Keeping your computer in standby or sleep mode is a great way to
save energy and lower your electric bill. Unfortunately, Windows
sometimes interprets network activity or other signals from
peripherals as reasons to keep your system wide awake. To nudge
Windows toward the land of nod, try CO2 Saver. The Custom Power
Saving dialog of this freeware tool has a checkbox that does just
that. It also sits on your desktop and shows you just how much CO2
you (and others) have saved this way. CO2 Saver also includes a
configurable Web search bar, which I avoid since it routes search
data through Snap's servers for their own uses.
Note: This link takes you to the vendor's site, where you can install the latest version of the software directly onto your PC.