An efficient plant is generally less polluting. You'll also have incentives to retire your older, dirtier plants because they are less efficient. And the newer power-generation technologies are much cleaner. Replacing plants will result in emissions going down. Even though more electricity will be produced in a deregulated system because prices will be lower, I think that after the next five years we'll see a much cleaner industry.
Deregulation is potentially good.
But we're making a transition between a regulated monopoly and a mixture of regulated and competitive interlocking marketplaces. We don't have a history of doing it. There are two ways to proceed. One is to just blunder in, make massive mistakes and then try to patch them up later. Another is to worry about all of these things first, then try to do a good job right from the beginning.