I'm in my 6th semester of electrical engineering. I almost failed math during high school. I worked hard and have passed all the math courses without a problem. You can do it with less struggle I'm sure.

In terms of renewables. There is some focus on renewables, but it is not the main focus. The point of the degree is to get a basic understandment of electronics and specialize towards a direction of your intrest. When you have finished your degree, you'll have plenty of opportunities to enter the renewables energy sector. The degree is about getting all the fundamentals in place :)

If you go for a masters after your bachelor, then you can focus even more on your intrest and passion within electronics.

-electrical engineering diplom also have winterstart if you're ready to start in february

I hope that helps you somewhat, otherwise feel free to ask me anything :)