In his annual state of the nation address on Wednesday, Nazarbayev -- in power since before the 1991 Soviet collapse -- said it was time for Kazakhs to get rid of their wasteful habits.

"You've all been abroad and you know how they treat electric power there, even in the richest countries," he said.

"If we continue like this, all the existing electric power stations will stop working and upgrading their equipment. A four-people family living in a three-room apartment can set up electric meters and save up to 40 percent of energy."

Living standards in Kazakhstan, a nation roughly the size of Western Europe but populated by only 15 million people, have improved dramatically over past years due to booming revenues from its key oil and metals exports.

It is home to some of the world's biggest energy deposits and has drawn billions of dollars of foreign investment since its independence from the Soviet Union in 1991.

Luxury cars and ritzy shopping malls have become the norm of daily live in Almaty and Astana, its key cities.

But, in a legacy of Soviet times, people still pay minimal utilities fees as the industry remains heavily subsidised. Many leave the lights switched on round the clock and do little to save water in one of the world's driest regions.

In the industrial north where Soviet-era production sites belch plumes of toxic emissions into the air every day, green ways have also yet to take off. Air pollution is a major problem in the financial capital Almaty due to automobile emissions.

Nazarbayev said the industry ought to raise prices gradually to be able to invest in better, more energy-efficient equipment.