The construction of the new power station at the site of the aging Besat Power Plant in southern Tehran is complete and awaiting the permission of the Department of Environment to start operations, following which the aging plant will be decommissioned, a deputy manager at Iran's Thermal Power Plants Holding Company.
“Decommissioning aging power plants and replacing them with modern ones that have higher efficiency are aimed at producing more electricity with less fuel,” Nasser Eskandari was also quoted as saying by ISNA.
Besat Power Plant is 53 years old. When it was built in 1968, its efficiency rate was 34% but is now below 30%.
Although it is possible to make some improvement through repair and maintenance, efficiency will not exceed the initial 34%.
This is while “the current efficiency of power plants is 39.1%,” Eskandari said.
“As per the plans, we will increase the figure to 39.2% by the end of the current Iranian year [March 2024].”
A new gas turbine (MGT-75), which has been manufactured by Iranian engineers, has been installed at Besat and when it becomes operational, one aging turbine in the facility will stop working.
The new turbine will almost double the efficiency of the plant and increase production from 160 megawatts to 200 MW.
Based on data from Iran Power Generation, Distribution and Transmission Company, the plant annually uses 500 million cubic meters of gas as feedstock. The new turbine will cut this by half.
One specific feature of the MGT-75 turbine is that not only does it run on gas, but can also use hydrogen as feedstock.
Benefiting from hydrogen in megacities like Tehran is crucial, as the metropolis has been suffering from air pollution forever.
Adding hydrogen to natural gas is a major step toward decarbonization, as its combustion process emits less greenhouse gases, including CO2, and produces more energy.
Water Consumption
The Besat facility consumes 18 million liters of water per day (18,000 cubic meters/d) to generate 1.2 billion kilowatts a year.
Rapidly depleting water resources are extracted from six deep wells, as water shortages continue to pose a serious risk to the overcrowded capital.
The aging plant uses the equivalent of water used by 72,000 people in the capital in one day. Per capita water consumption in Tehran is 250 liters per day. The new turbine will cut water consumption to less than 800,000 liters a day.
The estimated useful life of a power plant is 20 years. In addition to being outdated, another problem with Besat is that it has a wet cooling tower that is preferred in regions where water is plentiful, like the coastal regions.
In areas like Tehran where access to water is limited, dry cooling techniques are used. As the name suggests, this relies on air as the medium of heat transfer, rather than evaporation from the condenser circuit. Dry cooling means minimal water loss is achieved.
When the facility opened half a century ago, Tehran was not struggling with chronic water scarcity. But conditions have changed and the population has jumped from three million then to more than 10 million at present.
Eskandari noted that in addition to scrapping old power plants, there are plans to add steam units to the thermal power plants and convert them into combined cycle stations.
Regarding the overhaul of power plants, the official said 97% of the repair programs have been completed and the rest will be done in the coming days.
“More than $160 million have been spent on the repair and maintenance of power plants,” he said.
The overhaul program started last September and will continue until June.
Eskandari said 69% of the power plants in the country are owned by the private sector and 31% are owned by the state, and all repair operations are carried out by TPPHC.
