I think that SOLID on IPFS would be problematic. RDF can use HTTP but technically doesn’t rely on it. It does rely on URI’s, how you dereference them is another matter. (you can use mailto:, tel:, etc just find in RDF). Linked data, similarly, doesn’t require HTTP even thought that’s what everyone uses.
I think the problem is going to come with IPFS being content addressable and RDF not having a canonical representation. N-triples/n-quads will be the closest you’ll get but you’d still have a problem with anonymous nodes, aka blank nodes. There are things you can do to work with them but you’ll get into all kinds of crazyness with skolomization, graph isomorphism, blah, blah, blah.
I think you’d end up making heavy use of ipns and negating much of what you want from IPFS. That being said, I’m very interested in how you could use IPFS and RDF.