To start, you don't have free electricity, someone is paying for it, in this case, its the tax payers, and I don't necessarily think its a great idea to waste taxpayer money on electricity bills to make you money. Now you may be thinking, this is a small operation, but with an S1 and 2 S3's your talking $60 to $70+ a month, depending on electricity prices. Plus cooling costs on top of that, I would imagine over $100 a month is going into running these units, and that is something I would imagine most taxpayers are not OK with.
So please consider the fact that you are now using quite a bit of taxpayer money to gain bitcoin. Its also important to note that a utility bill increasing like that all of a sudden would not go unnoticed, along with unusual traffic on your network. There have been numerous reports about people getting fired for running miners at work, and it is my personal belief that it is not smart to mix mining and work, especially by not getting prior approval and explaining what your doing.
Don't get me wrong, I am all for teaching kids and really respect teachers, but I am not sure what running bitcoin miners in the classroom is teaching? By the sounds of your post, you teach economics or some branch of that topic, so the idea of decentralized virtual currency is definitely important, but the actual mining is not. You could teach the same lesson by buying a small amount of bitcoin and sending it to the kids on a wallet app on their cell phones.
Again, please just consider the above points. Its not free electricity, someone is paying for it. You can also get in a lot of trouble as I would assume the board or PTA type group looking into an increase in the electricity bill wouldn't view the running of bitcoin miners in the classroom as a good form of teaching when its making you money.
Sorry to have upset you, let me try to address a few of these issues.
We are a very technological school district. Upon entering 6th grade, every student is issued an iPad (they keep it 24/7, it's not just a class set) and most (not all) work is done digitally. My school alone has over 3 thousand students (graduating classes of over 750). We have "charging stations" in every classroom as well as the library, cafeteria, and band hall. There are teachers that leave their projectors on all day (crazy, I know!) just to have a pretty background on the wall. Don’t forget about the electricity used to power the “Jumbo Tron” and Lights at our football stadium, or the electricity used to maintain the Natatorium (huge swimming pool) for the swim/dive team. I, as a residential customer, only pay $0.0670 per kilowatt hour... now imagine how cheap the electricity is bought by the school district. We have put in to place ZERO measures to save electricity. Our Air Conditioning/Heating systems never turn off, not even on weekends or during holidays. In fact, I've been working in my classroom during Christmas break only to find lights all around the school have been left on, the A/C is blowing (it didn't get cold until the beginning of this week and nobody has even adjusted it), and every single computer in the school is still running. Plus the copy machine in the Work Room has been stuck on “Paper Jam” since December 18th (the last day of school this semester).
So in a school with over 230 teachers that have at least 2 computers in each room (I only have 2, our graphics design/photography/computer science teachers have about 30 in each of their rooms), ~3000 ipads being charged daily (they are charged more as they age), plus the electricity being used for the compressors, welders, and other heavy shop equipment, my ONE 350 watt Antminer S1 is a drop in the bucket for a school that obviously gives very little thought to its usage. Nor would it be “detected” (laughable). Do you think the school district’s accountant, in his office across town, is going to say, “ZOMG! The High School’s electricity usage went up 0.00003%! I’m not paying this bill until I find out what miniscule little thing added to the hundreds of Megawatts of electricity we already waste!”? No, of course not.
Hell, the Computer Science Club *should* hold a fundraiser from parents/boosters to buy S5s and run them continuously at school to earn BTC for the club!
But yes, you are right… tax payers fund our school district’s electricity bill (and my salary) and your comment has given me a lot to think about. They do not, however, pay for the hundreds of dollars I spend on supplies that are required for me to do my job. Imagine being a computer programmer and having to buy your own computer, or a construction worker that has to pay for the building materials. Dry erase markers (expensive!!), staplers and staples, flash/portable hard drives for my digital content (not allowed to store it on district drives/local hard drives – against policy), hole punches, construction paper, pens, pencils, markers, computer speakers (not provided by district), my mini-fridge/microwave (not provided in the teacher’s lounge – I guess I could do without if I didn’t want to eat lunch or enjoy cold water), and a bazillion other things that I’m probably forgetting. Why not use the BTC that is made (after I use it to buy pizza for the kiddos, which I already promised) to buy supplies from Amazon.com (accepts Bitcoin, yay!) that *should* be in our non-existent office supply budget? Sorry, I don’t feel bad for that.
Please also understand, this isn’t something I am hiding. I’ve finished lesson plans for all of January (whew!) and have written them in as my “materials.” This will be approved (I mentioned it, in passing, to my AP and he thought it sounded cool) – it’s not something I’m hiding or “trying to get away with”, hence my statement about putting it in the Band Hall or Auto Shop if it’s too loud/hot. The bandwidth required to mine is tiny. Only megabytes a day, which is way less than when students stream Netflix on their iPads during lunch and before/after school, or teachers that stream Youtube videos.
Sorry my post bothered you, DebitMe… but there’s worse “wasteful spending” of tax dollars happening. It could be worse, I suppose… I could be using tax dollars to earn BTC and losing it to online gambling sites (because that’s not worse)