Due to unprecedented low precipitation last winter output from 60 hydroelectric power plants in Iran is projected to decline by at least 30% between June and September compared to a year ago.
The production level which was around 3,200 gigawatt hours last year in the 4-month period is expected to decline to 2,240 GWh, Barq News reported.
The shortfall means added pressure on thermal power stations and/or frequent outages. Hydroelectric plants have an annual output of 10,000 GWh when dams are full, but they produce less because dams are usually half empty.
Production ion from hydroelectric units is designed according to projected water conditions. Increase or decrease in output depends directly on water levels in dams.
Iran registered 126 millimeters of rainfall (208 billion cubic meters of water) between Sept 2020 and March 2021, down by more than half compared to same time a year ago.
Dams across Iran can hold over 50 bcm of water and so far less than 50% are full. The huge deficit in precipitation has resulted in steep decline in water stored in hydroelectric dams, especially in the capital that has nine hydropower plants with 268 MW installed capacity.
Tehran logged 132 mm of precipitation in March 2020, which fell to 2.3 mm in the current fiscal -- a decline unseen in 50 years.
Mohammad Shahriari, head of hydropower facilities at the Tehran Regional Electricity Company, says water in five dams around the sprawling capital is now about 745 billion cubic meters.
Five dams around Tehran, namely Taleqan, Latyan, Mamlou, Amirkabir and Lar can hold 2 bcm of water.
The Amirkabir Hydroelectric Power Plant adjacent to Amirkabir Dam has two 45 MW units, Taleqan Power Station near Taleqan Dam two 8.9 MW units, Latyan Plant close to Latyan Dam two 22.5 MW units and Kalan Power Station in the vicinity of Lar Dam three 38.5 MW units.
Hydropower is a renewable source of energy and is cleaner compared to other sources. It constitutes almost 12,000 MW of Iran’s total installed power generation capacity of 85,000 MW and plays a key role during outages by quickly restoring supply and supporting other plants (mostly thermal).
Water shortages in several regions have become a growing source of serious concern and in Isfahan the sole hydroelectric plant is likely to shut down due to the acute water deficit that has left Zayandehroud Dam with very little water. The dam is situated on the famous Zayandehroud River 10 kilometers east of Chadegan in the key industrial and tourist region in central Iran.
Indigenizing Parts
In related news, IRNA quoted Jalaleddin Hojjati, deputy for operation affairs at the Iran Water and Power Resources Development Company, as saying that engineers have indigenized an important piece of equipment used in hydroelectric power plants.
The automatic voltage regulator (AVR), which is one of the main components in the hydroelectric industry, has been manufactured with domestic knowhow.
AVR regulates voltage during fluctuations and changes voltage into stable power. Fluctuation in voltage occurs mainly due to variation in load on the supply system. Variations in voltage, if huge, often damage power equipment.
“The turbine governor, another major part in power stations, was indigenized recently and is used in Sardasht hydropower station (West Azerbaijan Province) and Daryan hydropower plant (Kermanshah Province).”
Global hydropower capacity reached 1,308 gigawatts in 2019, as 50 countries and territories completed greenfield and upgrade projects, according to the 2020 Hydropower Status Report. A total of 15.6 GW in installed capacity was added in 2019, down from the 21.8 GW in 2018.
China topped the list with 8,540 megawatts, followed by Brazil (3,866 MW), Pakistan (2,487 MW), Turkey (1,085 MW), Angola (668 MW), Tajikistan (605 MW), Ecuador (556 MW), India (535 MW), Norway (419 MW) and Canada (401 MW).
Hydropower is produced in 150 countries because the cost is relatively low making it a competitive source of renewable energy.
