From the Wall Street Journal:
UHV lines may be ideal for bringing electricity from remote areas. All eyes are on a big test in China.
China wants to use melting snow on the Tibetan Plateau to power neon lights more than a thousand miles away in Shanghai. And to make that vision a reality, it is dusting off a 40-year-old technology for moving electricity -- ultra-high-voltage power lines....
...UHV lines can not only carry more electricity than regular lines but also move it vast distances with less loss of power. That makes UHV ideal for bringing electricity from remote areas, such as hydropower projects in the foothills of the Himalayas, to China's eastern urban centers.A number of countries gave the idea a test run decades ago, but improved technology has made it a lot more practical -- and attractive. Now China is betting that UHV can solve its massive energy dilemma. Most of the nation's resources, such as coal and hydropower, are located far from the booming cities that need electricity most. And trucking coal across the country, or building more power plants near cities, would make China's pollution even worse....
...Conventional transmission lines, which use alternating current, can carry up to 500 kilovolts of energy from power plants to substations for distribution. But they're limited in how far they can transmit power, typically up to about 530 miles. And they lose a significant amount of power -- about 7% of capacity -- in transit, requiring power plants to produce more electricity than is used....
...China currently has only one functioning UHV line, a 1,000-kilovolt AC pilot project that represents the highest-voltage system operating commercially anywhere in the world. The line connects two big power grids: one in Shanxi province in northern China, which relies heavily on coal-powered plants, and another in the central province of Hubei, which has abundant hydropower resources, including the Three Gorges dam, the world's biggest. The line enables power to be transferred between the grids whenever there is a shortfall in supply....MORE
Two companies that are almost guaranteed to be involved are Quanta Services (PWR) and General Cable (BGC).
