Thank you for the update. Very informative.
You factor broken gear, but what about decommissioned hardware ?
When difficulty will go up, old hardware (1-100Gh/s) will eventualy be sent to the trash.
It may amount to 1-5 Phs.
I doubt they'll hash forever, even if some people have access to free power.
Eric
I am remember someone calculatiing that at current BC pricetag even the least energy efficient asics out there are still profitable until multiple b difficulty. If this is true people will not turn them off. Would be glad in case someone could dig this out. Will also keep my eyes open on that point