Gas supply to thermal power plants has risen by 6.6% over the past seven months compared to last year, a deputy manager at the Thermal Power Plants Holding Company said.
"Almost all (95.5%) thermal power plants now use natural gas. In 2013 it was half this number," Abdol Rasoul Pishahang was quoted as saying by ILNA.
Although using natural gas as feedstock is a priority in the thermal power stations, reliance on alternative fuels like diesel and mazut is unavoidable in the winter seasons when power plants do not get enough gas due to high consumption of households.
"The cost of burning liquefied fuel instead of natural gas is obviously prohibitive for the thermal power plants," he said, adding that not only is use of eco-unfriendly mazut and diesel detrimental for the environment, it also increases power plants' overhaul costs by up to three times because of technical and associated expenses.
Pishahang said use of mazut and diesel in power plants has decreased by 27% and 21% since March respectively.
Giving a breakdown, he said natural gas, mazut and diesel account for 95.5%, 2.33% and 2.18% of thermal power plants' feedstock.
Thermal units consume an equivalent of 270 million liters of fuel in the summer seasons.
Air pollution has become a major concern in the cold season as power plants use increasing volumes of diesel and mazut. However, the government is moving ahead with programs to substitute liquefied fuels with natural gas in the thermal power plants.
Iran has abundant natural gas deposits and it is more cost-effective to use gas for power generation instead of liquid fuels.
The government has managed to substantially raise gas production, especially from the giant South Pars Gas Field in the Persian Gulf. Close to 198 billion cubic meters of gas is now produced annually from the giant gas field of which 70 bcm is burnt in power stations.
Lengthy, Costly Overhaul
Referring to the number of operating plants, the official said "There are 91thermal complexes generating 80% of the total electricity."
On the need for annual overhaul services, Pishahang said “the operations usually last a total of 270 days and cost $186 million.’
Depending on the type of feedstock, thermal power plant efficiency averages between 20% and 60%, he said.
Power plants which run on natural gas have higher efficiency. According to deputy energy minister, Houshang Falahatian, Iran’s total electricity production capacity is close to 80,000 megawatts, indicating an 11% rise since 2014 when it was about 68,000MW.
The national power grid has expanded by 60,000 kilometers over the past four years and power consumption has risen by 21% in the same period.
Nearly 90% of machinery and equipment needed for power plants is manufactured locally," he said, adding that there are 180 power plants that were built by domestic engineers.
