20 Houston School District (Sundancer)
Houston School District (from the small town in Mississippi, not the large city in Texas) has competed in the World Solar Challenge before (though not in 2013), and has won the US High School Solar Car Challenge Open Division every year since 2001. Their solar car, Sundancer, is entered in the Adventure class at WSC 2015, competing against the Petroleum Institute from the UAE, TAFE South Australia, and Liberty Christian School. They maintain a blog at www.sundancersolarcar.blogspot.com. Good luck, team 20!
For up-to-date lists of all World Solar Challenge 2015 teams, see:
Update: added Instagram link.