Steering can be very heavy to drive if not working, but should be ok to drive to dealer.
Citroen/Peugeot can suffer from faulty ignition switches which can cause the problem. Can also come on, if the alternator is not charging correctly. Check for blown fuses, try disconnecting battery for 5 minutes may reset ECU.
The electric power steering motor is part of the steering column (see picture) and can be fitted in a small place (small cars) and only uses power when turning steering so is more economical than conventional hydraulic power steering.