If you’ve deployed a new feature as part of your solution and for whatever reason it doesn’t show in the UI (Web Features or Site Collection features). You can run the following powershell commands:

This will show you any features that are available in the SharePoint Root but have not been installed. Then to install the missing features:

More information: http://technet.microsoft.com/en-us/library/ff607825(v=office.14).aspx