To be fair, 1TB drives is probably an extreme example, but…
Just did some quick and dirty, but accurate calculations.
Assumptions:
Domestic kWh rate used is $0.12 (probably fairly reasonable but I don’t reside in USA so not sure)
XCH price as it is now, $42 per XCH
XCH price and Electricity price stay the same over the 5 year illustration
Power consumed per drive based on largly idle useage, spec sheets and from my own measurements
Disk prices from diskprices.com, assuming purchased new, cost of drive covered in Year 1
Plots per disk based on calculations (a few might be off slightly as I don’t personally own all sizes)
Income of XCH taken from chiacalculator.com
So there we have it.
As can be seen, 1TB & 2TB drives make a loss in the 5 years.
18TB drives make the most profit.
20TB drives not cost effective yet due to price premium, but still more profitable than anything less than 12TB.
6TB drives represent decent mid-range value, being slightly more profitable than 8TB drives and earning 42% of the profit of an 18TB drive for only 33% of the capacity.
Profit in descending order are:
You can read any and many things into the above but these are sound calculations as I see them.
Bottom line If you have to pay the above prices for disks and the above costs for electricty, 18TB is the best bet. But not everyone does, YMMV.