The power ministry cautioned states as early as 18 August about depleted coal stocks failing to match the sharp increase in electricity demand. The warning bells were twinned with a request to clear their pending fuel and transportation dues, according to government documents reviewed by Mint.

Some of these are West Bengal, Maharashtra, Rajasthan and Andhra Pradesh. The coal stock available at power plants at the time had reached 18.5 million tonnes (mt), sufficient for only nine days of generation.

In its communication to Maharashtra chief secretary Sitaram Kunte, Union power secretary Alok Kumar wrote, “As you are aware, we are witnessing a sharp increase in demand for electricity as the economy is opening up. As coal-based thermal power plants (TPP) share most of the power demand, states need to ensure there is sufficient coal stock available at power stations."

This followed a revival in peak electricity demand, which had dropped during the second wave of covid-19 infections. According to Central Electricity Authority (CEA), as of Tuesday, India’s 119 coal-fuelled power projects totaling 129.866 gigawatts (GW) capacity had four days of stocks. Another 16 plants located near coal mines totalling 35.2GW capacity had five days of stock. This assumes importance given that coal-fuelled capacity contributes 52.41% or 202.80GW of the installed power generation capacity of 386.88GW. “There are also legacy issues of heavy dues of coal companies from certain states viz., Maharashtra, Rajasthan, Tamil Nadu, UP, Rajasthan and Madhya Pradesh," the ministry said in a 9 October statement.

“In this regard, I would like to inform you that the coal stock at TPPs is depleting at a fast rate. As of 15.08.2021, the average coal stock available in the country at plant level was 18.5 mt, which is sufficient for only 09 days. This is a matter of concern," the letter to Kunte added.

According to the power ministry, as of 31 July, Maharashtra State Power Generation Co. Ltd’s (Mahagenco) dues towards coal companies and railways was ₹2,615 crore. “Looking at the critical coal stocks, I would again request you to direct Mahagenco to clear the outstanding dues of coal companies in a time-bound manner so that there is no regulation of coal supply from CIL end," additional secretary in power ministry Vivek Kumar Dewangan wrote to Maharashtra principal secretary, energy, Dinesh Wagmare on 9 September.

Queries emailed to a power ministry spokesperson on Wednesday remained unanswered. Spokespersons of the governments of West Bengal, Maharashtra, Rajasthan and Andhra Pradesh could not be contacted immediately.

“Power System Operation Corporation Ltd has reported that the total capacity of units under outage due to low coal stocks has reduced from 11GW on 12 Oct to 6GW on 13 October," Union power ministry said in a note late Wednesday.