Wireless energy transmission is the transmission of electrical energy from a power source to an electrical load without man-made conductors.
Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible. The problem of wireless power transmission differs from that of wireless telecommunications, such as radio.
In the latter, the proportion of energy received becomes critical only if it is too low for the signal to be distinguished from the background noise. With wireless power, efficiency is the more significant parameter.
A large part of the energy sent out by the generating plant must arrive at the receiver or receivers to make the system economical.
Usually, this process involves a phenomenon known as electromagnetic induction. Other methods, particularly radio-frequency (RF) microwaves and laser beams, have also been used.
The Serbian-American scientist Nikola Tesla first observed electromagnetic induction in the latter part of the 19th century. He noticed that when a strong alternating current (AC) passed though a coil of wire, a nearby coil acquired a weaker AC at the same frequency, even when the two coils were not physically connected.
The extent of this effect depended on the distance between the coils, and also on their relative orientation. The greatest electromagnetic induction occurred when the coils lay along a common axis in close proximity. This discovery led to the development of the transformer, a major component of electrical systems today.
Microwaves concentrate RF electromagnetic fields into powerful beams that can travel over greater distances than simple induction coils (such as the ones used by Tesla) allow. However, for public safety reasons, the Federal Communications Commission (FCC) limits the maximum amount of power that such systems can use in the United States. A receiving antenna, usually a dish, picks up the transmitted microwave energy, and a converter circuit changes it into usable electricity.
Lasers can concentrate considerable energy in an extremely narrow beam that travels over great distances through space or clear air. A photovoltaic cell (PV cell) can intercept the visible or infrared (IR) rays from a distant laser and convert that energy to direct-current (DC) electricity. The DC can, in turn, charge the batteries for a consumer device such as a personal computer (PC), eBook reader, or cell phone. However, even this technology cannot yet convey the massive amounts of energy needed to electrify cities. For that purpose, high-voltage utility transmission lines remain the option of choice.
How Wireless Energy Transfer Works
In the house of the future, wire-free energy transfer could be as easy as wireless internet.
A start up named WiTricity is working on it as well
If all goes to WiTricitys plans, smartphones will charge in your pocket as you wander around, televisions will flicker with no wires attached, and electric cars will refuel while sitting on the driveway.
WiTricity has already demonstrated the ability to power laptops, cell-phones, and TVs by attaching resonator coils to batteries and an electric car refueler is reportedly in the works.
Imagine driving your car home and never going to have to go to the gas station and never going to have to plug it in.
Some of methods using which we can achieve Wireless energy transmission are
Electromagnetic induction
Electrodynamic induction method
Electrostatic induction method
Electromagnetic radiation
Microwave method
Laser method
Magnetodynamic coupling
Electrical Conduction
Terrestrial transmission line with atmospheric return
Terrestrial single-conductor surface wave transmission line
Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible. The problem of wireless power transmission differs from that of wireless telecommunications, such as radio.
In the latter, the proportion of energy received becomes critical only if it is too low for the signal to be distinguished from the background noise. With wireless power, efficiency is the more significant parameter.
A large part of the energy sent out by the generating plant must arrive at the receiver or receivers to make the system economical.
Usually, this process involves a phenomenon known as electromagnetic induction. Other methods, particularly radio-frequency (RF) microwaves and laser beams, have also been used.
The Serbian-American scientist Nikola Tesla first observed electromagnetic induction in the latter part of the 19th century. He noticed that when a strong alternating current (AC) passed though a coil of wire, a nearby coil acquired a weaker AC at the same frequency, even when the two coils were not physically connected.
The extent of this effect depended on the distance between the coils, and also on their relative orientation. The greatest electromagnetic induction occurred when the coils lay along a common axis in close proximity. This discovery led to the development of the transformer, a major component of electrical systems today.
Microwaves concentrate RF electromagnetic fields into powerful beams that can travel over greater distances than simple induction coils (such as the ones used by Tesla) allow. However, for public safety reasons, the Federal Communications Commission (FCC) limits the maximum amount of power that such systems can use in the United States. A receiving antenna, usually a dish, picks up the transmitted microwave energy, and a converter circuit changes it into usable electricity.
Lasers can concentrate considerable energy in an extremely narrow beam that travels over great distances through space or clear air. A photovoltaic cell (PV cell) can intercept the visible or infrared (IR) rays from a distant laser and convert that energy to direct-current (DC) electricity. The DC can, in turn, charge the batteries for a consumer device such as a personal computer (PC), eBook reader, or cell phone. However, even this technology cannot yet convey the massive amounts of energy needed to electrify cities. For that purpose, high-voltage utility transmission lines remain the option of choice.
How Wireless Energy Transfer Works
In the house of the future, wire-free energy transfer could be as easy as wireless internet.
A start up named WiTricity is working on it as well
If all goes to WiTricitys plans, smartphones will charge in your pocket as you wander around, televisions will flicker with no wires attached, and electric cars will refuel while sitting on the driveway.
WiTricity has already demonstrated the ability to power laptops, cell-phones, and TVs by attaching resonator coils to batteries and an electric car refueler is reportedly in the works.
Imagine driving your car home and never going to have to go to the gas station and never going to have to plug it in.
Some of methods using which we can achieve Wireless energy transmission are
Electromagnetic induction
Electrodynamic induction method
Electrostatic induction method
Electromagnetic radiation
Microwave method
Laser method
Magnetodynamic coupling
Electrical Conduction
Terrestrial transmission line with atmospheric return
Terrestrial single-conductor surface wave transmission line