New Delhi: Incessant rains in northern India in the past few days, particularly in the hill states of Uttarakhand and Himachal Pradesh, have disrupted electricity generation due to heavy silt and debris at hydropower projects.
State-owned NHPC Ltd’s 280MW Dhauliganga power project in Uttarakhand has shut down because its power house has gone under water. Power generation at the 394MW Maneri Bhali hydroelectric project in the state too has stopped.
“The power house at Dhauliganga is under water. It is submerged. There is no generation there. Apart from this, there is not much damage,” a power ministry official said, requesting anonymity. “Some projects may be affected due to heavy silt.”
Operations at the 1,500MW Nathpa Jhakri project in Himachal Pradesh, India’s largest hydroelectric plant, have been affected due to high silt content in the turgid and fast-moving Sutlej river.
“It is a usual event. Since the silt load increases, we shut the project down for safety purpose,” said an official at SJVN Ltd’s Nathpa Jhakri project, who, too, declined to be named. The plant can’t be run as the high silt content will damage turbine blades, he said. SJVN is a joint venture between the Union and Himachal Pradesh governments.
Although the early arrival of the monsoon raised hopes that India’s agriculture will benefit during the June-September season, the country has been witnessing one of the heaviest monsoon downpour in recorded history.
India has a power generation capacity of 223,625.60MW, of which 17.7% or 39,623.40MW is hydropower. Of northern India’s installed power generation capacity of 55,885MW, 15,467.75MW comes from hydropower projects. The latest crisis comes at a time when India’s electricity shortage during the peak consumption hours of 8-11am and 6.30-10pm is 8.7%.
Power transmission failures last year, which left 620 million people without electricity, have deepened worries about the country’s ability to meet its rising energy requirements.
India received 112.9 mm of rainfall compared with the typical 72.9 mm, an excess of 55%, in the last 18 days, the Meteorological department said.
On Tuesday, Uttarakhand received 81 mm of rainfall, much higher than the rainfall of 5.4 mm that the state generally receives. In the past 18 days, the state has received 385.1 mm of rainfall, a 440% increase over the normal 71.33 mm.
This isn’t the first time that floods have affected hydropower projects in Uttarakhand. Tehri Hydro Development Corp. Ltd’s (THDC) 400MW Koteshwar power project was affected in 2010.
“The river (Bhagirathi) is no longer in spate. Our project area is safe. Most of the damage has happened where the slopes gave in. Our generation is continuing,” said R.S.T. Sai, chairman and managing director of THDC. “Generation at run-of-the-river projects may be affected because of huge amount of silt and debris.”
Uttarakhand, Himachal Pradesh, Sikkim, Arunachal Pradesh, Meghalaya, Nagaland and Jammu and Kashmir account for a large majority of India’s hydropower potential.
Hydropower projects come with their own set of problems. Executing such projects is a time-consuming and tedious process and their construction requires specialized technology and design.
A majority of state-owned NHPC’s hydropower projects that are under construction have been delayed, Mint reported on 6 May, hampering the government’s bid to increase power generation in order to meet demand and boost economic growth.
The Sikkim earthquake in September 2011 had raised questions on the future of India’s hydropower development. The 18 September earthquake on the Sikkim-Nepal border, which measured 6.8 on the Richter scale, wreaked havoc over a large area.