Since the early onset of winter and increase in home gas consumption, gas supply to power plants has been disrupted as priority shifts to households forcing power plants to use liquid fuel, managing director of Iran's Thermal Power Plants Holding Company said.
“Gas supply to power plants was cut last week and more liquid fuel is being used,” Mohsen Tarztalab was quoted as saying by ISNA.
The main reason is higher demand from households and industries, and if they reduce consumption there will be no need for power stations to use liquid fuel, Tarztalab said.
In the third month of the fall in the Persian calendar (Nov 21-Dec 20), on average 93 million cubic meters of gas, 80 mcm of diesel and 20 mcm of mazut was delivered to power plants every day. However, this volume was cut in the last week of the month to 60 mcm. The outcome was that liquid fuel supply to power stations shot up.
Over the years diesel and mazut use, especially in winter, along with temperature inversion, has had a serious negative impact on air pollution.
Moreover, mazut is not suitable for power plants because it doubles maintenance costs, increases water consumption and decreases output.
Most thermal power plants are natural-gas based and liquefied fuels have long-term adverse effects. Use of diesel and mazut instead of gas in power plants and other industries increases greenhouse gasses.
As more liquid fuel is burnt higher volumes of toxic fumes are released into the atmosphere making a bad pollution situation worse.
When power plants do not receive enough gas they need to either reduce output or burn liquid fuel to avoid outages in regions they provide electricity.
Avoiding Mazut Use
Shazand Thermal Power Plant in Shazand County, Markazi Province, cannot operate at full capacity as it is receiving less gas, managing director of the plant said.
“One of the largest power in the country with installed capacity of 1,300 megawatts, the plant is now operating at half its capacity. We decided to reduce output rather than burn mazut,” Alireza Sheikhi was quoted as saying by Bargh News.
“The decision not to use mazut was taken in accordance with the plant’s policy to help preserve the environment.”
Shazand Power Plant has 4 gas units, each with a capacity to produce 325 MW of electricity. In service for over two decades, it is the only plant in Markazi Province.
To work at full capacity, it needs 8 mcm of gas a day but at present gets half that volume and produces 700 MW, Sheikhi noted, adding that it is still enough to meet the province’s winter need with a population of 1.4 million. Annual production of the plant is seven billion kilowatt hours.
