I have seen used bathroom shelves or leftover louvered-window glass hung in a window to fill it with shelves. Much less hardware and no need for the glass to be cut to fit exactly. You'd put eye bolts top and bottom, and use wires strung through tubes at their crossings to make shelf-holders. Shelves sit on them with silicone plugs or other traction material to help hold them from slipping; the items sitting on the shelves hold it all in place.

~S~