The chassis will suck about 50W without even a single drive in it. Drives are SAS and will draw about 7-9W each, adds up quickly. As for spin-down, these bad-boys are designed to hang off some pretty big enterprise servers, spin-down is not normal needed and if you have noticed, you may also have amber lights on the drives which says ISSUE but as we don't have full control of the chassis to program and communicate with them, bit of the wild west.