China's grids would need to be smarter and stronger to accommodate the variability of wind energy

McElroy acknowledges that China's grids would need to be smarter and stronger to accommodate the variability of wind energy. In fact, the Global Wind Energy Council says China's underdeveloped transmission system is already an impediment, delaying the start of energy production from new wind farms. And the group says the problem is becoming more acute as China's wind developments shift to the wind-rich yet remote regions in the north and west, where the grid is weaker than average and power must travel farther to reach consumers. In China's northern autonomous region of Inner Mongolia, grid limits are constraining proposed wind projects, according to Sebastian Meyer, director of research for the Beijing-based consultancy firm Azure International.

Meyer says the challenge will be as much administrative and financial as technical. He says that a political imperative for rural development guarantees that wind power will remain popular among local and regional officials, but how to finance the "smartening and balancing of the grid needs to be resolved." A surcharge of 0.001-0.002 Chinese yuan per kWh that Chinese consumers pay to support integration of renewable energy barely covers the direct cost of patching wind farms into the grids. "Even for this limited end-use, funds have come back to the local grids with considerable delay," says Meyer.

Then again, says McElroy, China is already aggressively upgrading its power grids to link remote hydropower projects with population centers - a process that could expand to distributing massive generation from notoriously unpredictable wind farms. "China certainly has the know-how to build long-distance high-voltage transmission systems," says McElroy.

The major grid upgrades already under way in China are making extensive use of continental-scale high-voltage direct-current (HVDC) lines, which remain the stuff of supergrid blueprints in Europe and the United States. "They are leading the world in implementing long-distance transmission schemes," says Bjarne Andersen, director of U.K.-based consultancy Andersen Power Electronic Solutions.

And Andersen says China's power planners are innovating. An 800-kilovolt HVDC link from central Yunnan province to coastal Guangdong, which will be the world's first when it starts up later this year, is expected to lose 30% less energy in transit than today's 500 kV lines. Several more 800 kV lines are under construction.

The current grid upgrades mirror what would be needed to transmit remote wind power. Most new transmission lines are designed to drive power from western hydroelectric dams toward eastern megacities such as Beijing, Shanghai, and Guangzhou, says Andersen. But there are signs that grid planners are beginning to take wind development seriously as well. Construction began last year on a 750 kV AC line to carry electricity from a wind farm in western Gansu province that is one of six national wind power megaprojects approved by the government.

McElroy says China's political situation may also lend itself to adding the required transmission lines. Wind-rich regions such as the ethnically Uyghur northwest are among China's poorest, and the government has an interest in promoting their economic development. McElroy adds that local opposition, which has stymied transmission projects in North America and Europe for years, is unlikely to stop China's wind power surge. "The government probably has more power to institute a plan once it's approved."

http://www.technologyreview.com/energy/23460/?a=f

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