Siemens is bringing electricity to the surface from the world's deepest arch-dam turbines. The dam of the Jinping-1 Hydropower Station in China's Sichuan province is 305 meters tall; the turbines are located 230 meters deep. The facility will have a total power output of 3.6GW. In order to transport this huge amount of energy up out of the mountain, Yalong Hydro is using gas-insulated transmission lines (GIL) from Siemens. This technology is especially well suited for the transmission of large amounts of electricity in restricted spaces.
Gas-insulated tubular lines can transmit up to 5kA at up to 550 kilovolts (kV). Every line consists of two concentric aluminum tubes. The space between the inner conductor and the earthed outer tube is filled with insulating gas. GIL systems not only transmit huge amounts of electricity in very restricted spaces, they are also fireproof; unlike standard power cables. As a result, GILs are a safe and easy-to-install solution for the transmission of electricity out of underground power stations or tunnels. The Jinping-I transmission line consists of a total of three parallel GIL systems, each of which has three mono-polar tubular lines that lead vertically up at the dam.
