I did the math on HDD power usage recently, turns out you can save quite a bit of power and money by going with less higher capacity drives vs more lower capacity drives (with the extreme case of 12x used 1TB 3.5" costing twice as much as 1x refurb 12TB in a year, despite nearly the same initial $/TB). 37W in a year tallies up to 324kWh in a year (of 24/7 usage). Assuming 0.283 €/kWh this amounts to 91.72€.
TFW it’s cheaper to replace a CPU than a fan 
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