Storing unused books, including textbooks, is a waste of space. Books do not store well in dark, damp spaces, like in unfinished basements. Many local libraries accept book donations, which they, in turn, sell to benefit the library. Of course, recycle any books that can't be salvaged.
25 Things in Your Basement That a Professional Organizer Would Throw Out, Source:https://www.rd.com/list/things-in-your-basement-that-a-professional-organizer-would-throw-out/