China considering space-based solar power station
The project, which is still in the conceptual stage, would involve a satellite that weighs more than 10,000 lbs., dwarfing anything previously placed into orbit, including the International Space Station, according to the China-based Xinhuanet, part of the Xinhua News Agency.
While space-based solar power is not a new idea, some Chinese scientists believe a collector could be launched as soon as 2020, although others place the launch date further out, as far away 2050.
"China will build a space station in around 2020, which will open an opportunity to develop space solar power technology," Li Ming, vice president of the China Academy of Space Technology, was quoted as saying to the Xinhuan news agency.
Members of the both the Chinese Academy of Sciences (CAS) and the Chinese Academy of Engineering (CAE) wrote a report five years ago that suggested China should begin with an experimental space-based solar power station by 2030, and build a commercially viable space power station by 2050.
Wang Xiji, of the CAS and a member of the International Academy of Astronautics, said building a solar space station is feasible, although it would be an unprecedented and monumental task.
Xiji said a solar space station in a geosynchronous orbit could circumvent the problem with intermittent energy production on Earth, which must contend with nighttime and weather interruptions.
Duan Baoyan, a member of the CAE, said space-based solar panels could generate 10 times as much electricity as ground-based panels.
There are tremendous obstacles to not only building and launching a solar space station, but also in getting the power it would generate back to Earth.
"An economically viable space power station would be really huge, with the total area of the solar panels reaching five to six square kilometers," Xiji said.
Six square kilometers is nearly twice the size of New York's Central Park.
If the massive solar collector could be placed into orbit, scientists in China believe the energy produced could be beamed back to Earth via microwave or laser, but that would require at least a 50% efficiency rating in order for it to be economically viable.
As farfetched as the massive power space station may seem at first, both the U.S. and Japan have also been working on systems that could beam power back to Earth.
The Japan Aerospace Exploration Agency (JAXA) has proposed its own solar collector to be launched within the next 25 years.
Last month, JAXA demonstrated wireless microwave transmission of solar power in space by beaming 1.8 kilowatts of electricity via microwave transmission 55 meters to a pinpoint target on a receiver.
In the late 1970s and 1980s, the U.S. Department of Energy and NASA jointly investigated the concept of space-based solar power under the Satellite Power System Concept Development and Evaluation Program. In 1999, the Space Solar Power Exploratory Research and Technology program (SERT) was created by NASA to study the feasibility, design, and requirements of space-based solar power.
"When space solar energy becomes our main energy, people will no longer worry about smog or the greenhouse effect," Xiji said.