SEMINAR PROJECT PRESENTATION ON

WIRELESS POWER TRANSMISSION FOR SOLAR POWER SATELLITE

Submitted by:Akanksha trikha04010403010

Guide:Mr. vineet dahiya

INTRODUCTION

• SOLAR POWER : INEXAUSTIBLE(RENEWABLE) ENERGY RESOURCE.

• We can, directly convert solar energy into electrical energy with the use

of solar cells, but sunlight diffuses at night time from the earth.

• The solution is wireless power transmission from space through a system consisting of SPS(Solar Power Satellite) and RECTENNA (RECtifying anTENNA) by Microwaves.

• Wireless Power transmission (WPT) is a useful and convenient technology that can be employed to collect solar energy and concentrate on earth surface without the need for a wire connection called as solar power satellites (SPS). Solar Power Satellite is an energy system which collects solar energy in space and transmits it to the ground.

A CONCEPTUAL VIEW OF THE SYSTEM

PRINCILPLE• Modern techniques enables us to create a

platform in space carrying solar batteries, generators converting electric current worked out by them into the Electromagnetic field energy of ten centimeter range (microwaves) and antenna forming electromagnetic wave beam

• On the earth, the other antenna (rectenna) receives the beam and it is converted into electric current again.

• The principal advantage of the space location is its independence of weather and day-night cycle and is pollution free.

• It is shown that a correct choice of the field distribution on the radiation antenna allows us to increase the wireless power transmission efficiency and to lessen its cost(As Space Solar Power Stations are costly because of sheer size of Radiating & Receiving Antennas.).

• Antenna and Rectenna sizes are chosen such that the rectenna is situated in the antenna’s Fresnel’s area.

• This Design has many Advantages from Environmental point of view.

THE WIRELESS POWER TRANSMISSION SYSTEM'S SIMULATION

OVERVIEW OF SYSTEM DESIGNConstruction of spacetenna and rectenna to increase the effectiveness of WPT.

• SPACETENNA:(THE ANTENNA ON SATELLITE)

1.Spacetenna is a triangular prism with a length of 800 m and sides of 100 m.

2.The main axis lies in the north-south direction, perpendicular to the direction of orbital motion.

3. The transmitting antenna on the horizontal under-surface faces the Earth, and the other two sides of the prism carry solar arrays.

4.The faces of the prism are embedded with photovoltaic cells. These Photovoltaic cells would convert sunlight into electrical current, which would, in turn, power an onboard microwave generator.

5. The Microwave thus produced Travels through Atmosphere & is collected by RECTENNAS on Earth.

6. The spacetenna is composed of pilot signal receiving antennas followed by detectors finding out the location of the rectenna on the earth, power transmission antenna elements and phase control systems.

THE SPACETENNA STRUCTURE

7. Moreover, the pilot signal frequency and a frequency for the energy transmission are different from each other.

8. Using two kinds of frequency for the power transmission and the pilot signal prevents each other from interfering and makes it possible to find out the accurate direction of a specified rectenna.

• RECTENNNA :(RECTIFYING ANTENNA)

1.A Rectenna can be considered as a base station for a geo-stationary satellite. Microwaves of 2.45 GHz frequency are used to transmit power from the satellite to the rectenna.

2. It consists of a mesh of an array of dipole antennas connected to diodes to convert the radio frequency energy to DC voltage, which is then converted to regular AC electricity and wired to homes, factories, etc.

3. A simple reflector plane could be added to the mesh to improve the efficiency to 50%.

RECTENNA OPERATION

Microwave Power Transmission How the power gets to Earth

From the Satellite • Solar power from the satellite is sent to Earth using a

microwave transmitter• Received at a “rectenna” located on Earth• Recent developments suggest that power could be sent to

Earth using a laser

Microwave vs. Laser Transmission

Microwave• More developed• High efficiency up to

85%• Beams is far below the

lethal levels of concentration even for a prolonged exposure

• Cause interference with satellite communication industry

Laser• Recently

developed solid state lasers allow efficient transfer of power

• Range of 10% to 20% efficiency within a few years

• Conform to limits on eye and skin damage

Reliability• Ground based solar only works during clear

days, and must have storage for night• Power can be beamed to the location where it is

needed, don’t have to invest in as large a grid• A network of low orbit satellites could provide

power to almost any point on Earth continuously because one satellite would always be in range

Issues :• Would require a network of hundreds of satellites

(Air Force currently track 8500 man made objects in space, 7% satellites)

• Would make telecommunications companies into power companies

Advantages•Unaffected by day-night cycle, weather or seasons. Optimized advances may enable 21 hour power supply per day.

•This is an eco-friendly, renewable and maintenance free energy resource unlike the conventional fuels.

•As the equipment is positioned in space, it is occupies no land area and remains unaffected by harsh weather conditions. Rectennas can share land with farms.

•The spacetenna could direct energy to any rectenna on earth within the range of its steering angle, which could satisfy the energy requirements of all the equatorial countries.

•Waste heat is re-radiated back into space, instead of warming the biosphere.

Current Developments• Project in Development in

Japan• Goal is to build a low cost

demonstration model by 2025• 8 Countries along the

equator have agreed to be the site of a rectenna

Contd..Synthesizing the wireless power transmission, it can be concluded that to make the SPS concept commercially viable, it becomes a priority to improve its efficiency and the cost per watt. This can be achieved by:

1.Placing the Rectenna within the Fresnel area of the transmitter.

2. Placing the transmitting antenna in the LEO orbit to reduce installation cost and the distance of transmission.

3. Using a discontinuous equidistant array with quasi Gauss distribution.

4. Using a discontinuous non-equidistant array with uniform distribution.

BOTTOMLINE: Will be a boon as we are running out of fossil fuels.

Conclusion• More reliable than ground based solar power• In order for SPS to become a reality it several

things have to happen: Government support Cheaper launch prices Involvement of the private sector

Nevertheless with all the challenges that face wide-scale deployment of this new technology wireless power transmission for solar power satellite is still considered as a next-generation power transmission system.

*******THANK YOU******