How do powers work?
The left-hand-side menu powers function similarly to the “Generals’ Powers” or “Ring Powers” in previous EA RTS games, but instead of being tied to your “experience” in the match, they are tied to specific buildings. If a building providing a power is destroyed or powered-down, that power becomes unavailable until you reconstruct or re-power the building. Also, all powers in C&C3 cost money to use. If you do not have the required amount on hand, in full, then you cannot use the power.