The results get created and stored in the cloud. However, feature layers have an option to export the data, so you could download it from the cloud to get it locally.
I'm not sure you understood my original question:
Basically I want to know how to get geoprocessing results from ArcGIS.com to go to my internal ArcGIS Server instead of to the cloud. I asked if I need Portal to be internal to do this (do you know that you can actually buy an internal Portal that is installed on your local/internal servers instead of using the default cloud Portal? Obviously there is another cost associated with this, so I would like to NOT go that way if I can help it)...or if there is some other setting in ArcGIS.com that I can set to send the geoprocessing results to my internal ArcGIS Server instances. Do you know the answer to that?
Thanks Jake, that is good to know. My original question still stands, though: Is there a setting in ArcGIS.com (cloud service or SAAS) that can be set to send the geoprocessing results of ArcGIS.com to a local (internal to us) ArcGIS Server instance?