AEP, of Columbus, Ohio, is one of the nation's top coal burners and stands to be among the companies hardest hit by tougher EPA rules.

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Similarly, Ohio-based American Electric Power (nyse: AEP - news - people ) last month announced plans to place carbon capturing technologies on two existing coal plants by 2011.

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In the U.S. a dozen utilities, including Ohio's American Electric Power (nyse: AEP - news - people ) and New York's Consolidated Edison (nyse: ED - news - people ), are running small tests of the technology at anywhere from 3 to 250 homes each.

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