITE & MICROWAVE
POWER TRANSMISSION.
PRESENTED BY:
BHAVISHA PATEL
M.TECH-EE

2. OVERVIEW
HISTORY
SPS SYSTEM
&
MICROWAVE
POWER
TRANSMISSION
BLOCK
DIAGRAM
COMPONENT
&
OPERATION
ADVANTAGES
&
DISADVANTAG
ES
APPLICATIONS
OF WPT
CONCLUSION
&
FUTURE SCOPE
REFERENCES

3. HISTORY
1856-
1943
• Nikola tesla gave the idea of WPT, hence he is called as “FATHER OF WIRELESS”
1958
• First US satellite that used solar power. Development of photovoltaic cell in 1940-50’s.
1964
• W. C. Brown demonstrated a rectennas which could convert microwave power to electricity.
1968
• Idea for solar power satellite proposed by peter glaser.
1983
• The first MPT experiment in space was conducted in japan.

6. Figure:1) Evaluated power flow diagram

7. What is SPS?
 Solar Power Satellites would be located in the geosynchronous orbit. It receives power from
space and converts it into electricity.
 The solar energy collected by an SPS would be converted into electricity, then into
microwaves. The microwaves would be beamed to the Earth’s surface, where they would be
received and converted back into electricity by a large array of devices known as rectifying
antenna or rectennas.
 Each SPS would have been massive; measuring 10.5 km long and 5.3km wide or with an
average area of 56 sq. km. The surface of each satellite Would have been covered with 400
million solar cells.

8. Step:1)Solar to electrical energy

9. Step:2) Generation and transmission of
microwave.
Primary
component of
MPT
Microwave
generator
Transmitting
antenna
Beam
control
Rectenna

10. Microwave Generator
 Microwave generator are used to produce the microwaves.
 Microwave transmitting device are classified as:
1)microwave vaccum tube(magnetron,klystron etc..)
2)semiconductor microwave transmitters(GaAS).
 Magnetron is widely used for experimentation of WPT.

11. Magnetron
 Magnetron is a high powered
vacuum tube device that
generates microwaves owing to
the motion of clouds of electrons
in a crossed electric and magnetic
fields.
 Magnetron originally developed
in 1916 as an alternative to grid
control in vacuum tubes.

12. Construction and working
 1)cathode
 2)anode
 3)electrons
 4) cavities or resonant cavities.
 5) curved path
 6) microwave radiation
 7) waveguide

13. waveguide
 Waves are confined in a waveguide because of total reflection from its inner surface.
 Magnetrons also have its internal waveguide but for desired wave’s area, an external
waveguide is required.
 Waveguides are of different types depending upon their applications.

14. Microwave Power Transmission
 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.

16. MPT Based on Retro-reflective Beam forming
 The MPT is that power can be transmitted to moving targets using microwave beam forming
techniques.
 In this manner, it is easy to change the beam direction to accommodate moving targets using
phased array techniques without any motion of the transmitting antenna. This suggests that
wireless microwave power can be transmitted to/from moving targets with high-beam efficiency.
 WHY?
(1) minimizing power loss due to microwave propagation,
(2) preventing humans and other electrical systems from exposure
to excessive microwave radiation, and
(3) reconfiguring wireless power transmission in reaction to
environmental changes (such as physical movements of portable
devices) in real time.

17. Retro-reflective beam-forming scheme
Fig: Depiction of wireless power transmission based on retro-reflective beam-
forming.

18. Timing sequence in the retro-reflective beam-
forming scheme.

19. System block diagram of the retro-reflective beam-
forming scheme

20. Rectenna
 A rectenna is a rectifying antenna — a special type of receiving antenna that is used for
converting electromagnetic energy into direct current (DC) electricity. They are used in
wireless power transmission systems that transmit power by radio waves.

21. Types of
rectenna
Radio frequency
rectenna
Optical rectenna
Carbon
nanotube optical
rectenna

22. Optical rectenna
 It is scaled down to the proportions used in nanotechnology, can be used to convert light directly
into electricity. This type of device is called an optical rectenna or nantenna.
 With the use of atomic layer deposition it has been suggested that conversion efficiencies of
solar energy to electricity higher than 70% could eventually be achieved.
 The Challenges to successful nantenna technology include fabricating an antenna small enough
to couple optical wavelengths, and creating an ultrafast diode capable of rectifying the high
frequency oscillations.

23. construction and working
• In 2015, researchers fabricated an optical
rectenna using arrays of 2 million multiwall
carbon nanotubes (MWCNT) per cm2 coupled
to nano scale rectifying diodes.
• The MWCNT, which act as optical antennae due
to their favorably small dimensions, are coated
in aluminum oxide and capped with a metallic
top layer.
Fig: Optical Rectenna

24. Fig_a): Schematic diagram of the rectenna design(Top view)

25. Fig: Schematic diagram of the rectenna design(b)side view,(c)3D
view.

26. Economic Evaluation of Solar Power Satellite
System
 An economic evaluation comparison have been innovated between solar power satellite and the
other renewable resources by means of net present value.
 Framework for calculation of net present value is described and the results are shown as two
statements of present and future.
 There are some parameters that are affecting in space solar power system cost such as cost of
launch, cost of conversion element, solar concentration factor, space segment conversion
efficiencies (PV, DC-RF, antenna), area-specific mass (PV, sandwich module, reflectors),
mass of space segment elements(energy conversion, structures, attitude control
system,propellants), transmit antenna diameter, transmission frequency, orbital assembly
costs, orbital altitude, satellite constellation size, in-space transportation costs, space segment
operation and maintenance costs, launch vehicle mass and volume capacities (low earth
orbit, geosynchronous orbit, geosynchronous transfer orbit), launch segment costs, launch
rate, system deployment time.

27. capacity factor of each renewable source (%)
 Where Cins is the initial cost of installing solar power
satellite system.
 Annual cash flow (ACF) is defined based on
capacity factor ( Fc), energy price (π ), fixed cost ( Cf ),
variable cost (Cv) and nominal power ( Pn ).
 d is discount rate and yp is project lifetime.

28. Economic evaluation comparison of renewable
resources in the present & future
• Future statement appears to be competitive with current renewable energy alternatives.
Given the advancement of technology and reduce of SPS installation cost in the future,
from an economic point of view, NPV increased form a negative value to a good
positive value. The IRR value is about 40%, which indicates high profitability of the
project.

29. Fig: 5000 MW receiving station in Japan.

30. Advantages
1)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.
2) The power could be directed to any point on the earth’s surface.
3) The zero gravity and high vacuum condition in space would allow much lighter, low
maintenance structures and collectors.
4) The power density would be uninterrupted by darkness, clouds, or precipitation, which are the
problems encountered with earth based solar arrays.
5) The realization of the SPS concept holds great promises for solving energy crisis.
6) No moving parts.
7) No Fuel Required.
8) No Waste Product.

31. Disadvantages
1) The entire structure is massive.
2) High cost and requires much time for construction.
3)Radiation hazards associated with the system.
4) Risks involved with malfunction.
5) 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.

32. Application of WPT(Wireless Power Transmission)
 Moving robots & fuel free rockets, battery charging, car charging, remote control,
game controller, fuel free electric vehicles etc.
 It is used for sensors, computers, laptop charging, television & many more.

33. Conclusion and Future Scope
 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 area of technological 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.
 The 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.

34. References
[1] Hanley, Gerald Michael. Satellite power systems (SPS) concept definition study. National
Aeronautics and Space Administration,Scientific and Technical Information Branch, 1980.
[2] H. P. Davis, Space-Based Solar Power, An Update, Solar High Study Group, SolarHigh.Org,
August 23rd, 2012.
[3]https://www.mwrf.com/systems/rectenna-serves-245-ghz-wireless-power-transmission
[4]https://www.researchgate.net/publication/224153869_A_245-
GHz_low_cost_and_efficient_rectenna
[5]https://core.ac.uk/download/pdf/144146820.pdf
[6]“Microwave Power Transmission Based on Retro-reflective Beamforming”By Xin Wang and
Mingyu Lu,Submitted: October 15th 2015,Reviewed: March 4th 2016Published: June 29th 2016
[7]http://www.kenkai.jaxa.jp/eng/research/ssps/ssps-mssps.html