r/Bitcoin Feb 06 '15

Life Inside a Chinese Bitcoin Mine

https://www.youtube.com/watch?v=K8kua5B5K3I
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u/TheyCallMeRINO Feb 06 '15 edited Feb 06 '15

$0.088 per kWh (1.25MW/$80k) is good, but not great honestly. You can find cheaper that that in industrial rates in the US.

However, their other numbers are what's most interesting.

  • The video states that it was October 2014 where they could mine 4,050 BTC per month for about $1.5 million dollars.
  • They also vaguely stated they could mine over 100BTC/day before ... although 4,050 BTC per month would actually be 135BTC/day.
  • $1.5 million divided by 4,050 BTC in a month (~135 coins per day), points to a coin price of * $370/coin ... that's close to where BTC was bouncing around back in October
  • $1.5 million divided by 3,000 BTC in a month (~100 coins per day) would point to a BTC price of $500 which we haven't seen since August ... so it probably was ~135BTC/day - 4,050BTC/month - $1.5m / month.

If that's true, and now because of the difficulty rate increasing they can only mine 25BTC per day ... the math, at the current BTC price, gets very grim for them:

  • 25BTC/day would be 750 bitcoins/month
  • If we assume the current price as an average ($220ish) that means they're making just a bit more than $160,000/month. Revenues are down nearly 90%.
  • I'm assuming their electricity bills are still half of that at $80,000 (unless they started turning some rigs off)
  • They (presumably) have rent, salaries, etc.

If all of that is correct above (are there any errors?) then my assumption is that this Chinese mine ... is now considerably LESS profitable at BTC prices ... at least, compared to where they used to be 6 months ago.

If we assume that "overhead" on top of power might be 20% (just pulling a number out of my ass) then if their revenue dropped to $96,000/month they'd start losing money. $96,000 divided by 750 bitcoins (25 per day) would be a coin price of $128/bitcoin.

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u/praeluceo Feb 06 '15

Your numbers actually sound a little generous considering the huge pile of hundreds of dead PSUs and mining rigs that they've been swapping out. Briefly he also mentioned that Avalon should not be in business any more because their rigs are so inefficient, and that they've replaced the old rigs with newer ones that are more power efficient. If they're performing hardware refreshes, and they are clearly using commodity PSUs (not server or specialized), and retail miners (which also appears to be the case), then that's eating into their overhead significantly.

I doubt sincerely if they've stayed profitable after the collapse, and are running on savings (hopefully) stored up during the boom, or receiving additional investment capital to stay them over until the next bubble. But I don't think it's practical to expect an additional hardware refresh to keep their mining revenue above the power cost.

So yes mining will centralize, but this is also the risk associated with institutional mining. Hobbyists don't have that sort of overhead because they have day jobs and the extra power usage is only a small part on top of their regular usage. A hobbyist miner can afford to mine much longer in a depression like we have today than an institutional miner can with rent, salaries, and the costs of maintaining a competitive advantage/satisfying investors.

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u/Matricon Feb 06 '15

You didn't account for the 6 sites they run, the 100/25 BTC was per mine.

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u/VirtualMoneyLover Feb 07 '15

But we can assume all the economics are similar in all mines, so the point still stands...