Operations to replace old steam units with new gas units in Tarasht Power Plant in Tehran are on track and expected to be completed by the end of the current Iranian year (March 2024), the plant’s deputy for planning and engineering said.
“According to the plan, six new gas units, with a nominal capacity of 9.8 megawatts each, will replace the old steam units with massive water consumption,” Amir Hossein Hassan Ahi was also quoted as saying by the Energy Ministry’s news service.
The renovation of the facility will double its efficiency from 25% to 50%, he said, noting that in the 1990s, the power plant met more than 50% of Tehran's electricity needs.
Established in the 1930s with four steam units and a wet cooling tower, Tarasht Power Plant has a nominal capacity of 60 megawatts.
Based on international standards, the average useful life of such plants is 25 years. This is while the power plant is over 60 years old.
In addition to being outdated, another problem with Tarasht was that it had a wet cooling tower that is preferred in regions where water is plentiful, like the coastal regions.
In wet cooling towers, heat transfer is measured by a decline in processing temperature and a corresponding increase in both the moisture content and the wet bulb temperature of the air passing through the cooling tower.
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 implies minimal water loss.
When the facility opened over half a century ago, Tehran was not struggling with chronic water scarcity. But conditions have changed and the population has jumped from 3 million then to over 10 million at present.
Low Efficiency
According to Mohsen Tarztalab, former managing director of Thermal Power Plants Holding Company, decommissioning outdated thermal power plants is a compulsion, because despite consuming more natural gas as feedstock, their efficiency is as low as 25%.
As long as the government and private sector do not invest in the key sector, modern power stations cannot become operational and demand will surpass supply, he added.
“If the government settles its debt to TPPHC, we will be able to pay off our debts to private sector contractors and they will be willing to embark on new initiatives,” he said.
“The number of projects held up by financial constraints is on the rise, meaning the gap between production and demand is increasing day by day.”
Energy officials in Iran Power Generation, Distribution and Transmission Company have suggested boosting electricity imports from neighboring states to meet domestic demand.
The former TPPHC chief says, “The Energy Ministry has enough money for purchasing power from other countries, but it does not have the budget to settle our debts. If the Energy Ministry had remained committed to its financial obligations, the private sector would have been able to help meet all the needs and Iran could have become a power exporter and not an importer.”
