I applied online. The process took 4 months. I interviewed at Cleantech Group (London, England) in Sep 2017
Interview
The process was fairly straightforward. CV and cover letter, a phone chat with one of the research team, an excel analysis based data task followed by a casual interview with a few members of the team. The only issue was the length of the whole process. Having applied in July I ended up starting work for them in November. However, this was necessary for the company. If you are genuinely passionate about the field your interests will be clearly justified through each stage.