That is like, only 25 cents an hour.  Really not worth your time.  You can do much better.

Stay away from gambling, it is for fun only.  It is not a good way to earn money.  Maybe you get lucky maybe not, but its pretty risky.

If you have free electricity, then your best bet is mining imo.  But this takes start up capital.  There are many used units of various manufacturers around, I can't say what is the best price.  You have to find out for yourself.  But you can find good deals sometimes.  Look on these forums, on ebay, etc.  Check out the mining sub forums and learn a lot before you pull the trigger on mining.  I think it is not that easy, and you really need some start up money to get going.  However having free electricity is a huge advantage.  If I had free electricity, I would run a mining farm full time.  In fact I might even get a loan and sell my car to do so

Good luck!