yes, check the red link in my sig to see how cfls can work...
you want a mixed spectrum of light, even for flowering. During the first 2-3 weeks of 12/12, your plant will explode with growth and still needs some 65k light. After that I tend to go heavy on the 27k but still a few 65ks here and there... If you manage your canopy correctly and place your lights strategically, CFLs will do a great job. =)