The shortage happened as the surging number of Covid-19 cases in Vietnam caused a shortage of minters at state-run Vinacomin, the biggest coal mining company in the country, according to the government news portal.
Vietnam recorded over 273,400 new Covid-19 cases on average in each of the last even days.
Another reason given is the global rise in coal prices and difficulties in delivery due to the Russia-Ukraine crisis.
On the global market, coal prices reached a 14-year high of US$401 per ton in early March, driven by the effect of the Russia-Ukraine conflict on supply.
The Ministry of Industry and Trade has asked Vinacomin and another coal supplier, Dong Bac, to ensure that there is no coal shortage in any circumstances.
Last year, Vinacomin supplied nearly 16.2 million tonnes of coal to Vietnam Electricity (EVN) plants, and the figure is set to rise to 18.08 million this year.
Coal-fired plants accounted for 43.6 percent of total power generation in February, according to EVN.