Feeding thermal power stations with liquefied fuel (mazut) instead of natural gas from Dec 2019 to Feb 2020 is taking a toll on the plants’ overhaul operations, the Energy Ministry spokesman for power department said.
“Unlike in the past when 95% of power plants’ overhaul was implemented before the hot season (May), operations are expected to last one month longer this year,” ILNA quoted Mostafa Rajabi Mashhadi as saying Saturday.
This year maintenance work will take longer and be costlier compared to the past, he added.
Elaborating on technicalities, he said in the 60-day period (Dec-Feb) gas consumption in the household sector soared (at least 25%) and reached 600 million cubic meters per day. As a result, gas delivery to plants was cut and they had to use mazut.
“This (consuming liquefied fuel) reduced efficiency and to make up for the lost efficiency, most stations had to keep generating power and only a few were overhauled.”
Now that power plants have enough gas (feed stock), some of them are being disconnected from the national grid and overhaul operations have started.
Because operations started late, they will end later -- up to June.
Moreover, rehabilitation of plants that burnt mazut will need more funding as machinery and equipment regularly exposed to the eco-unfriendly liquefied fuels become less durable and must be replaced at shorter intervals.
The process of overhaul for all (123) thermal stations cost $500 million in 2019.
Iran Power Plant Repair Company annually carries out overhaul operations on power plants with 12,000 megawatts capacity.
Installed Capacity
According to Mohsen Tarztalab, head of Iran’s Thermal Power Plants Holding Company, effective steps have been taken in recent years to convert conventional plants into combined-cycle units to improve efficiency and cut pollution and costs.
Close to 630 megawatts of electricity was added to the national grid last week at a cost of $860 million and raised overall installed capacity to 83,630 MW.
TPPHC is constructing gas-powered units in Kashan, Urmia, Chabahar, Fars and Qeshm combined cycle power plants. Plans are in place to raise output to more than 85,000 MW by the end of 2020.
An estimated $3.5 billion was invested in power plants in the last two years. Thermal units, which either use steam, gas-powered or combined-cycle turbines, account for 66,000 MW or 80% of total generation of around 84 gigawatts in Iran. Enhancing their efficiency is crucial.
"Steam, gas and combined-cycle units account for 16 GW, 27 GW and 23 GW of the thermal stations, respectively."
Average efficiency of domestic power plants is said to be around 37%. Regarding thermal power generation, Iran is ninth in the world.
