You mentioned biology related research. Have you thought about research on plants? These are often easier to do on your own. Plant biology involves experimentation on plants at various stages of development. Another option is a field based project (ecology), where you could survey or study plants/trees/etc without any intervention. This is something you could do without a lab.
The tough part will be coming up with a scientific question that needs answering. Take a look at past Regeneron ISEF projects that made it to the finalist stage. You can get some inspiration from that.