The Psi Lab facility, upon completion, allows you to send a Rookie for training, and after a few days he / she will come back as a soldier of a new class, the Psi Operative. However, the function of the facility does not end here, as the Psi Operative cannot gain experience points like other soldiers do (by killing enemies). To advance him / her on higher levels and unlock new abilities, you will need to place the Psi Operative back into the Psi Lab to perform further training.
It's one of those facilities that should be built as early in the game as possible, as training a Psi Operative takes dozens upon dozens of days, especially if you want to unlock all the abilities available to them. And you should do so, as the Psi Operative is probably the best soldier class in the game.
Upgrades and staff influence
20x Elerium Crystal
Construction takes 11 days.
Monthly upkeep cost - 55x Supplies.
- The possibility to train and further develop a soldier of the Psi Operative class.
Second Cell: allows you to train two soldiers simultaneously.
Cost: 225x Supplies, 15x Elerium Crystal 5 Power. Monthly upkeep cost - 55x Supplies.
Staff: up to two soldiers.