I need to do that as well. My sas drives idle at 7.7 watts and under load run at 11 watts a pop.

I have been turning mine off more frequently now that my electric rates have jumped 30% in the last two months. I'm currently looking to dump the 11 year old server hardware for both my nas and hypervisor server and consolidate everything into a modern lower power single system. Most likely using Truenas Scale.