What is com.apple.preferences.users.remoteservice and why is it using significant energy in my new mac?
Some System Preference panes in Mavericks are built in a way to separate certain tasks into XPC processes. 


  The idea is to break up a complex application into individual processes, each of which requires only the few entitlements necessary to perform a specific subset of the application's total capabilities.


com.apple.preferences.users.remoteservice is one of these XPC processes. If you locate the process in Activity Monitor you should be able to tell which preference pane launched the process by the icon. In the screenshot below the process has the Users &amp; Groups icon indicating that it belongs to the Users &amp; Groups preference pane.

I'd check first to figure out which set of preferences it belongs to and make a judgement call on whether it makes sense that it is still running, but if one of these processes is using a significant amount of energy (and is still running once System Preferences is closed) I'd assume something has gone wrong and kill it. 

Something you could do to attempt to understand what this process is doing is to open the Console application on your Mac and enter "remoteservice" in the filter box in the top-right corner. I'm assuming if the process is using a significant amount of energy then it is struggling to do something and will have written quite a few errors to the system log about what it is trying to do.