State Grid Corp of China, the world's largest utility company, also has made rapid moves in its overseas expansion, with several mergers and acquisitions. It has taken stakes in power companies in Brazil, Portugal and Australia in the past two years.

Han Xiaoping, chief information officer of the China Energy Net Consulting Co Ltd, said those overseas M&As can improve the company's profitability by allowing it to enter more foreign markets.

"The Chinese company has advanced transmission technology and management skills, which will greatly help with the local power supply," he said.

In 2011, China Three Gorges Corp, a State-owned power generator, bought about 21 percent of Energias de Portugal SA, a major power company in Portugal.

"The increase in domestic power companies' overseas acquisitions results from China's attempt to institute market reforms in its power sector," said Han.

China's major grids and power generators have been stepping up their foreign expansion by purchasing foreign power companies and investing in local power plants.

CSPG's Deng believes that's wise, as he thinks that electricity exports should not become China's major energy export channel.

"China is a huge economy with growing energy demand for both oil and power. Since electricity is 'derived energy,' which consumes a large quantity of primary energy and imposes environmental costs during its production, it is not a good idea to deliver electricity directly as an energy export," he said.