A flip-flop does one thing and one thing only...it runs the ballasts 24/7 but every 12hrs it switches the lamps it is powering in two separate rooms. If you run 8K, you pay for 8K. It doesn't matter if you run all 8K at once for 12hrs a day or you run 4K for 12hrs and the other 4K the other 12....you pay for 8K.

There is something called a Power Factor corrector on the market. For the small timers, it is pretty much a snake-oil pitch. You gotta be powering up huge before this thing MIGHT even reduce your bill, and even then...BS most often.