What will happen to our div's if power costs are higher than the amount of bitcoins? I don't want to pay on top of it to get overpriced div's at the end...

If the cost of power rises higher than the bonus amount, you need to cut Lab_Rat a check every week to help pay for power.
Lol. Don't remember that part in the contract -- either version.
I 'd guess operating expense runs somewhere around $3k a week. So, I'd guess that somewhere around $200/btc, there is no bonus, and lower ends up being Bad news. In the endgame, Zach would forego his comp, to see if btc snaps back. If it doesnt, then things start going dark, since electric bill couldnt be met. Theres potential that things get ugly quickly. But, btc is incredibly volatile. Its insane to do forecasts, since normal range corrections in either direction is massive.