GE and others have the ability to build and or repair turbines in the United states, in many different regions, in fact.....
Not on the scale needed after a large or staggered EMP over Central US. Most of the power plants nationwide would be fried. (And we are talking about turbines which generate electrical power - not turbines that run jet engines to be clear here?)
I was not able to find out exactly how long it takes to make a single turbine generator, but I did learn that most of the market is currently dominated by China ...
In any event, we would need hundreds if not thousands of these devices each taking month to a year to produce - then there is the shipping, the installation, and the testing before they would come on line.
Start stocking up on bituminous coal now, it will be a very long winter and, coupled with the Super Grand Solar Minimum, very cold for the next 350 years ...