I haven't really found any good solar books at our library, although I've looked. Some of the books they do have are pretty woefully out of date and almost all focus on residential solar systems - way more than anyone would consider for their RV.
I think one of the problems with experts writing a book is that the solar world evolves and changes fairly rapidly with regard to solar prices, efficiency, and technology, such as batteries like lithium-ion becoming more common. So while some of the basics (doing an energy audit, etc) stay the same, most people aren't interested in buying a book that doesn't have all the latest information in it, and therefore, publishers probably aren't that willing to take a chance on printing up copies that will just end up in the discount bins for lack of market.
