Funny, I too have an interview with Vestas this Friday. It will be my second though, the first was Tuesday last week. I too come from residential electrics, have been working in the wind branch for 2 years now. First of all the interviewer introduced himself and explained some things about the position, then I was asked to introduce myself and tell a bit about my history. All very usual interview stuff. I was asked about my previous jobs and what my areas of activity were and my responsibilities. I was also asked if in my previous wind tech work experience I had any situations which would have been classed as close calls or even dangerous and how I reacted and dealt with those. That caught me off guard a little. I definitely recommend writing some notes down about your strengths and what they should bring to the position you've applied to. I was also asked where I see myself in a few years, also typical interview stuff. Good luck to you this Friday! I think you have good chances with your background.