A presentation on upcoming Solar Power Technologies as a viable means of efficiently harnessing solar energy. Part of Self Study Phase-2 at RV College of Engineering, Bangalore. Part 1 is here: http://www.slideshare.net/Jayanth-R/solar-power-satellites

1. Solar Power
Satellites
A RADICAL SOLUTION TO THE ENERGY CRISIS
PHASE - II
RV College of Engineering
Department of Electronics and Communication
Presented by: R Jayanth

2. Methodology
• Phase-I
• Introduction to Space Based Solar Power Systems (SBSP).
• Need for SBSP.
• Thermodynamic Cycles for Solar Power generation (Brayton Cycle).
• Reception of Solar Power on Earth by means of Rectifying Antennae.
• Calculation of Efficiency of Rectification.
• MATLAB graphs ofWireless PowerTransfer circuits.
• Phase-II
• Brief history of Solar Power Satellite (SPS)Technology.
• Various SPS models proposed.
• Mechanism of transmission of power through microwaves.
• Rankine Cycles as an alternative to Brayton Cycle for power generation.
• Satellite orbit simulation using MATLAB.
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3. Recap
• The world’s non-renewable energy resources are being
consumed at an ever increasing rate.
• Solar Power Satellites are a radical new solution to this problem.
• They are a means of tapping into the almost infinite energy
reserves of the sun in a more efficient way than can be done on
earth.
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4. History
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• The concept of Solar Power Satellites was first
conceived by IsaacAsimov, in his 1961 short story,
‘Reason’.
• In 1973 Peter Glaser was granted a U.S. patent for his
method of transmitting power over long distances.
• NASA carried out a small-scale study in 1974.
• Between 1978 and 1986, the Congress authorized
the Department of Energy (DoE) and NASA to jointly
investigate the concept.
• On Nov 2, 2012, China proposed space collaboration
with India that mentioned SBSP.

5. Proposed SPS Designs
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6. Electronics
• Transmission of 50-60Hz of of
electrical energy from the generation
point to the consumer without any
physical wires is yet to mature as a
viable technology.
• The microwave transmission system
has three aspects:
1.The conversion of direct power from
the photovoltaic cells, to microwave
power on the satellites on
geosynchronous orbit above the Earth.
2.The formation and control of
microwave beam aimed precisely at
fixed locations on the Earth’s surface.
3.The collection of the microwave
energy and its conversion into electrical
energy at the earth’s surface.
Wireless Power Transmission
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7. Electronics
Magnetron
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• The generation of microwaves is done with a device called a
magnetron.

8. Electronics
• 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.
• It consists of a cathode which is placed at the
centre and has a ring shaped anode with
cavities surrounding it.
• A permanent magnet is placed beneath the
anode.
• The cathode is heated and a potential is
applied between anode and cathode.
• Electrons get liberated from the cathode, and
take a helical path to the anode.
• As the electrons pass the cavities in the
anode, microwaves are generated.
Magnetron
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9. Mathematics
• Vectors are used to represent the position of the satellite w.r.t.
the earth.
• A combinations of vectors and calculus is used to derive the
equations for all the parameters related to the satellite orbit.
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10. Mathematics
Kepler’s Laws
• Kepler’s Laws are mathematically proved using the concepts of limits, integration and
differentiation.
• The second law states that a line between the sun and the planet sweeps equal areas in
equal times.
The orbital area, ∆A, swept out by the radius vector r as it moves through a small angle ∆θ in a
time interval ∆t, is given as
∆A =
1
2
r(r∆θ)
Then the areal velocity of the orbit, denoted by dA/dt, can be shown to be constant, as
follows:
dA
dt
=
lim
∆t→0
∆A
∆t
=
lim
∆t→0
1
2
r2∆θ
∆t
=
1
2
r2 𝜃 =
1
2
h= constant
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11. Mathematics
Solar Radiation Pressure
It is assumed that a fraction, ρs, of the impinging photons is
specularly reflected, a fraction, ρd, is diffusely reflected, and a
fraction, ρa, is absorbed by the surface.
ρs + ρd + ρa = 1
The solar radiation pressure (SRP) force acting on an ideal flat
surface is then expressed as
For an ideal case of a perfect mirror:
Also, for an ideal case of a black body:
For most practical cases of satellites with small pitch angles
force per unit mass is:
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12. Mechanical Engineering
• It is another alternative to using photovoltaic cells in Solar power Satellites.
• The energy from the sun is converted into electrical energy with the help of a
working fluid that cycles repeatedly through the system.
Solar Rankine Cycle
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13. Mechanical Engineering
• The working fluid gets heated by using the energy from the sun.
• It undergoes constant pressure heating.
• The high temperature and pressure fluid causes the blades of the turbine to
rotate, and thus electricity is generated.
• The waste heat is rejected by the radiator.
• The fluid gets pumped into the heater again, and the cycle repeats.
Solar Rankine Cycle
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14. Mechanical Engineering
• The Rankine cycle studied by NASA uses potassium as the working fluid.
• Potassium Rankine cycles show lower efficiencies than the steam cycles.
• However steam cycles require large radiator size since due to low heat
rejection rates of water when compared to potassium.
• The difference between Brayton cycle and Rankine cycle is that the Brayton
cycle is normally an open cycle, and uses a constant phase working fluid,
while the opposite is true for the Rankine cycle.
Solar Rankine Cycle
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15. Computer Science
• Simulation is a necessary stage in the
development of any new technology.
• MATLAB (matrix laboratory) is a multi-
paradigm numerical computing
environment and fourth-generation
programming language.
• It can be used to generate graphs and
models using input in the form of
programs.
• Satellite orbit simulation is crucial for
both launch operations and long term
tracking of the satellite.
Simulation of Satellite Orbit
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16. Computer Science
Simulation of Satellite Orbit
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17. References
[1] BongWie, “IntegratedOrbit, Attitude, and Structural Control Systems
Design for Space Solar Power Satellites”, Arizona State University, 2001
[2] ,N. Shinohara, “Wireless PowerTransmission for Solar Power Satellite
(SPS)”, Kyoto University, 2014
[3] Space Research Associates Inc., “Solar Power Satellites Built of Lunar
Materials”, Space Studies Institute, 1985
[4] NancyTeresa Cabrera, “MATLAB® GUIVisualization of Classical Orbital
Elements”,California Polytechnic StateUniversity, 2010
[5] Debarghya Das, “Satellite Orbit Analysis and Simulation (in MATLAB)
[VIDEO]”, 2012
[6] National Space Society Archives (http://www.nss.org/)
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