I read that many spreads are non hydrogenated, so then how are they made solid?
Olive oil contains a certain percentage of saturated fats, which are probably separated out and used. Alternatively, there is a process called interestification that is sometimes used to make more solid forms of non-solid fats without hydrogenation.
I can't say for sure, but it's possible that it's simply achieved through temperature -- olive oil will solidify in your refrigerator.
(I make basil infused olive oil, which I then keep in the fridge. You have to keep it in a jar so you can extract it, because it won't pour at fridge temps)