Vardhaman college of engineering

ELECTRICAL ENGINEERING

WIRELESS POWER TRANSMISSION

VIA SOLAR POWER SATELLITE

BY:-V.NAVYA HARITHA

B.NEELAVATHI

CONTENTS

• Brief study of WPT• Introduction to SPS• How SPS works• Flow chart of solar power transmission• Advantages & Disadvantages• Conclusion

WIRELESS POWER TRANSMISSION(WPT)

• The transmission of energy from one place to another without using wires.

• Conventional energy transfer is using wires

• But, the wireless transmission is made possible by using various technologies…..

history WPT• Sir NICOLAI TESLA: was the first one to propose and research the idea of wireless transmission in 1899, since than many scholars and scientists have been working to make his dream a reality. Tesla was able to transfer energy from one coil to another coil He managed to light 200 lamps from a distance of 40km SPS• The SPS concept, originally known as Satellite Solar Power System ("SSPS") was first

described in November 1968.• In 1973 Peter Glaser was granted for his method of transmitting power over long distances (e

g from an SPS to the Earth's surface) using microwaves from a very large (up to one square kilometer) antenna on the satellite to a much larger one on the ground, now known as a Rectenna.

Why not wires???i. As per studies, most electrical energy transfer is through wires.

ii. Most of the energy loss is during transmission

iii. On an average, more than 30%

iv. In India, it exceeds 40%

WHY WPT ???

• Reliable• Efficient• Fast• Low maintenance cost• Can be used for short range or long range• Reduction of losses during transmission and

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

IS WPT SAFE???

• Human beings or other objects placed between the transmitter and receiver do not hinder the transmission of power.

• Magnetic field tend to interact very weakly with the biological tissues of the body, and so are not prone to cause any damage to any living being.

…Types of WPT… 1) Ground based power transmission 2) Space based power transmission

Space based power transmission

But Space-based power transmission is preferred over Ground based power transmission Ground is (obviously) cheaper per noontime watt, but:· Space gets full power 24 hours a day . No storage required for nighttime power · Space gets full power 7 days a week – no cloudy days · Space gets full power 52 weeks a year . No long winter nights, no storms, no cloudy seasons · Space delivers power where it’s needed . Best ground solar sites (deserts) are rarely near users · Space takes up less, well, space . Rectennas can share land with farming or other uses.

HOW SPS WORKS???

Solar Power Satellites (SPS) have proposed to collect solar energy in space and beam it down to the Earth.

Producing electricity from sunlight in space is not a new or untried technology. What has never been tried before is transmitting that power back to Earth for our use.

The Solar Power Satellite (or "Space Solar Power," SPS) is a concept to collect solar power in space, and then transport it to the surface of the Earth by microwave beam, where it is converted into electrical power for terrestrial use.

Being a clean and safe energy design, space-based solar power has the potential to play a significant role in solving global energy and environmental problems.

Introduction

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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.

Four basic steps involved in the conversion of solar energy to electricity and delivery are:

Capture solar energy in space and convert it to electricity

Transform the electricity to radio frequency energy and transmit it to Earth

Receive the radio frequency energy on Earth and convert it back to electricity

Provide the electricity to the utility grid

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FLOW CHART OF SOLAR POWER TRANSMISSION

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SOLAR PANEL

• Set 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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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.

Rectenna:

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

Advantages:Unlimited energy resource.Energy delivered anywhere in the world.Zero fuel cost.Zero CO2 emission.Minimum long-range environmental impact.Solar radiation can be more efficiently collected in

space.Disadvantages:Storage of electricity during off peak demand

hoursHigh initial cost and require much time for

construction.

Summary

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