I use a X10Pro Wall Switch Appliance Module to control a PRS511, timers can be set to it so the PRS511 is off during the daylight hours, saving current. Works for me.
I use
several PR511 and non-X10 motion sensors floodlights around my home. All are set for nighttime motion only. It does save a bunch on electric use. Also... I've read that lights coming on as an intruder approaches is a greater deterrent than lights on..
all night long. I use enough lights (on motion) that I could play sports in the yard at night.
Of course... I also use cameras (also triggered by the PR511) and
a computer voice... camera warning announcement seen
here in my YouTube Video.
I also use hard-wired LED Lawn Lamps. They only use 8 watts of electric... yet remove shadows and give the properity a warm lived in look. I also have LED lights (and one CFL)
inside the house, controlled by the PR511 dusk/dawn sensor... as well as timer macros. They create an "at home" look and provide enough light to [again] remove shadows and provide walking around light [and are on only during waking hours]... at less than 20 watts.