I applied through college or university. I interviewed at RES (College Station, TX) in Sep 2017
Interview
The interview process is professional and it is in depth relating to what you are interning for. The questions they asked me was completely topic related. This is one of the most professional company I have seen.
Online list of around 10-20 questions with free text answer boxes about understanding of renewable energy systems, knowledge of the company and my relevant experience. Unfortunately I did not get past this phase.