"There is a world energy crisis, for God's sake, we must understand it! Some people turn on their air conditioners and let them on all night. It's like wasting water day and night," he said.
Chavez said a lack of rainfall to replenish the headwaters of the Caroni River had become "a serious situation that has affected the supply of electricity."
The hydroelectric power station Guri, Venezuela, produces 70 percent of the country's electricity.
"What I mean is that we must all be concerned... everyone has to help save energy," he said.