[jpcfl]

That wasn't my point. My point was that they could stay in business.

My original point was that it was in the ballpark of $2M. Could be more, could be less, all depending on a number of variables--I believe one of those variable just doubled.

I'm not sure what the cost is now, but back in 2012-ish when I briefly looked into mining, it cost about $1 in energy to mine $1 worth of BTC. I used your logic and decided it didn't make sense to invest in mining, so I didn't. I wish I had, or at least purchased some BTC, but I was a broke college student just looking to capitalize on the hardware I already owned, and I didn't really know a thing about investing (other than investing in a 6 pack of beer to meet girls at parties--my ROI was not great, BTW, so I don't recommend this strategy).

[quesera]

I sympathize! I considered running a miner in 2012, with the positive side effect of heating my office. Decided I didn't want to listen to the fan noise for negligible returns.

> it cost about $1 in energy to mine $1 worth of BTC

This is the crux of it (we may be saying the same thing!). There is no 1:1 relationship between mining cost and reward on a single block. If there was, no one would do it, because they do not win every block. And all blocks you compete on cost the same, win or lose, but of course the blocks you don't win, pay zero.

There's a (very) roughly 1:1 relationship between a miner's overall cost and reward, averaged over many blocks. If reward increases (BTC price spikes), more competition comes online and your win frequency drops.

So if the question is "how much energy (cost) did it take to mine this specific $2MM block", the answer is closer to "The average block reward divided by the winning miner's win frequency", which is e.g. 5% for one of the bigger miners (I did not check this block or this miner). This was a high reward block, so the real miner cost might have been more like $50K. Less for energy alone.

But it's like the guy who buys a $10 lottery ticket every day. He needs to win a few hundred dollars per month to maintain the habit (gambling addiction notwithstanding!). Today he got lucky and won $700 on the $10 ticket.

[jpcfl]

> There is no 1:1 relationship between mining cost and reward on a single block

Ah, I see what you mean.

I think I've been mixing up my costs. When I wrote the original comment, I was thinking about the total energy cost for mining this block, i.e., the energy cost of all the nodes that worked on it. But the truth is, I have no idea about the economics of BTC mining. I was just being facetious :)