“To keep old power stations operating is a necessary evil as decommissioning will lead to serious issues in the capital,” Mohsen Tarztalab was quoted as saying by IRNA.
Tarasht Thermal Power Plant west of Tehran and the Rey and Besat stations in the south meet 90% of the total power need in the province, he said.
“Old power plants are saddled with problems namely high water consumption and low efficiency. However, putting them out of service is impossible because doing so will cause chronic outages.”
According to the official, construction of a 230 kilovolt gas-insulated substation has started at the Rey plant as the first step to phase out the 50-year-old station, but building the entire unit needs minimum three years, before which the old units must keep functioning irrespective of their low efficiency.
The three facilities in Tehran have been operating for more than five decades. The estimated useful life of an electricity plant is around 20 years.
Referring to the Rey Plant, he noted that it started working with 40 gas units and generation capacity of 1,200 megawatts. But due to wear and tear and technical problems in some units, only 20 units are operating and output has dropped by half.
The 52-year old Besat station consumes 18 million liters of water per day to produce 1.2 billion kilowatts a year that is 0.4% of the total annual national electricity output which now is 300 billion kWh. Units in the Tarasht facility have an efficiency rate of 20%.
Exponential Growth
Tehran has more than five million subscribers 75% of which are households. At least 100,000 new customers join the subscription list every year that has grown at a regular pace piling pressure on utilities, namely water, electricity and gas.
Tarztalab added that work to overhaul thermal power plants across the country and improve output has started.
“Overhaul of thermal stations is estimated to cost $20 million.”
Thermal plants account for 80% of total power output (84 gigawatts) in the country of 83 million people. Eighty thermal power plants with 65,841 MW capacity are operational, the TPPHC boss added.
THPCC oversees dozens of fossil fuel power plants with installed capacity of over 65,000 MW -- the bulk of Iran's electricity demand. It also is in charge of building 7,000 MW of gas-powered units for the hiraz, Tabriz, Kashan, Urmia and Chabahar combined cycle power plants.