Volumio on a RasPi 3B+ - is there a sleepmode?

Hi,
I have volumio on a RasPi 3B+ running. Very nice system.
I am asking myself if the system is going in some kind of sleepstate if nothing is happening? Or shoul I power down the system to save energy?
Any advice?

If this is the wrong place, please move.
Thanks.

F.