At Global Power Plant Database is an overview of all known types of powerplants.
You can also download the database in .CSV format and have the coordinates included to make a .KMZ and from there to include in your scenario.
Some countries are easy and have only a few coal or gas powerplants. In the UK or Germany you have to destroy all the solar power plants.. [:D]
Take a look, it is a nice one on-the-side to have on your target list [:'(].
