1

PRESENTED by-NIKHIL GAURAVDEPARTMENT OF ELECTRICAL ENGINEERINGM.TECH 3rd sem

OVERVIEWINTRODUCTIONDEFINITIONHISTORYTYPES OF WPTMICROWAVE vs LASER TRANSMISSIONWHY MICROWAVES TRANSMISSIONWORKING OF SPSFLOWCHART OF SOLAR POWER TRANSMISSIONOVERVIEW OF SYSTEM DESIGNADVANTAGES AND DISADVANTAGESAPPLICATIONSCONCLUSIONREFERENCES

2

INTRODUCTION• One of the major issues in power system is the losses occurring during

the transmission and distribution of electrical power.• The percentage of loss of power during transmission and distribution

is approximated as 26%.• The main reason for power loss during transmission and distribution is

the resistance of wires used in a grid.• According to the World Resources Institute (WRI), India’s electricity

grid has the highest transmission and distribution losses in the world– a whopping(extremely large) 27-40%.

• Tesla has proposed methods of transmission of electricity using electromagnetic induction.

3

DEFINITION• As the word wireless means “without wire”. • Wireless energy transfer or wireless power is the transmission of

electrical energy from a power source to an electric load without interconnecting man made conductors.

4

HISTORY

Nikola Telsa – Experimented in 1899• Imagined a global wireless power distribution system

NASA – in 1958 invented solar panel used for solar power satellite

William C. Brown – Experimented in 1964• Established microwave to electricity conversion

• .

5

Types of WPTThere are mainly three major types of wireless energy transfer:1. Near Field Technique

a) Inductive couplingb) Resonant Inductive couplingc) Air Ionization

2. Far Field Techniquea) Microwave Power Transferb) Laser Power Transfer

6

Microwave vs. Laser Transmission

MICROWAVE

LASER

More developed.High efficiency up to

85%.Beams is far below the

lethal(deadly) levels of concentration even for a prolonged exposure.

Cause interference with satellite communication industry.

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.

7

8

Why Microwave transmission?

Working of SBSP

9

Flow chart of Solar Power Transmission

10

Overview of System DesignIt consists of : Solar Panel. Spacetenna ( antenna on satellite ). Rectenna ( RECTifyin g anTENNA). Orbit selection Systematic view.

11

SOLAR PANEL• Solar panels were first used in space in 1958.• 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.

12

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

100m.• 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.

13

Configuration of Spacetenna

14

RECTENNA:(RECTIfying anTENNA)• A rectenna is a rectifying antenna—a special type of antenna that is

used to convert electromagnetic energy into direct current (DC) electricity.

• It is a 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.

15

16

5,000 MW Receiving Station. This Station is about 1 and a 1/2 mile long in US.

17

Orbit Selection Schematic View

•In 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.

18

ADVANTAGES OF USING SBSPMore 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.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.

19

ADVANTAGES OF USING SBSP(cont..)No effect of storms.Eco- friendly and maintenance free energy resource.Wireless transmission is useful in cases where interconnecting wires

are inconvenient, hazardous or impossible.

20

DISADVANTAGES OF USING SBSPIssues identified during DOE study :-

• Complexity – long years to complete.• Size- 10.4km long by 5.28km wide.

Transmitting antenna about 2.4km 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 cost.The large scale of space solar power require international financing.

21

APPLICATION

• Energy to remote areas• Can broadcast energy globally (in future).

22

CONCLUSIONTransmission without wires- a reality.Efficient.Low maintenance cost, but high initial cost.Better than conventional wired transfer.Energy crisis can be decreased.Low loss of energy. In near future, world will be completely wireless.In order for SBSP to become a reality several things have to happen:

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

23

REFRENCESW.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.

Ralph H. Nansen solar power industries “WIRELESS POWER TRANSMISSION :The key to solar power satellites” IEEE AES system magazine , January 1996.

Brown, W. C., “Beamed microwave power transmission and its application to space”, IEEE Trans. Microwave Theory Tech.,vol.40.

Kaya, N., S. Ida, Y. Fujino, and M. Fujita, “Transmitting antenna system for airship demonstration of Space Energy and Transportation” IEEE Vol.1. 24

REFRENCES(cont..)Hatsuda, T., K. Ueno, M. Inoue, “Solar power satellite interference

assessment”, IEEE, Vol. 3, No. 4, Dec. 2002Transmission Technology”, IEEE Microwave Magazine, December

2002."Spacebased solar power". ESA–advanced concept team. Retrieved

August 2015."Space Based Solar Power". United States Department of Energy

(DoE). 6 March 2014."Basic Plan for Space Policy" (PDF). June 2, 2009. Retrieved May 21,

2016.

25

1