The the_power_plant.zip file you have requested: Maps / 4 Player Maps / The Power Plant - 8.3mb is not available. Perhaps try browsing all files for the game Company of Heroes and upload any files you want to share or are missing. This is the only information we could locate:
Here is another map from Eirwin Rommal. It is not too big in size but it is a hard fighting map. With 4 people, look at 1.5 to 2 hours of fight.