"The newest technologies used in Maizuru are ready to be transferred to Thailand, because Mitsubishi is now the new partner of Egco," Visit Akaravinak, president of Electricity Generating Plc (Egco), said last week.

Maizuru, which uses bituminous coal as its main fuel, operates under high temperatures to achieve optimum combustion, thus reducing the level of carbon dioxide. Special technology is also employed to lessen the release of nitrogen oxide (Nox), helping to prevent the greenhouse effect, the main cause of global warming.

According to the power plant, the technology could decrease the regulated value of sulphur dioxide (Sox) released into the air to only 49 parts per million and Nox to only 45ppm.

"I have never seen such a low regulated value as this," said Somyos Polachan, senior executive vice president of Egco.

If a coal power plant were constructed in Thailand, 30 per cent of the investment would be spent on environmental protection, he said.

Decharut Sukkumnoed of Kasetsart University said the technologies might curb flue gases as claimed, though he could hardly believe that the full technology would be installed in any power plant constructed in Thailand.

The emission standards for coal power plants are more lackadaisical here. They can emit up to 640ppm of Sox and 350ppm of Nox into the atmosphere, while a biomass-fuelled power plants can emit only 60ppm of Sox and 200ppm of Nox.

Despite the need to seek other fuels besides natural gas, the country has better choices than coal within the next 15 years.

"We have renewable-energy technologies such as biogas, enough to support electricity generation until a more in-depth study on coal power plants is conducted," Decharut said.

An unsolved problem for coal power plants is the high volume of carbon-dioxide emissions, which create the greenhouse effect.

While a natural-gas power plant emits 362-653 grams of carbon dioxide per unit, a coal power plant emits 800-850 grams. Biomass fuel emits 15-101 grams, while wind energy emits only 6-121 grams.

Tara Buakamsri, a climate and energy campaigner for Greenpeace, said half of the mercury released into the atmosphere was emitted by coal power plants.

"In the eyes of the world, Thailand is now recognised as a country mainly using clean energy, so why do we think about stepping backward to a problematic and dirty fuel like coal?" he said.

Tara is unconvinced that a power plant with clean coal technology could be commercially viable here due to its high cost. According to Egco, a coal power plant would cost about US$1.2 million (Bt42.2 million) per MW to build. Bituminous coal has to be imported from Australia, China and Indonesia, and the cost depends on the global market price. "Money would be better spent on a study of renewable technology," he said.

Chatrarat Kaewmorakot

The Nation