WITRICITY (WIRELESS ELECTRICITY)
-THE END OF THE PLUG
EI III year (3K)
Miss. Vibha shrivastava
UCER (EC & EI Dept.)
In our present electricity generation system we waste more than half
of its resources. Especially the transmission and distribution losses
are the main concern of the present power technology. These losses
imply that our present system of electrical distribution is only 70-
We have to think of alternate state - of - art technology to transmit
and distribute the electricity. Now- a- days global scenario has been
changed a lot and there are tremendous development in every field.
We have to keep pace with the development of new power
technology. The transmission of power without wires may be one
noble alternative for electricity transmission.
WITRICITY stands for wireless electricity.
The transmission of energy from one place to another
without using wires. It eliminates the use of cables.
It is the transfer of power to a device over the air. Power
source (transmitter) provides power to the devices whereas
capture device (receiver) captures it.
Efficiency achieved was around 40%
Used frequencies are 1MHz &10MHz
Intel is working on it
HISTORY OF WIRELESS POWER
In 1899, Sir Nikola Tesla proposed a
method of Wireless Power Transmission.
His vision was for “World Wireless
The 187 feet tall tower was built to
broadcast energy. So that, all people could
have access to free energy but shortage
of fund led to nonoperation.
Tesla was able to transfer energy from
one coil to another coil and he managed
to light 200 lamps from a distance of
As it was in Radiative mode, most of the
power was wasted and had less efficiency.
The idea of Tesla is taken into research
after 100 years by a team led by Marin
WIRELESS POWER TECHNOLOGY
Various methods of wireless power transmission:-
Inductive Coupling (works on mutual induction)
Resonant Inductive Coupling (resonance & inductance)
Air Ionization (ionized air due to high field)
Microwave Power Transmission (MPT) (capturing
microwaves using rectenna)
LASER power transmission
Witricity works on the principle of Resonant Inductive
5/4/2016 Wireless Power Transmission 6
Resonant inductive coupling or electrodynamic induction is the
wireless transmission of electrical energy between two magnetically
coupled coils that are part of resonant circuits tuned to resonate at the same
A transmitter coil in one device transmits electric power across an
intervening space to a receiver coil in another device.
The capacitor and inductor forms the resonator. Charge oscillates between
inductor (as magnetic field) and capacitor (as electric field). This generates
an oscillating magnetic field.
This type of oscillation is called resonance if the reactance's
of the inductor and capacitor are equal.
Because the coil is highly resonant, any energy placed in the coil dies away
relatively slowly over very many cycles; but if a second coil is brought near
it, the coil can pick up most of the energy before it is lost, even if it is some
Coil provides the inductance which induces current.
Capacitor is connected parallel to the coil
Energy will be shifting back and forth between magnetic field surrounding
the coil and electrified around the capacitor.
1. Magnetic coil (Antenna A) is housed in a box and can be set in
wall or ceiling.
2. Antenna A, powered by mains, resonates at a specific
3. Electromagnetic waves transmitted through the air.
4. Second magnetic coil (Antenna B) fitted in laptop/TV etc.
resonates at same frequency as first coil and absorbs energy.
5. Energy charges the device.
Automatic wireless charging of electronics in home, cars,
Wireless charging pads(Mobile phones, Laptops, Game
Direct wireless power and communication interconnections
at points of use in harsh environments.
In Drilling, Mining, Underwater etc.
Automatic wireless charging for existing electric vehicle
In Golf carts, Cars etc.
Safe, fairly efficient, good range
No need of line of sight.
Magnetic fields interact weakly with biological
No wire, No batteries i.e. No e-waste
• Significant decluttering of space
• No need for meter rooms and electrical closets.
• Maintenance cost will be saved.
Can be one-to-many.
Devices using RIC technique are highly portable.
Distance constraint:-Transmissions possible only in
few meters. Efficiency decreases with distance.
Possibility of “energy theft”
The resonance condition should be satisfied and if any
error exists, there is no possibility of power transfer.
Initial cost is high
In RIC, tuning is difficult
High frequency signals must be the supply.
• Need for standardization and adaptation. So no
overheating occurs because of different voltages.
FUTURE OF WITRICITY
• If we apply this idea to the whole city, we might not have
to use any wired cable. Moreover, in the future, it would
save the material cost, and “WE CAN SAVE THE WORLD,
The concept looks to be costly initially but the cost is
not estimated yet.
In terms of economic theory, many countries will
benefit from this service. The private, dispersed sub-
stations will be needed.
No power cords will be necessary
Monthly electric utility bills from old-fashioned, fossil-
fuelled, loss-prone electrified wire-grid delivery services
will be optional.
The transmission of power without wires to any terrestrial
distance is not a theory or a mere possibility, it is now a reality.
Dr.Tesla is the pioneer of this invention.
Wireless electricity have tremendous merits like high
transmission integrity and Low Loss (90 – 97 % efficient)and
eliminate the need for an inefficient, costly, and capital
intensive grid of cables, towers, and substations.
It has negligible demerits like energy theft and difficult tuning.
Many countries will benefit from this service.
The wireless transfer of electricity has been a sci-fi dream up
to this point, and truly, if electricity could simply be in the air, in
the same way radio waves and Wi-Fi signals are, it would
change the world.