There aren't too many options for emulators for Super Cassette Vision, but a couple of good solutions are available. The one I recommend is a program called MESS (Multi Emulator Super System). In fact, hundreds of other older systems can run on this single program, so this will come in handy if you want to run other retro machines.
Note:
Go to the second table for MESS.
(The first table is for MAME, which is different)
There is a catch, though - you have to supply your own copies of the SCV BIOS files (there are two) and ROM files for cartridges.
(Well if you're persistent enough on the web.. you might just get lucky :))
Installation and running has some running curve because you have to be pretty specific about paths and also need to run the program from the command line. I suggest reading the following pages closely first:
Another very good SCV emulator is eSCV. This one is a little complex, too, but people say it's remarkably good. The developers have spent several years tweaking this emulator, so no wonder everyone seems truly impressed!