Main roads to Buenos Aires have been blocked by people protesting against power cuts and demanding government action on shortages affecting many parts of the Argentine capital.
Residents set fire to rubbish bags and tyres on the roads on Monday, causing long traffic jams as many left the capital for the New Year festivities, the BBC reports.
Authorities are blaming the energy crisis on the country's worst heatwave in decades, with temperatures over 38 degrees Celsius recorded.
Some neighbourhoods have been without power for two weeks, with a marked increase in the use of air conditioning.
Buenos Aires mayor Mauricio Macri says President Cristina Fernandez de Kirchner should change the time zone in the east of Argentina - where Buenos Aires is - to save energy.
Mr Macri said the private energy suppliers cannot take all the blame for the crisis.
"Private companies are also responsible, but the main responsibility is with the federal government. The government must control to make sure there is an investment programme, which has not happened in the last decade. And now we are regretting the consequences of that."
Argentina's ageing power grid has been struggling to keep up with demand.