powershell problem when running on a remote server - access is denied as a follow up from this question below:

Run a PowerShell script on a different server - from inside a SQL Server job

there you can see that for me tu run a powershell script from inside a sql server job, I need to create a proxy.

Both the powershell script and the proxy script are on that link.

what the powershell script does is to delete old backup files on a remote server.

the question that I still have is:

for the whole thing to work on windows server 2012, I could find not other way than granting Administrator on the remote box to the Proxy account.
as you can see on the picture below.



another alternative was to 
create a powershell script that do both, backups and deletes, and create a sql server job with the following code:



Is this a powershell limitation when running on a remote server?
Are there other ways to work around it, without having to grant admin to the proxy account?

PowerShell Basics: Managing Remote Servers &amp; Sessions
The account being local Administrator is a requirement for using the Enter-PSSession:


  To connect to a remote computer, you must be a member of the Administrators group on the remote computer.


As far as workarounds, I did find this answer on SU. I would read the article in detail that the answer points to fully understand, but this is the main command to adjust permissions:


  If you decide you want to allow others, what you do is run the
  command: 


Set-PSSessionConfiguration -Name Microsoft.PowerShell -showSecurityDescriptorUI 



  Notice that this action could have a serious impact on your system so
  we ask you to confirm that you really want to do this.