Hello is there a possibility to force OWA light in Exchange 2013 promise.

Not the Option field on logon page....I used some powershell code, but nothing helps:
Set-OwaMailboxPolicy -Identity Default -OWALightEnabled $True

In Office365 I saw, that there is in the Display Settings an Option to Switch between light and premium Version.

thank you verry much for a Idea

I'm not sure that you can force OWA light, but what you can is to enable option for OWA light on logon page.

Execute this : Get-OWAVirtualDirectory | Set-OWAVirtualDirectory LogonPageLightSelectionEnabled $true 

Try running this command:

Set-OWAVirtualDirectory -identity "servername\owa (Default Web Site)" -LogonPageLightSelectionEnabled $True

Then do an IIS Reset

http://technet.microsoft.com/en-us/library/bb123515(v=exchg.150).aspx