1. Seminar on Satellite power station
Presented by
Chiranjibi Prasad Behera
M.Tech 2nd year(PSE)
28 April 2017
Department of Electrical Engg.

2. Department of Electrical Engg.
Outline
Introduction
Basic concept
Solar power satellite
Microwave power transmission
SPS 2000
Advantage
Major challenge
Conclusion
references
28 April 2017
Department of Electrical Engg.

3. Department of Electrical Engg.
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.
28 April 2017
Department of Electrical Engg.

4. Department of Electrical Engg.
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).
28 April 2017
Department of Electrical Engg.

5. Basic components required
A huge solar collector, typically made of solar cells.
D.C. to Microwave conversion through magnetron.
Transmitting antenna sub array on the satellite, aimed at earth where rectennas are placed.
28 April 2017
Department of Electrical Engg.

6. Department of Electrical Engg.
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.
28 April 2017
Department of Electrical Engg.

7. Department of Electrical Engg.
Magnetron operation
It is a rotating device that can convert the electricity in to microwaves, by radiating the electro magnetic energy at its resonant frequency.
28 April 2017
Department of Electrical Engg.

8. Department of Electrical Engg.
S.P.S.
28 April 2017
Department of Electrical Engg.

9. Microwave power transmission
How the power gets to earth?
28 April 2017
Department of Electrical Engg.

10. Department of Electrical Engg.
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
28 April 2017
Department of Electrical Engg.

11. Department of Electrical Engg.
Rectenna
“An Rectenna 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
28 April 2017
Department of Electrical Engg.

12. Department of Electrical Engg.
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
28 April 2017
Department of Electrical Engg.

13. Department of Electrical Engg.
Wire mesh reflector
28 April 2017
Department of Electrical Engg.

14. Department of Electrical Engg.
Magic carpet
28 April 2017
Department of Electrical Engg.

15. block diagram of a rectenna
The rectenna is composed of an RF antenna, a low-pass filter, and a rectifier. It is a purely passive system and needs no extra power. A low-pass filter is necessary to suppress the microwave radiation that is generated by nonlinearities in the rectifier. Most rectifiers use Schottky diodes. Various rectenna schemes have been proposed and the maximum conversion efficiencies anticipated so far are 91.4% at 2.45 GHz and 82% at 5.8 GHz
28 April 2017
Department of Electrical Engg.

16. Department of Electrical Engg.
Working model of Japanese Space Solar Power Plant SPS2000 in Sagamihara, Japan
28 April 2017
Department of Electrical Engg.

17. Department of Electrical Engg.
Estimation
For the production of 1 GW power at the ground, 14 GW of power has to be produced at space. This requires a solar panel of 10 km2 area. Transmitted antenna of length 2 km. microwave has to be transmitted at a frequency of 2.45 GHz or 5.8GHz. And rectennas of 4km diameter are required to capture the transmitted microwaves.
28 April 2017
Department of Electrical Engg.

18. 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.
28 April 2017
Department of Electrical Engg.

19. Department of Electrical Engg.
Continued…
Environment is not heated because scattering of radiations takes place in space.
5 to 6 GW of electricity can be produced by this station.
If microwave beam carrying power could be beamed uniformly over earth they could power cell phones.
Sending energy from spacecraft to spacecraft and to the dark side of the moon for further investigation
28 April 2017
Department of Electrical Engg.

20. Department of Electrical Engg.
Major challenges
It takes large area in space.
20 to 30 years may be required to complete satellite power station.
Cost of transporting equipment for satellite power station to space is very high.
Microwave power radiation may interfere with communication line.
28 April 2017
Department of Electrical Engg.

21. Department of Electrical Engg.
continue
Effect of microwave transmission on atmosphere, human being, ionosphere have to be investigated and evaluated.
Maintenance of space system is a difficult and expensive task.
For keeping the overall efficiency above 50%, a suitable microwave power device, accurate control of antenna, proper measurement and calibration are required.
28 April 2017
Department of Electrical Engg.

22. Department of Electrical Engg.
conclusion
For Science:
“ what is impossible today, i.e possible tomorrow”.
Although this project 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.
28 April 2017
Department of Electrical Engg.

23. Department of Electrical Engg.
references
(1) R.K. Rajput,’Power plant engineering’, Laksmi Publications(P) Ltd.
(2)Dr. P.S. Bimbhra,’ Power electronics’, Khanna Publishers.
(3)Dr. P.S Bimbhra,’ Electrical machinery’, Khanna Publishers.
(4)MATTHEW N. O. SADIKU ,’Elements of electromagnetic,’ Oxford university press.
(5)second draft by m. shinohara,’ New approach to space based solar power from satellite’,
(6) Micheal E. Thomas, ‘Wireless power transmission for solar power satellite’,
28 April 2017
Department of Electrical Engg.

24. Department of Electrical Engg.
THANK YOU
28 April 2017
Department of Electrical Engg.