Solar panels can be recycled in some places but yes solar panels are considered hazardous waste in some places.
The solar panels are made with things that are hazardous such as sulfuric acid and phosphine gas which makes them difficult for some places to recycle properly.
Some people will take them off your hands though if you set them out for scrap and scrap metal recycle people will come by and pick them up with other scrap and then recycle them.
Solar Panels contain some aluminum and other scrap metals that can be valuable to some scrap metal people so they will be usually willing to take the old solar panels from you for free.