I worked in a specific field of renewable energy until a few years ago and still dabble, but (disclaimer) can't pretend to be an expert as far as all types of renewable energy.
I would go with whichever type of engineering is most interesting and manageable to you because every major type of engineering (e.g., civil, chemical, mechanical, environmental) can lead to opportunities in renewable energy.
My background is in chemical engineering, which makes sense as far as anything that involves chemical reactions (e.g., where there are fluids flowing through equipment or underground). Mechanical engineers can get involved in building drilling and other equipment. Electrical engineers can work on converting solar or wind or geothermal (or whatever) energy into electricity or heating for buildings. Or on designing things like more efficient solar panels.
If there's a particular university you're interested in, it's likely that there will be an emphasis on certain types of engineering. For example, more of the professors will teach courses in a particular field of engineering and maybe there'll be more scholarships and internships and connections with industry in that field.
If I were you, I would approach the undergraduate counsellor at the institution(s) you want to attend and ask which types of renewable energy most graduate go into, because that's where the most job opportunities will be. There should also be statistics on average pay for each type of job. Good luck.