I am like PaulH and MichaelW.
I have a hub generator and Lumotec headlight, which are permanently attached to the bicycle. As for taillights, I have one Planet Bike or Vistalite (depending on bike) permanently attached, and I add more for longer rides.
In my main "basic" pannier, I have my food, extra clothes (raingear, sweater...), pump, tubes and tire patch kit, so all come in a single piece when I arrive at the office.