I have arranged over time with tax-exempt charities to take my works that I display but do not sell.
I ask that they display them in a public access area, often with a small plaque crediting me. After a reasonable time, they can do as they wish with the images. Generally they become more or less permanent.
I've learned, also over time, that just because they are free doesn't mean someone wants to hang them.
But I far prefer that the ones that don't sell hang on a public wall rather than in my garage. Mine usually end up in hospitals or patient care facilities... so I know someone is enjoying them