So then the utility complained that it would cost $260 million a power plant to install enough scrubbers, leading to skyrocketing electric costs.

In 2004, Duke Energy began installing scrubbers, which will lower the station's sulfur dioxide emissions by approximately 95 percent.

Utilities can install scrubbers to filter their smoke, but the scrubbers cost $100 million or more, so few have.

If prices remained at that level, utilities might be encouraged to buy credits rather than to install pollution control devices, or scrubbers, experts have said.

Increased rates to consumers still are inevitable; but they should be less than if all polluters were required to install scrubbers.

The options include installing scrubbers on coal-fired units and switching fuels.

More recently, the Government has ordered the region's iron foundries to install scrubbers and filters on their smokestacks.

"If the users go to the expense of installing scrubbers in their power plants."

By installing scrubbers that captured the sulfur, companies could free the allowances they were given, and then sell them.

For $616 million, the company installed scrubbers to reduce carbon dioxide and replaced the single 1,100-foot-high stack with two 830-foot stacks.