The city launched a campaign to reduce sulfur discharge from its power plants yesterday, with the aim of slashing sulfur pollution by two-thirds before the end of 2010, the Shanghai Environmental Protection Bureau announced yesterday.

All coal-fired generators will have to install desulfurization equipment to cut pollution, although that will push up the cost of power generation.

After a lengthy feasibility study, authorities have worked out a preliminary five-year plan with power companies on how the plan will be enforced.

"We are now determined to get down to the problem for a city that is heavily reliant on coal-produced electricity," said Wang Jue, vice chief of the bureau's pollution control division.

The city has 16 coal-fired power plants. With a total capacity of more than 10.6 million kilowatts, they account for more than 90 percent of Shanghai's total generating capacity. The remaining 10 percent of the city's locally produced power is generated by gas, oil and wind.

While several of the coal-fired power plants in the city have already installed the desulfurization equipment, they still discharge nearly 300,000 tons of sulfur dioxide into the air each year.

The sulfur pollution could cause acid rain, and "has had a considerable influence on the city's air quality," according to a statement from the bureau. It didn't state specifically what influence the sulfur has had on the city's air.

To encourage the power companies to take part, the city government will offer some financial subsidies to cover the cost of installing and using the new equipment.

The equipment is expected to cost 400 yuan (US$49) for every 1,000 watts of generating capacity.

The total investment in the project will be around 4 billion yuan by 2010.