dToday's cleaner and more efficient combined-cycle gas turbines have relegated many older generators to emergency backup status in the dispatching pecking order. It is simply too costly in terms of fuel; O&M costs, and pollution mitigation to run older turbines with lower heat rates. Though it may not be possible to teach an old dog new tricks, fortunately, that isn't the case for generators. So rather than discarding old machines, some utilities are using them to provide synchronous condensing. Here's how four of them do it.