The document discusses the history and development of wireless transmission of electricity (WiTricity), highlighting key scientists and concepts involved in the technology. It covers various methods of wireless power transmission, including induction, electromagnetic radiation, and resonant tunneling, along with their advantages and drawbacks. While the technology presents potential benefits such as reduced energy costs and elimination of power theft, concerns exist regarding environmental impact and interference with communication systems.

1. By: Abhinav Goel
Tarun Sharma
Avinash

2. Wireless Transmission of Electricity (Witricity)
concept originated during turn between 19th
and 20th century. Then scientists who
contributed to this technology are –
 Nickola Tesla
 William C Brown
 Bill Brown
 Hidetsugu Yagi

3.  First scientist to come up
with the idea of Wireless
Power Transmission(WPT).
 Able to light lamps over
25 miles away without
using wires (Wardenclyffe
tower experiment).
 Used oscillators to
energize primary coil
attached to the power
source.

4.  Induction
◦ Electrodynamics
◦ Electrostatic
 Electromagnetic Radiation
◦ Laser
◦ Microwaves
 Evanescent Wave Coupling

5.  Principle: Mutual Induction between isolated
coils or conductors.
-Electrodynamics (Electromagnetic coupling)
-Electrostatic (Capacitive Coupling)
 Transformer is a basic example.
 The main drawback to induction is the short
range.
 Magnetic field spreads in all directions
wasting a large amount of energy.

6.  Electricity transmitted by converting it into
electromagnetic waves.
 Antennas of electronic devices will receive
waves converting them back to electrical
energy.
 Mainly, two types of e.m. waves are used-
-Lasers
-Microwaves
 A big disadvantage is that e.m. waves can
harm the environment & even living beings

7. Microwave & Laser Transmission
• Microwave • Laser
– Electrical energy converted – Electrical energy
to Microwaves and beamed
to a large antenna converted to beam fired
(Rectenna) that converts it at a receiving target,
to D.C. electricity. (Power Beaming) & is
– More developed converted back to power.
– High efficiency up to 85% – Range of 10% to 20%
– Beams is far below the efficiency within a few
lethal levels of years
concentration even for a
prolonged exposure – Conform to limits on eye
and skin damage.
– Cause interference with
satellite communication – Victim of atmospheric
system. absorption.

8.  In 2006 MIT researchers discovered an efficient
method to transfer power.
 Transfer power using non-radiative.
Electromagnetic energy Resonant Tunnelling.
 Does not disturbs communication system.
 Wastage of energy is small.
 No need of line of sight between transmitter and
receiver as in lasers.
 Most efficient way to transmit Power wirelessly
introduced up till now.
 Negative health effects.

9. Electromagnetic energy Resonant Tunnelling
 Curved coil of wire makes an inductor.

.
 A capacitance plate which can hold a charge attaches
to each end of the coil.
 As electricity travels through this coil the coil begins
to resonate.
 Electricity traveling along an e.m. wave can tunnel from one coil to
the other as long as the both have the same resonant frequency.

10.  For small portable electronic devices electrical
energy can be converted to radio signals and can
be transferred to the device which receives radio
frequency radiation and converts it to DC
electricity that could be stored in a battery for
use.
 Electrical energy can propagate around the world.
Power demands differ at different time, high
demands during day and low during night . So,
the extra power available during the night could
be transmitted to the side of the planet where it
is day time.

11. Merits: Demerits
 Eliminates use of existing
high-tension power • The Capital Cost for
practical implementation
transmission line cables, of WPT seems to be very
towers and sub stations. high.
 Facilitates transmission • Microwaves interferes with
of energy on a global the present
communication systems.
scale.
• Develops reactive power
 Low Energy costs. at a small frequency that
 The power failure due to is very biologically
short circuit would never compatible and harmful to
environment & living
exist. beings on over exposure.
 Power theft would be not
possible at all.

12.  Wireless transmission is now a reality & is in
development.
 Will make Transmission system more
economical, cheap & reduce pollution.
 Merits of this technology overshadow its
demerits.

13. Thank You