Energy-hungry China warms to solar water heaters

DEZHOU, China, June 4 (Reuters) Dusty Dezhou was relegated to the footnotes of Chinese history for centuries, known mainly as the place where a Filipino king died.

Now, Huang Ming hopes hot water will help put it on the map.

His company has earned a fortune manufacturing solar heaters, relatively low-tech rooftop devices which capture the sun's energy to provide water for baths and washing and are at the forefront of a renewable energy drive.

At least 30 million Chinese households now have one and last year the country accounted for around 80 per cent of the world market, said Eric Martinot, visiting scholar at Beijing's Tsinghua University. ''We are at 15 to 20 per cent annual growth and I don't see that slowing down.'' Huang says his Dezhou-based firm, China Himin Solar Energy Group, is the largest in a fragmented and almost entirely Chinese market, with a share of around 14 per cent.

And the mayor is using his heating success as the basis for a a bid to follow British University town Oxford and Australia's Adelaide as host of an international solar congress.

Cheap and effective enough to make economic sense to middle-class urbanites, Huang's basic models start at around 1,500 yuan, although for a luxury home this could rise to 18,000 yuan.

With technology so efficient they can work at temperatures well below freezing and under cloudy or smog-choked skies, they soon pay for themselves, he says.

''Even in winter when the temperature is minus 20, and with this kind of pollution, they can produce hot water,'' Huang says, gesturing to the city's grey skies.

Demand from house-buyers is forcing many builders to include the heaters in new blocks, and a government pledge that all buildings in major cities will be revamped to make them more energy efficient by 2020 should mean further customers.

Wind power generation, or more familiar solar panels used to generate electricity, are expensive and usually need government subsidies to take off. The heaters have spread far faster.

HEAT IN COLDEST WEATHER All have the same basic design, a row of sunlight-capturing glass pipes angled below an insulated water tank.

The key to the demand boom, even in the freezing northeast and chilly western deserts, is the vacuum separating the inner tube with its energy-trapping coating from an outer tube.

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