Electricity Industry   Production A total of 115,708 million megawatt/h energy were generated in the Iranian calendar year 1379 (ending March 2001), showing 7.9% rise compared to a year earlier, 97% of which were produced by the Ministry of Power, and 3% by the private sector. Out of this total amount, 3,650 million kW/h (or 3.2%) were generated by hydraulic plants, 78,332 million kW/h (or 67.7%) by steam plants, 33,365 million kW/h (or 28.8%) by gas-combined cycle plants and the rest by diesel ones.       Consumption A total of 90,366 million kW/h electricity was consumed in 1379 (March 21,2000 to March 21, 2001), indicating 6.7% rise compared to a year earlier. Out of this figure, the highest piece of the pie equaling 34.6% belonged to residential units while 32%, 19.1%. 10.1% and 4.2% respectively belonged to industrial, commercial, public, agricultural units and public passages such as streetlights. Clients Clients The number of clients of the nationwide energy network was less than 16 million (15,570 thousand), 84% of which comprised of residential units, and 6%, 12.1%, 2.9% and 4% belonged to commercial, general (public), industrial and agricultural sectors respectively.   Power Transmission and Distribution Cables In the Nationwide Power Network, the 400 and 230 kW lines are referred to as "Power Transmission Lines" used for transmission of electricity in enormous scale. The length of 400 and 230 kV transmission lines in the country, were 10,157 and 19,883 km/circuit respectively in March 2001, showing 5.5% and 5.1% rise respectively compared to a year earlier. Ultra distribution systems are used to transmit electric power within a city or across the country. They obtain their required power from regional power transmission stations. Voltage of such lines in Iran is either 133 kV or 63 kV (kilo-volts), and seldom 66 kV. The length of 133 and 63 kV lines in March 2001, was 13,429 km/circuit and 29,631 km/circuit respectively, marking 5.9% and 6.2% increase compared to a year earlier. The electricity that ultimately reaches the clients in Iran are generally distributed by ground posts called booster stations that are installed inside special buildings or aerial posts (installed on the top of electric poles). The capacity of such stations in March 2001 was 47,000-megawatt amperes, marking 5.6% increase compared to a year earlier. Export During the Iranian year 1379 a total of 722 million kW/h of electricity was exported to the Republic of Azerbaijan, Turkey and Armenia, indicating 9.5% drop compared to a year earlier.