Have you seen this thread: Seeking not-too-competitive science program for rising junior? Some of the recommendations there might be of interest for your son as well.
With respect to business and renewable/sustainable energy, I’m there are lots of options out there, and I would imagine that at many colleges he would specialize in one and minor in the other, or perhaps do a double major, etc.
One major that might be of interest is Environmental/Natural Resource Economics. Econ is not business, but it might meld some of his interests. Juniata, Michigan State, U. of New Hampshire, and U. of Rhode Island all offer this major and seem to have some related majors that means they’d probably offer some pretty good strength.
But what area(s) of the country is your son interested in (or interested in avoiding)? Size of school(s)? How does he feel about the importance of college sports or Greek life? What’s his academic background? What’s the budget?