Can anyone give me some guidance on some online research I have to do?

I have my first assignment for my internship. I’m supposed to gather information on the leading research on top sustainability technologies. Have to get who’s doing the research and where, what organization/university/laboratory etc. and contact info of people involved. I’m having trouble figuring out which institutions are the LEADING researchers of these different technologies. For example, electric public transportation or nuclear power, I’ve been trying to figure out who’s actually leading the charge in those areas. Anyone have any advice?