I applied for the graduate engineering scheme based in the renewables department. There was an application form with standard questions (why do you want to work for Scottish Power etc.), then some online tests, then a video interview. This was one of the better video interviews I did as you could review and re-record your answers if you made a mistake. Then I was invited for an assessment centre in Glasgow which had three tasks - a presentation to two staff members where we were given a booklet of information beforehand, then a interview with two other staff members, then a group discussion task. I wasn't offered a place, but they gave me really detailed feedback going through all the steps in the assessment centre over the phone.