Presented By: Shitole Sanket S.

WIRELESS POWER TRANSMISSION THROUGH SPS (SOLAR POWER SATELLITE)

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WIRELESS POWER TRANSMISSION (WPT)

Nicola Tesla proposed the theory of wireless power

transmission.Transmission of energy from one place to another

place without using wires. Three main systems used for WPT :• Microwaves• Resonance• Solar cells

Nicola Tesla proposed the theory of wireless power

transmission.Transmission of energy from one place to another

place without using wires. Three main systems used for WPT :• Microwaves• Resonance• Solar cells

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WHY WPT ???

ReliableEfficientFastLow maintenance costCan be used for short range or long rangeReduction of losses during transmission and distribution

of electrical energy.Need for grids, substations etc. are eliminated.Noble alternative for electrical transmission.

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TYPES OF WPT ... There are mainly three major types of wireless energy transfer

Short range – INDUCTIVE COUPLING

Medium range – RESONANT COUPLING

Long range power transfer – ELECTROMAGNETIC

RADIATION

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HOW SPS WORKS ???

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FLOW CHART OF SOLAR POWER TRANSMISSION

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OVERVIEW OF SYSTEM DESIGN.....

It consists of :

I. Solar Panel.

II. Spacetenna ( antenna on satellite ).

III. Rectenna ( RECTifyin g anTENNA).

IV. Orbit selection Systematic view.

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SOLAR PANELSet of solar photovoltaic modules electrically

connected and mounted on a supporting structure.Photovoltaic module is a packaged , connected

assembly of solar cells.Solar panels use photons(light energy) from sun to

generate electricity through photovoltaic effect.Solar panels were first used in space in 1958.

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SPACETENNA: (Antenna on Satellite) Spacetenna is a triangular prism with a length of 800 m and sides

of 100 m.The transmitting antenna on the horizontal under surface faces

the earth, and the other two sides of the prism carry solar arrays.The faces of prism are embedded with photovoltaic cells .These

cells would convert solar energy into electricity, which in turn power onboard , Microwave Generator.

The microwave thus produced travels through atmosphere & collected by RECTENNAS on earth.

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CONFIUGRATION OF SPACETENNA..

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RECTENNA: (RECTIfying anTENNA) mesh of an array of dipole antennas connected to diodes converting the radio frequency signal into DC voltage, which is then converted into regular AC electricity which is wired to homes, factories etc.

It can be considered as a base station of Geosynchronous satellite. Microwaves of 2.45 GHz frequency is used to transmit power from satellite to rectenna.

. A simple rectenna can be constructed from a Schottky diode placed between antenna dipoles as shown in Fig.

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ORBIT SELECTION SCHEMATIC VIEWIn LEO, a 11,00 Km altitude equatorial orbit will be used. This choice minimizes the transmission cost and the distance of power transmission from space.

If it was in GEO ( that is 35,800 Km from the earth ) then the transmitting antenna would have to be 40 times larger than LEO one- or else the receiving station would have to be 40 times larger.

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5,000 MW Receiving Station (Rectenna).This Station is about a mile & a half long in US.

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WHY TO USE SPS ?More intense sunlight.Unlimited energy resource.Energy delivered anywhere in the world.Zero fuel cost.Zero co2 emission – environment safe.Waste heat is radiated back into space.No air or water pollution is created during the

generation.Concept is simpler than the other most power

systems here on the earth.

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...SPS doesn’t use up the valuable surface area

on the earth.Solar radiation can be more efficiently

collected.Space gets full power 24 hours a day.No effect of storms.Eco- friendly and maintenance free energy

resource.

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DISADVANTAGES...

Issues identified during DOE study : Complexity – long years to complete.

Size- 6.5 miles long by 3.3 miles wide.Transmitting antenna about 1.5 mile in diameter (1 km)Cost – prototype would have cost $74 billion.Interference with communication satellitesWould require a network of 100’s of satellite.Heavy Launch costThe large scale of space solar power require international

financing.

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CONCLUSION...SPS is still more expensive than ground

based solar power & other energy sources. Yet even now, a small SPS system could be economically justified to provide unavailable emergency power for natural disaster situations, urban blackouts & satellite power failures.

For WPT via SPS to become reality, we require:

Government support.Cheaper launch prices.Involvement of private sector.

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REFERENCES...

W.C. Brown, “Experiments Involving a Microwave Beam to Power and Position a Helicopter”, IEEE Transactions on Aerospace Electronic Systems. Vol. AES-5, no. 5, pp 692-702

Satellite Power System Concept Development and Evaluation Program July 1977 - August 1980. DOE/ET-0034, February 1978.

Tesla, N., “The transmission of electric energy without wires”, The thirteenth Anniversary

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