The modest and quietly spoken chairman and chief executive officer of LDK Solar, one of China's leading solar energy companies, insists sun power will eclipse coal, gas and oil in the 22nd century.

One of China's leading young entrepreneurs and listed by Forbes magazine as one of the 500 richest men in the world, he believes people consistently underrate this natural form of new energy.

China's solar power usage currently barely registers above zero as a percentage of total energy sources.

"In 100 years, my view is that 60 percent of the world's energy will come from solar power," he said.

"This is not an optimistic prediction. The European PhotoVoltaic Industry Association (one of the solar energy industry's main trade bodies) puts the figure at 80 percent."

Because of their current marginal status, it is all too easy to dismiss new energy sources as something of a sideshow to ease climate change fears.

Renewable energy target

The Chinese government, however, wants 20 percent of the country's power to be from renewable energy (of which hydro will be a major part) by 2020.

Peng insists people fail to realize existing energy sources, oil in particular, are going to run out.

"Oil, maybe, has 50 years, I don't know. That is because it is not very renewable. It is also going to get more expensive. Even with the background of a financial crisis like now, its price has gone back up to $81 a barrel," he said.

LDK has had something of a torrid time itself recently. Its shares on the New York Stock Exchange initially soared to nearly $70 from their initial flotation price of $27 in 2007 but have since slumped to just a tenth of their peak value at around $7.

With Peng owning around 70 percent of the equity of the company, this has put a considerable dent in his personal fortune, although he still retains major private interests.

In December, the company went back to the NYSE and has raised a further $122 million, using around $90 million of the proceeds to pay back short-term debt as well as develop other aspects of the business.

"The economic crisis has affected everybody and, in particular, solar energy. Many projects have been delayed, mainly because of the problems in getting bank finance," he said.