I came across this website a couple of months ago when I was looking around for a variety of project ideas. I wanted to find more Chemistry and Biology project ideas, specifically, and I love this website.
BUT I do have to admit it does go in depth, and it may not be what you're looking for. Sometimes, it has too much information for what I'm trying to do in the elementary schools, but I appreciate the information.
I think you'll recognize some of the projects in the future because I'm currently working to simplify them for the elementary level students.