Vice-President Aristobulo Isturiz announced that civil servants should turn up for work only on Mondays and Tuesdays until the crisis was over.
Venezuela is facing a major drought, which has dramatically reduced water levels at its main hydroelectric dam.
But the opposition has accused the government of mismanaging the crisis.
The measures announced on national television by Mr Isturiz affect two million public sector workers.
"There will be no work in the public sector on Wednesdays, Thursdays and Fridays, except for fundamental and necessary tasks," he said.
Waiting for rain
President Nicolas Maduro had already given most of Venezuela's 2.8 million state employees Fridays off during April and May, to cut down on electricity consumption.
He said Venezuela had been badly hit by the El Nino weather phenomenon and would return to normal when it started raining again.
"We are requesting international help, technical and financial aid to help revert the situation," he said. "We are managing the situation in the best possible way while we wait for the rains to return."
"Several countries in the region have been affected by the drought, caused by El Nino. But Venezuela has the highest domestic consumption of energy."
The government has already adopted a number of other measures to try to deal with the crisis. In February, shopping centres were told to reduce their opening hours and generate their own energy.'
Earlier this week, the government put the clocks forward by half an hour to reduce demand for electricity in the early evening.
Last week, it announced it was introducing power cuts for four hours a day.
The power shortages have deepened the country's serious economic crisis.
Many businessmen and opposition politicians blame the energy crisis and shortages of basic goods on government economic mismanagement.
They say tough currency controls introduced in 2003 by the late president, Hugo Chavez, have only made this worse.
But Venezuela's economy has also been hit by a sharp fall in the price of its main export, oil.