Japanese scientists make breakthrough in wireless energy transmission
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