Using reclaimed wastewater and replacing cool towers with dry towers has helped Hamedan’s Shahid Mofateh Thermal Power Plant to curb water withdrawal from ground resources by 85%, managing director of the company said.
“As per a directive by the Energy Ministry, it is obligatory for all thermal power plants to use processed wastewater [instead of potable water] in the cooling towers,” Abdulmajid Dinarvand was quoted as saying by Barq News.
On the long-term plans to replace water from wells, lakes and rivers in power plants with treated wastewater, he said the first project to supply treated wastewater to cooling towers is being implemented in SMTPP.
Hamedan Regional Water Company and Bakhtar Regional Electricity Company, a subsidiary of government-affiliated Power Generation, Distribution and Transmission Company (Tavanir), have signed a contract according to which the latter (the regional power company) will receive 15 million cubic meters of water annually.
Despite difficulties, including lack of special pipes and the task of convincing rigid farmers to lay water pipes in their farms, 60 kilometers of pipes were laid to transfer treated sewage from the water company to the power station.
Similar plans are being implemented in other plants namely Ramin thermal power plant in Ahvaz in southwest Khuzestan Province and Isfahan Power Plant in the eponymous central province.
"Reducing water consumption is a compulsion, more so because for years Iran is grappling with disappearing underground water tables."
Priority Issue
According to the official, using treated wastewater in thermal power stations with wet cooling towers will have priority over those with dry cooling towers.
In the drought-hit central plateau including Isfahan and Yazd long suffering from chronic water deficits, wet towers will be replaced with dry towers in the long run because of the latter’s ability to cut water consumption by at least 40%.
Wet towers have high cooling capacity. However, due to high water consumption their use in arid regions saddled with water crisis 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 that decreased water consumption from 3 mcm to 600,000 cubic meters. Work is in progress on the second dry cooling tower and it is expected to come online in 2021.
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 and 4 units. The first was commissioned in 1995 and the last in 1997.
Illegal Wells
In related news, Energy Ministry’s news portal quoted Mansour Sotoudeh, managing director of the provincial water company, as saying that of the 7,000 illegal wells in the province 4,000 were sealed in the past five years.
“Sealing the wells saved 300 million cubic meters of water.”
The move has helped maintain a semblance of stability in groundwater levels in the region that has been falling sharply.
Almost 4,447 smart meters have been installed on authorized water wells in the northwestern province. The agriculture sector accounts for 75% of the new digital meters.
Smart meters have also been installed in rural homes (10%), urban households (6%), industries (6%), livestock and poultry sector (3%) and miscellaneous (1%).
