"As per a directive issued by the Energy Ministry, it is mandatory for all thermal power plants to use reclaimed wastewater [instead of potable water] in their cooling towers," Paven, the ministry's news portal quoted Abdolrasoul Pishahang as saying.
Elaborating on long-term plans to replace water taken from wells, lakes and rivers in power plants with reclaimed wastewater, he said," The first treated wastewater project to supply water to the cooling towers is currently being piloted in SMTPP."
Hamedan Regional Water Company and Bakhtar Regional Electricity Company, a subsidiary of government-affiliated Power Generation, Distribution and Transmission Company (Tavanir), signed a $5 million contract in 2015 according to which the former receives 15 million cubic meters of water a year, according to Financial Tribune.
"Curbing water consumption is a compulsion, more so because for years Iran is grappling with disappearing underground water tables."
According to Pishahang, using treated wastewater in thermal power stations with wet cooling towers will be given priority over those with dry cooling towers.
In the drought-hit central plateau including Isfahan and Yazd long suffering from huge water deficits, wet towers should be replaced with dry towers in long run because the latter help cut water consumption by at least 30%.
Wet cooling towers have a high cooling capacity. However, owing to consumption of large quantities of water, their use in arid regions struggling with water crisis can cause operational problems. In dry cooling towers there is no direct contact between the working fluid and the ambient air, so there is no water loss in the process.
One dry cooling tower went on stream in SMTPP in 2015 which decreased the power plant's water consumption from 3 mcm to 600,000 cubic meters. In other words, so far it has saved 2 mcm of water per annum.
Ramin thermal power plant in Ahvaz in southwest Khuzestan Province and Isfahan Power Plant in the eponymous central province will soon be supplied with treated wastewater for cooling towers.
A total of 123 thermal power plants are operational with nominal capacity to produce 65,000 megawatts of electricity.
Iran has an installed capacity of 81,000 MW and plans to raise output to more than 85,000 MW by the end of the year.
SMTPP is located at 47 km northeast of Hamadan. Its infrastructure is of the TYPE Oil Power Plant with a design capacity of 1000 MW. It has 4 units. The first was commissioned in 1995 and the last in 1997.
UNESCO 2017 World Water Development Report says once treated, wastewater could be invaluable in meeting growing demand for freshwater and other raw materials.
Environmentalists and experts say industries can and must use recycled water for heating and cooling instead of the scarce and costly potable water.
Reports say 216 wastewater treatment plants are operating in Iran with an annual output of 1.2 billion plus cubic meters of reclaimed wastewater.
Treated sewage mostly goes for agriculture (57%), and the rest is consumed in industries, urban green spaces and replenishment of surface waters and groundwater resources.
Almost 70% of water consumed in households turns into sewage.