China Space Agency Looks To Capture Sun's Power

Space Agency Looks To Capture Sun's Power

By Stephen Chen [binglin.chen@scmp.com]

Hong Kong South China Morning Post Online in English

Sep 3, 2011

A mainland space agency says the government should build solar power stations in space to solve China's energy problems.

The China Academy of Space Technology, a research institute under the China Aerospace Science and Technology Corporation, said on its website on Thursday that it had submitted a plan to the central government to build a massive facility in space to capture solar power and relay it to earth to generate electricity.

Li Ming, deputy director of the academy, received enthusiastic feedback on the ambitious plan at a conference on Wednesday that included senior officials from the National Development and Reform Commission, the National Energy Administration and other agencies, the statement said.

The mainland is home to the world's largest manufacturing plants of solar panels, and with the bankruptcy of three US manufacturers in the last month, mainland companies now dominate the world supply, accounting for almost three-fifths of total capacity, a report in The New York Times said yesterday.

Economies of scale, low wages and technological advances have enabled Chinese companies to make solar panels cheaply, firing up mainland space scientists' ambitions.

Professor Wang Xiji, a key drafter of the proposal, wrote an article in the Ministry of Science and Technology newspaper Science Times saying that China had built up a solid industrial foundation, acquired sufficient technology and had enough money to carry out the most ambitious space project in history.

Once completed, the solar station, with a capacity of 100MW, would span at least one square kilometre, dwarfing the International Space Station and becoming the biggest man-made object in space, he wrote.

Wang said the solar station would overcome several shortcomings of earth-based plants, such as sensitivity to weather, wasteful land use and a complete shutdown at night. Put in a permanent geostationary orbit, high enough to escape most of the earth's shadow, it would provide a consistent energy supply for 99 per cent of the year.

Wang warned that if it did not act quickly, China would let other countries, in particular theUS and Japan, take the lead and occupy strategically important locations in space.

The US space agency Nasa proposed a solar power station as early as the 1960s, while Japan's Jaxa selected a group of companies and researchers in 2009 to design and build the Space Solar Power System, a massive array of photovoltaic panels, with an anticipated launch date of 2020.

But some scientists said a solar station in space faced technical hurdles that could not be solved by today's technology. The problems include how to lift a large amount of construction materials into space, how to put them together and how to transfer the energy to earth.

Chinese space scientists are considering lasers and microwaves, generating concentrated beams that could travel a long distance with relatively little energy loss. But they have not figured out how to protect people or birds that might get in the way.

Professor Jiang Kaili, a physicist at Tsinghua University, said that in theory wireless energy transmission was possible. Researchers at the Massachusetts Institute of Technology in the US had used strong resonate coupling technology to transfer energy via a magnetic near-field with impressive efficiency.

"The range of transmission reaches a few metres," he said. "It will need to get out of a room before venturing to space."