As you & @GramThanos discussed in comments, the original
hd-idle may be capable of improving your drive's energy efficiency. However, it was last updated in April, 2014, which suggests it has been orphaned by its author. If you want an open-source solution that is more current, the
hd-idle distro on GitHub is claimed by its author/maintainer to offer "Extra features", and from its "star count", it appears to be well-received by its users.
I've not tried
hd-idle myself, so I can't say if the
armhf.deb binary will work with RPi - or whether building from source is necessary. However, like most GitHub repos, you can get support through the
Another option is to grab one of Seagate's "SeaTools" from their website - at least some of them are available in a "Linux" version.
But perhaps the first thing to try is the
hdparm tool as discussed in this U&L SE Q&A.
hdparm is in the RPi repository, and may be installed as follows:
# make sure it's available:
$ apt-cache search hdparm
blktool - tune low-level block device parameters
hdparm - tune hard disk parameters for high performance
# install in the usual way using apt:
sudo apt-get update
sudo apt-get full-upgrade
sudo apt-get install hdparm
It seems there are several
hd-idle-inspired tools available that can reduce energy consumption. If you follow up on this, please consider posting your own answer, and share your results; I, for one, am always interested in energy-saving ideas for my off-grid projects.