Bitcoin mining not profitable
I just answered a different thread and gave a picture of what I make in a week.
This is profitable for me for the following reasons:
1)bought the equipment before the popularity sky rocketed(must get GPUs at or under $275 each. They are out there but it takes time to find them now)
2)This is big-free electricity-plugged into power at my work, enables me to deduct costs due to the fact that its an expense and I own the business. You may want to start an LLC so you can deduct this expense. Make mining a business. Sorry just read that you have free power so this can be a money maker for you.
3)Got in early
Dont let the above deter you. This is an extremely fun hobby and can be very rewarding. I would get in now. Oh and you should not mine BTCs you should mine alt coins to sell for BTCs. That is the only way to make BTCs through GPU mining that is still profitable.
Get into a pool that mines multiple coins. The pool mines whatever coin will get the most BTC when sold at that instant in time. Then when you have at least 1 coin send it to an exchange to sell. This is all done automatically once you setup your parameters and payout addresses in the pool. Its all pretty amazing stuff. Hope this helps you.