you can get a 6500K 2 foot 54 watt T5 high output with ballast for under 30.00 online. that with a couple of 100 watt equivlant (26 watts each). thats a total of 108 watts, just about the same as a 100 watt regular light bulb and will be more than anoughf for three plants.
i vegged 12 plamts under 2 four foot t5's and 4 26 watt (100 watt equiv) and the grew fast, thick and strong.
keep in mind, cfls and t5's only put out 12 inches of usable light spectrum. so when they get over 12 inches keep the t5 just inches above them and lower the cfls beneath the canopy so you are getting 100% light penatration. you veg them 24x7 or to save energy keep your lights on a timer, 18 on 6 off. all light spectrums for veg state should be 6500K
when you are ready to flower you can switch to 2700K CFL's and a 2700K T5 bulb for $10.00 but you would be wayyyyy better off with a250 watt HPS. the light cycle changes then to 12 on 12 off so 250 watts for 12 hrs isnt much more than 108 watts over 18 hrs.
i know you wanna save electricity, but cfl buds are much smaller and fluffy while HPS buds are dense and much bigger. for the slight difference in your power bill you will get a much larger yield.