Dezhou City, in the east China's Shandong Province, will host the Fourth International Solar Cities Congress in September 2010.

The location was chosen because it is China's first and only "Solar City".

Dezhou is installing solar heaters on 1 million roofs, Dezhou mayor Wu Cuiyun said on Friday.

The low-tech devices capture the sun's energy heating water used for bathing or washing.

So far, more than 100 villages in the city had set up solar energy bathhouses. The figure is expected to rise to 1,000 by 2010, Wu said.

The green technology is growing in popularity. About 200 million Chinese people will be using solar energy water heaters, over an area of about 150 million square meters, up from current 100 million square meters by 2010, said Huang Ming, board chairmanof Dezhou-based Himin Solar Energy Group, China's top maker of solar water heaters.

Compared with wind power generation and solar panels used to generate electricity, solar heaters are cheaper.

They cost no more than 0.2 yuan (less than a US cent) for each kilowatt hour of electricity. Its use has been spreading fastin China's urban and rural areas, Huang said

"China accounts for around 76 percent of the world market of solar heaters. The potential domestic market is huge," Wu said.

China follows the Republic of Korea, Britain and Australia to host the international solar congress. More than 1,000 representatives from 40 countries have applied to attend its forums, panel discussions and fairs.

The main venue for the event in Dezhou will be a 60,000-square-meter micro-emission building.

(Xinhua News Agency January 10, 2009)