EghtesadOnline: The average volume of water used to produce electricity in Besat Combined-Cycle Power Plant in south Tehran is 45 times above other power stations in the capital.
According to Barq News, the 52-year old facility consumes a whopping 18 million liters of water per day (18,000 cubic meters/d) to generate 1.2 billion kilowatt a year, accounting for a paltry 0.4% of the total annual national electricity output which now is 300 billion kWh.
The rapidly depleting water is extracted from six deep water wells as water shortages continue to pose a serious risk to the overcrowded capital.
The ageing plant uses as much water as 70,000 people in the capital consume in a day. Per capita water consumption in Tehran is 250 liters a day.
Drawing parallels between (state-run) Besat Plant and the privately-owned Damavand Combined Cycle Power Plant in southeast Tehran, the news portal said water consumption in the latter is 400 cubic meters a day and its output is nine times over and above the former.
Based on data from Iran Power Generation, Distribution and Transmission Company (Tavanir), efficiency of Besat Power Station is less than 30% but it annually uses at least 500 million cubic meters of gas as feedstock.
The estimated useful life of an electricity plant is 20 years. In addition to being outdated, the problem with Besat is that it has a wet cooling tower that is preferred in regions where water is plentiful, like the coastal regions.
Seemingly, when the facility started work 50 years ago, Tehran was not struggling with water scarcity. But now conditions have changed as the population has exploded from three million to ten million and decommissioning decrepit plants should be a priority, the website added.
In wet cooling towers, heat transfer is measured by decrease in the process 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 means that minimal water loss is achieved.
Iran’s Thermal Power Plants Holding Company has warned that if rehabilitating the ageing plants is delayed, maintenance costs will become prohibitive for the highly subsidized and apparently loss-making energy sector.
Besat has a capacity of 200 megawatts -- a small part of the 3,000 MW Tehran needs. Other power plants in Tehran are Tarasht in the west and Rey in the south which have a capacity of 800 MW and 65 MW, respectively.
Water Levels Falling
In related news, IRNA quoted Ahmad Ali Qorbanian, the deputy for operations at the Tehran Regional Water Company, as saying that wells in and around Tehran are in bad condition with water levels falling regularly. Experts have often warned that the situation will not improve with good rainfall in one or two years.
Unsustainable and unacceptably high consumption are taking a high toll and threatening water supplies in the capital that is home to more than ten million people. The situation in other parts of the country is no better.
The steep decline in groundwater levels is having devastating consequences. Excessive pumping is harming groundwater tables and stopping wells from reaching the groundwater. When groundwater is overused, lakes, streams and rivers connected to groundwater also start diminishing and vanish as time passes.
Groundwater overdraft can also lead to land subsidence as it occurs when there is loss support below the ground.