MANAGEMENT AND OPTIMIZATION OF SOLAR
POWER CONVERSION TO SUPPLEMENT
TERRESTRIAL POWER SYSTEMS.
BY
Dr. P.S. Tiwari,
Group Director &
Faculty Mentor,
TIT Group of
Institutions, Bhopal.
&
S.R. Awasthi,
Consultant,
CECL, Bhopal
CONVENTIONAL RESOURCES
• FOSSIL FUELS
• HYDRO RESOURCES
• NUCLEAR RESOURCES USING
FISSION
ENVIRONMENTAL ASPECTS
OF ENERGY
• TRADE-OFF BETWEEN ENERGY AND
ENVIRONMENT
• ECOLOGICAL UNBALANCE
• GLOBAL WARMING
• RADIATION HAZARDS
NON-CONVENTIONAL RESOURCES
•
•
•
•
•
•
•
SOLAR ENERGY
WIND ENERGY
BIOMASS ENERGY
OCEAN WAVE ENERGY
OCEAN THERMAL ENERGY CONVERSION
GEOTHERMAL ENERGY
OCEAN TIDAL ENERGY
AND
• NUCLEAR FUSION
LIMITATIONS OF SOLAR ELECTRIC POWER
GENERATION INSTALLATIONS ON EARTH
• Effects of day/night cycles
• Shadowing due to clouds, fog, snow,
precipitation etc.
• Weather effects
• Reduced solar-radiation intensity
• Overall variable and discontinuous power
output
LIMITATIONS OF SOLAR ELECTRIC POWER
GENERATION INSTALLATIONS ON EARTH
Contd….
HENCE:
SOLAR POWER SATELLITE
CONCEIVED
SALIENT ADVANTAGES OF SPS
• More intense (about eight times on
average) solar radiation available
• Unaffected by weather, clouds etc.
• SPS illuminated almost all the time (except
eclipse periods). Hence expensive
storage not required
• Lack of gravity simplifies structure
• Waste heat re-radiated back into space,
instead of warming the biosphere.
SOLAR TO ELECTRIC CONVERSION
• THERMAL ELECTRIC CONVERSION
• SOLAR DYNAMIC CONVERSION
• DIRECT CONVERSION THROUGH
PHOTOVOLTAICS
SOLAR TO ELECTRIC CONVERSION
Contd….
POINTS FOR CHOICE:
• Energy conversion efficiency
• Cost effectiveness
• Material and system transportation
convenience
• Technology status
• Specific feasibility problems
MAIN PARAMETERS FOR CONSIDERATION OF
PHOTOVOLTAIC POWER GENERATION ON SPS
•
•
•
•
•
Energy conversion efficiency
Life-expectancy
Tolerance to space-radiation environment
Power-production capacity per unit area
Production cost including material cost and
processing cost
MAIN PARAMETERS FOR CONSIDERATION OF
PHOTOVOLTAIC POWER GENERATION ON SPS
Contd…..
• Amenability to mass production
• Consideration for optimized mass
• Overall bulk and portability
BRIEF HISTORICAL MILESTONES
• 1899-1900 NIKOLA TESLA Proposed use
of radio waves power transmission
• 1930’s Use of microwaves proposed for
power transmission
• 1945 Clarke putforth the concept of
geo-stationary satellite in Science-fiction
• 1962 Satellite communication begins
with Telstar I first rectenna build
BRIEF HISTORICAL MILE-STONES
Contd….
•1963 First rectenna built
•1964 W.C. BROWN succeeded in microwave powered
helicopter using 2.45 GHz.
•1964 IEEE Conference on Energy Sources organized
session on Microwave Power Transmission
•1965-66 Commercial Satellite Communication Service
Introduced
•1968 PETER GLASER proposed Solar Power
Satellites
•1973-74 Glaser was granted a patent for possible
microwave power transmission from SPS to
earth
BRIEF HISTORICAL MILE-STONES
(Contd….)
• 1975
84% efficient microwave to DC
conversion demonstrated
• 1983 US Patent for a system for power
transmission from SPS & direct
conversion to 60 Hz, 3-Phase
• 1999-2000 SPS Exploratory Concept
examined by NASA
BRIEF HISTORICAL MILE-STONES
• 2001-2002 Technology Maturation
program for SPS pursued by NASA
• 2004 A Report on possible design of
SPS prepared by NASA
• 2007-2010 many nations in the world
considering such projects. Japan
announced plans to have its first SPS in
operation by 2040.
POSSIBLE TRANSMISSION
TECHNIQUES
• MICROWAVES
• LASER BEAMS
METHODOLOGY OF TRANSMISSION
AND UTILIZATION
• DIRECT TRANSMISSION (OF
MICROWAVE POWER) TO HOMES BY
SMALLER ANTENNA FEEDING TO
UTILITY SYSTEM/EQUIPMENT
• TRANSMISSION TO LARGE CENTRAL
EARTH STATION & FEEDING TO
TERRESTRIAL POWER SYSTEM
(POWER GRID)
MAIN SUBSYSTEMS OF SOLAR
POWER SATELLITE
• SOLAR POWER COLLECTOR AND SUBTRACKER SUB-SYSTEM
• POWER CONVERSION SUB-SYSTEM
• POWER TRANSMISSION SUB-SYSTEM
• TELEMETRY, TRACKING & COMMAND SUBSYSTEM
• ANTENNA SUB-SYSTEM
• PROPULSION & ATTITUDE STABILIZATION
SUB-SYSTEM
SOLAR POWER SATTELLITE
LOCATION OPTIONS
• GEO-SYNCHRONUS-STATIONARY
ORBIT (3600 KM FROM EARCH)
• MEDIUM EARTH ORBIT (MEO: AROUND
10000 KM)
• LOW EARCH ORBIT (LEO: AROUND
800-1000 KM)
• HIGH ALTITUDE PLATFORM (HAP:
LESS THAN 100 KM)
MICROWAVE VACUUM DEVICES
V/S SOLID STATE DEVICES
VACUUM DEVICES
– High Power
Capability
– Higher Frequency
Capability
– Large Bulk & High
Cost
– Devices Level
Integration Difficulty
SOLID STATE DEVICES
• Performance Superiority
• Lower Voltage
Requirement
• Small size and Rugged
• Compatible with MIC
• Flexibility in Circuit
Configurations
• Easy portability
• Robustness
POWER COMBINING OPTIONS
• DEVICE LEVEL
• CIRCUIT LEVEL
• SYSTEM LEVEL
POWER COMBINING OPTIONS
Contd….
CHOICE GOVERNED BY
• EFFICIENCY
• BAND WIDTH/SPECTRAL PURITY
• ISOLATION
• HIGHER ORDER MODES
• COMBINER LOSSES
• COMPLEXITIES
IMPORTANT ANTENNA PARAMETERS
•
•
•
•
•
•
•
Far Field
Directivity and its controllability
Efficiency
Gain
Impedance
Bandwidth
Beam width and spread
IMPORTANT ANTENNA PARAMTERS
Contd…..
•
•
•
•
•
Steerability
Beams multiplicity
Polarization
Size
Complexity
SOME TYPICAL ENVISAGED DATA
• FOR ABOUT 5 TO 10 GW OF GENERATED
POWER
• Solar Collectors 50 To 150 Sq.Km. depending
on quality of PV Cells and sun-trackers design
• Satellite Transmitting Antenna Size Between 1
and 1.5 Km. diameter
• Ground Rectenna around 14 Km. by 10 Km
SOME TYPICAL ENVISAGED DATA
(Contd…..)
• ACCORDING TO SUNSAT ENERGY
COUNCIL (AFFILIATED TO UNO), THE
MICROWAVE BEAM WOULD BE SO
LOW IN DENSITY THAT PERSONS CAN
WALK THROUGH IT; SAFE FOR
AEROPLANES, BIRDS ETC.
SOME TYPICAL ENVISAGED DATA
(Contd…..).
• ACCORDING TO A PHYSICIST AND
VISIONARY GERARD O’ NEILL, (1992)
OVER 99% OF MATERIAL FOR SPS
CAN BE OBTAINED FROM LUNAR
MATERIALS AND REDUCE THE COST
OF SPS CONSTRUCTION BY 97%.
CHALLENGES IN IMPLEMENTATION
• CROWDING OF GEOSTATIONARY ORBIT
• LIMITS OF REDUCED ANGULAR
SEPARATION
• ALIGNMENT AND HAND OVER
PROBLEMS WITH MEO AND LEO
• SATELLITE DIMENSIONS
• NEEDS LARGE SPACE STATION
CHALLENGES IN IMPLEMENTATION
(Contd….)
•
•
•
•
SOLAR SAILS DIMENSIONS
SATELLITE ECLIPSES
ANTENNA SIZE
FOLDING/UNFOLDING TECHNIQUES FOR
ANTENNA & SOLAR SAILS
• EFFICIENT CONVERSION OF D.C. POWER
TO MICROWAVE POWER
• OPTIMIZING SOLAR CELLS POWER
OUTPUT UNDER HARSH SPACE
ENVIRONMENT.
CHALLENGES IN IMPLEMENTATION
(Contd….)
• ACTIVE & PASSIVE DEVICES OF HUGE
POWER CAPABILITY
• EFFECTS OF FREE SPACE ATTENUATION
AND OTHER LOSSES ON TRANSMISSION
EFFICIENCY AND COMPENSATION
TECHNIQUES
• MICROWAVE INTERFERENCE TO
TERRESTRIAL SYSETMS
CHALLENGES IN IMPLEMENTATION
(Contd…..)
• EXPLORING TECHNIQUES FOR DIRECT
CONVERSION OF MICROWAVE ENERGY TO 50 HZ
3-PHASE SUPPLY
• ECONOMIC FEASIBILITY
• TECHNOLOGICAL FEASIBILITY
• RADIATION HAZARDS & SAFETY
CONSIDERATIONS
• EFFECTS ON SURROUNDINGS/ENVIRONMENT
• SOCIAL & POLITICAL CONSIDERATIONS.
SPECIAL FEATURES OF SPACE ENVIRONMENT
FOR DESIGN AND DEPLOYMENT OF SOLAR CELLS
• MULTIPLE RADIATIONS MAY DAMAGE THE
SOLAR CELLS. DAMAGE BY HIGH ENERGY
ELECTRONS AND PROTONS IS SERIOUS IN
MEOs PASSING THROUGH VAN ALLEN’S
BANDS. NEIGHBOURHOOD OF
DIFFERRENT PLANETS AFFECTS
DIFFERENTLY: e.g., NEIGHBOURHOOD OF
JUPITER PROVIDES HIGH RADIATION
ENVIRONMENT.
SPECIAL FEATURES OF SPACE ENVIRONMNET
FOR DESIGN AND DEPLOYMENT OF SOLAR CELLS
(Contd…)
• SUNLIGHT IN SPACE, UNFILTERED BY EARTH’S
ATMOSPHERE HAS A DIFFERENT SPECTRUM,
NEEDING DIFFERENT SOLAR CELL DESIGN AND
MATERIALS
• SATTELITES IN HIGH EARTH ORBITS EXPERIENCE
DRAMATIC CHANGES IN TEMPERATURE LEADING
TO EXTREME THERMAL STRESSES AND IN TURN
BIG POWER SURGES
SPECIAL FEATURES OF SPACE ENVIRONMENT
FOR DESIGN AND DEPLOYMENT OF SOLAR CELLS
(Contd…)
• MATERIAL PROPERTIES UNDER TYPICAL SPACE
ENVIRONMENT NEED SPECIAL PROVISIONS FOR
CONSISTENT PERFORMANCE AND RELIABILITY.
PROSPECTIVE CONTRIVANCES
FOR FURTHER EXPLORATIONS
•
•
•
•
USE OF LEO/MEO
HIGH ALTITUDE PLATFORMS
META-MATERIALS FOR ANTENNAS
SUPER-DIRECTIVE FEATURES FOR
ANTENNAS
• USE OF NANO-TECHNOLOGY FOR MORE
EFFICIENT PV CELLS
PROSPECTIVE CONTRIVANCES FOR
FURTHER EXPLORATIONS
(Contd….)
• NEWER LAUNCHING TECHNOLOGIES LIKE SPACE
ELEVATORS
• REPLENISHMENT TECHNOLOGY FOR SPS IN
ORBIT
• USE OF LUNAR MATERIALS BY
TRANSPORTATION FROM MOON TO SPS
• EFFICIENT DIRECT TECHNIQUES FOR
CONVERSION OF MICROWAVE POWER TO
COMMERCIAL FREQUENCY POWER.
EPILOGUE
• SUCCESSFUL IMPLEMENTATION OF SUCH A
SCHEME IS STILL INDISTINCT
• FURTHER RESEARCH AND EXPERIMENTATION
REQUIRED FOR ANY REALISATION
• APPEARS TO BE A PROMISING TECHNIQUE
• MANY NATIONS HAVE ASSIGNED AND STARTED
EXPERIMENTAL PROJECTS
• IT IS WISHED THAT INDIA SHOULD ALSO
INITIATE WORK IN THIS DIRECTION
• SPS COULD BE A SOLUTION FOR A COUPLE OF
CENTURIES UNTIL NUCLEAR FUSION
ESTABLISHES ON A FIRM FOOTING.
THANKS
ANY QUERIES?
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