Well I think your first step should be to find out if it's true that you are having elec probs from your light...
Check out what circuit on the breaker box your light is plugged into, and then find out what OTHER things run off that circuit. Try to set up your grow to be the only draw on a circuit... or share one with nothing but a couple lights that then can be changed to CFLs. A 20-amp breaker will power your grow just fine without causing electrical issues.
Next, ask your mom to consider letting you pay a share of the electric bill. Find an OLD bill from before you started growing, and see what the difference is. I pay the electric for my entire building, which consists of 2 apartment units, one of which was occupied by a dude who left his HUGE tv on 24 hours a day, along with every light in the house, plus my ~2500 watt grow, and I have never had a bill over $150.
If your mom still objects, you should ask her very nicely if it is something else that is bothering her... not the elecricity at all, but something else?
For flouros, it's going to be rough imitating HPS light. Those T5 new wave fixtures are pretty awesome, and some people can get great results using just CFLs, but honestly try to get your mom to let you finish up this one grow befoer you switch lights, because by then it will be almost spring, and you can focus on getting some plants going for the outdoor season.

I hope this helps!!!! Happy growing!!! I'm glad your mom is chill with it!