Look at this, we've infiltrated a power relay station. This could be helpful if we have some extra PWR to sell. The station only manages large exchanges though.
—Central

Power Relay Station is a side mission that has a chance to appear in a mission. Its purpose is to sell PWR for credits. It consists of two Relay Switches that are placed in random locations in facility, and an unique room that contains a Relay Transformer.

Power Relay Station side mission is only available with Contingency Plan.

You'll need to find a second switch. Activate them at the same time and we will have access to the power transformer, wherever that is.
—Central

Relay Switches are Mainframe Devices that are exclusive to the side mission. There will always be two of them, placed in random locations. They must first be captured by Incognita and then activated at the same time (in the same turn) to unlock the Relay Transformer. They are mostly located far away from each other, so two agents are required to activate them, however, sometimes they are close to each other and can be activated by one agent.

Excellent, the relay station should be open now. If we patch into the relay transformer, we'll be given a chance to sell off a large amount of PWR. I leave it to you Operator, if you think we can spare it.
—Central

Relay Transformer is a unique room exclusive to the side mission. The door to the room is initially locked and cannot be opened. Once the Relay Switches have been activated, the door will open and will behave like a normal door, being able to be opened and closed. Inside the room there will be a Relay Transformer Mainframe Device that can be used to sell PWR. To use it, Incognita must first capture it, and then an agent must interact with it. You need at least 15 PWR to use it. Once used, it will deduct 15 PWR and give the agency 500 credits. After that, it is unusable for the remainder of the mission.