The most detrimental graffiti vandalism occurs during dark hours. Graffiti vandals find night time beneficial, as it helps protect their identity from witnesses and the police. Properties with poor lighting help the vandal go unnoticed as they do their damage if nobody notices the police will not get a call, so the vandalism will continue throughout the area.
If you've had a reoccurring graffiti vandalism problem, you may want to update your outdoor lighting to deter future vandals. A great choice would be motion-activated floodlights. These types will allow you to set the day/night usage, sensitivity to activate, as well as the light's duration. The dark/photocell activated lighting systems can be very inefficient due to the fact they continuously run for 8 to 12 hours every day.
My Graffiti Removal Guy recommends the motion-activated type. These are available in many different styles; the model you want to use is L.E.D. lights. L.E.D. Motion-Sensing Floodlights are incomparable in savings on energy. L.E.D.'s also last 10+ years while you'll be lucky to get two years out of a typical floodlight. Also, L.E.D. bulbs are tiny, making it harder for a graffiti vandal to bust with a rock. With any light system you use, make sure to put them in hard to reach places to avoid them being disabled by vandals.