Power plants are devices built to produce energy from wind. They have neither defense systems nor armor.
Tactical importance of power plants is completely marginal. Every military building used by both Toricon and Consortium has its own power sources, thus any action against the power plant does not mean any harm to any side of the conflict. These facilities are supposed to be used only in the civilian sector.
The Signus units have no orders to capture the power plants and their desctruction is strongly unadvised. “It takes just a few dimes to build a power plant but the thing you’ll use to destroy it takes a fortune. So if you’ll just shoot to them, you bet that the command will deduct all costs from your wage.” – unknown soldier’s comment in the rookie’s manual.
(Note: There’s nothing to find on the power plant officialy in the game, neither a description, or an icon. You can just come across it while playing. Despite its uselessness it reamins one of the buildings. So I decided to make its description myself.)