How long do you have to complete the project?

I think something interesting at least at the high school level would be to re-create an analysis from an already published paper using their data using your own pipeline (using something like snake-make and incorporating maybe a different aligner or peak caller or etc). Present a poster on the findings and talk a bit about your pipeline and just give a very brief talk about how powerful bioinformatics can be in science.

It's obviously not something novel or 'very difficult' but it's definitely something you won't usually see at a high school science fair, and learning how to use some of the already built tools is a decent challenge in itself and is great experience.

Google Science Fair 2016 is here