Mohsen Tarztalab referred to conversion of gas-fired power plants into combined-cycle ones as one of the factors influencing the increase in the efficiency of thermal power stations, the Energy Ministry news website Paven reported.
Noting that the average efficiency of a combined-cycle power station is about 58%, he said the steam unit of some power plants will come online later this year to help increase output and efficiency.
Phasing out ageing power stations with low efficiency is another measure to be carried out by the TPPHC, Tarztalab said, hoping that by the end of the current year (March 2021), efficiency level would reach 39%.
Energy efficiency of a conventional thermal power station, considered salable energy produced as a percent of the heating value of the fuel consumed, is typically 33% to 48%.
Considering all the heat produced by gas and steam turbines, their efficiency is limited and governed by the laws of thermodynamics. Combined-cycle systems, however, have higher levels.
A combined-cycle power plant uses both gas and steam turbines to produce up to 50% more electricity from the same fuel than a traditional simple cycle plant. The waste heat from the gas turbine is sent to nearby steam turbines, which also generate electricity.
“Another way to increase efficiency is to use high-efficiency turbines,” the official was quoted as saying.
Modern turbines, knows as F-class, consume less gas and are more eco-friendly. They help electricity generation in a simple-cycle and combined-cycle power plant rises by 40% and 59%, respectively.
F-class gas turbines are defined by high performance, low power generation costs, long intervals between inspections, and a service-friendly design.
Thermal power stations account for 80% of total power generation in Iran and enhancing the efficiency of such infrastructure at regular intervals is crucial.
Iran has an installed capacity of 84,000 MW. Thermal units, which either use steam, gas or combined-cycle turbines, accounting for 66,000 MW of the total output.
A total of 123 thermal power plants are operational. In thermal power generation Iran is ninth in the world.
Shahrud Plant
Shahrud Thermal Power Plant has increased its output and efficiency to augment electricity supply to the network in the summer seasons, Bargh News reported.
Constructed in 2011, the facility includes two gas units. Each had a capacity of 162 megawatts (overall 324 MW) initially. Now by increasing capacity of each unit to 183 MW, the plant can generate electricity for 80,000 consumers.
Moreover, by improving efficiency from 34% to 36%, nearly 18 million cubic meters of gas needed to generate electricity throughout the year will be saved.
The power plant is located 15 kilometers west of Shahrud, on the road to Damghan in Semnan Province.
Thermal Power Plants Holding Company is the owner of the plant and has plans to add steam units to the station to increase output without consuming more gas and help safeguard the environment.
Natural gas is known as clean fossil fuel, and 95% of power plants in Iran depend on gas to generate power. However, the air is one of the most polluted in the world.
Turning conventional thermal stations into combined-cycle plants can help decrease the amount of greenhouse gas emissions as they emit significantly fewer emissions of carbon dioxide (CO2), sulfur dioxides (SO2), nitrogen oxides (Nox) and other air emissions.