Japanese scientists make breakthrough in wireless energy transmission - remember TESLA? - JAXA Science Article

A solar flare erupts on the Sun's northeastern hemisphere during a powerful solar storm in January 2012. Japanese scientists have succeeded in transmitting energy wirelessly, a key step that could one day make solar power generation in space a possibility, an official said this week. | NASA / AP

NATIONAL / SCIENCE & HEALTH

Japanese scientists make breakthrough in wireless energy transmission

AFP-JIJI, JIJI

• MAR 13, 2015
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Japanese scientists have succeeded in transmitting energy wirelessly, a key step that could one day make solar power generation in space a possibility, an official said.

Researchers used microwaves to deliver 1.8 kilowatts — enough to run an electric kettle — through the air with pinpoint accuracy to a receiver 55 meters (170 feet) away.

While it wasn’t a great distance, the technology could pave the way for mankind to eventually tap the vast amount of solar energy available in space and use it here on Earth, a spokesman for The Japan Aerospace Exploration Agency (JAXA) said Thursday.

“This was the first time anyone has managed to send a high output of nearly 2 kilowatts of electric power via microwaves to a small target, using a delicate directivity control device,” he said.

JAXA has been working to devise space solar power systems, or SSPSs, for years, he said. Solar power generation in space offers many advantages, notably the permanent availability of energy regardless of weather or time of day.

While man-made satellites, such as the International Space Station, have long been able to use the solar energy that washes over them from the sun, getting that power down to Earth where people can use it has been a thing of science fiction.

But the Japanese breakthrough offers the possibility that humans will one day be able to tap an inexhaustible source of energy in space.

The idea, said the JAXA official, would be for microwave-transmitting satellites with sunlight-gathering panels and antennae to be set up about 36,000 km (22,300 miles) from Earth.

“But it could take decades before we see practical application of the technology — maybe in the 2040s or later,” he said.

“There are a number of challenges to overcome, such as how to send huge structures into space, how to construct them and how to maintain them,” he said.

The SSPS concept emerged in the U.S. in the 1960s. Japan’s version, mostly financed by the industry ministry, started in 2009, he said.

Resource-poor Japan has to import huge amounts of fossil fuel. It has become substantially more dependent on these imports as its nuclear power industry shut down in the aftermath of the disaster at Fukushima in 2011

Mitsubishi Heavy Industries Ltd. meanwhile said Thursday it succeeded in transmitting 10 kilowatts wirelessly to a receiver 500 meters away, in a test in Kobe. It hopes to find practical applications for the technology in five years, such as for charging electric vehicles or powering warning lights on power transmission towers. The company also said it aims to use the technology to send power to isolated areas in the wake of disasters.

Mitsubishi Heavy has cut costs by using a mechanism employed in microwave ovens because the cost of wireless power transmission technology used in space is high, according to the company. The company plans to eventually halve the cost.

At present, a more efficient system is needed to transmit power from offshore wind turbines and send electricity to isolated rural areas, Mitsubishi Heavy said

Mobile phones - charged by the power of music, noise or speech

Mobile phones could be charged by the power of speech

Mobile phones could soon be charged by simply speaking into the handset.

Engineers have developed a new technique for turning sound into electricity, allowing a mobile to be powered up while its user holds a conversation Photo: ALAMY

By Richard Gray, Science Correspondent

10:00AM BST 08 May 2011

29 Comments

For mobile phone users, a flat battery or a lost charger are among the frustrations of modern life.

Now new research promises a way to recharge phones using nothing but the power of the human voice.

Electrical engineers have developed a new technique for turning sound into electricity, allowing a mobile to be powered up while its user holds a conversation.

The technology would also be able to harness background noise and even music to charge a phone while it is not in use.

However, there could be a downside to the innovation, if it gives people a new reason to shout into their phones as they attempt to squeeze in every extra bit of power they can.

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Dr Sang-Woo Kim, who has been developing the design at the institute of nanotechnology at Sungkyunkwan University in Seoul, South Korea, said: "A number of approaches for scavenging energy from environments have been intensively explored.

"The sound that always exists in our everyday life and environments has been overlooked as a source. This motivated us to realise power generation by turning sound energy from speech, music or noise into electrical power.

"Sound power can be used for various novel applications including cellular phones that can be charged during conversations and sound-insulating walls near highways that generate electricity from the sound of passing vehicles.

"The latter development would have the additional benefit of reducing noise levels near highways by absorbing the sound energy of vehicles."

The technology uses tiny strands of zinc oxide sandwiched between two electrodes. A sound absorbing pad on top vibrates when sound waves hit it, causing the tiny zinc oxide wires to compress and release. This movement generates an electrical current that can then be used to charge a battery.

A prototype of the technology was able to convert sound of around 100 decibels - the equivalent of noisy traffic - to generate 50 millivolts of electricity.

"This is not enough to charge a phone properly, but Dr Kim and his colleagues hope that by altering the material the wires are made from they will be able to produce more energy at lower sounds levels.

He said: "Our current output performance can be applied to various electronic devices with low-power consumption such as self-powered sensors and body-implantable tiny devices. We believe that we can realise more efficient sound-driven nanogenerators."

Researchers and some manufacturers have already started looking at using 'energy scavenging' as a way of powering portable electronic devices.

Scientists have developed devices that can use the heartbeat to power MP3 players, while Nokia has filed a patent for a device which harvests energy from movement, much like a kinetic energy powered watch.