The Apps for Energy II contest, which is the second contest in the year-long American Energy Data Challenge, will encourage contestants to leverage ideas developed during the American Energy Data Challenge's first contest, and to use open data sources. As part of the contest, the Energy Department will host a series of "hackathons" in four cities to create venues where people can brainstorm, collaborate, and begin creating apps that use publicly-available data to solve problems. The hackathons will be in Washington, D.C., January 24-25; San Diego, California, January 31-February 1; Valley Forge, Pennsylvania, February 7-8; and Boston, Massachusetts, Feb. 15-16. Contestants will be eligible to win prizes at the events and by submitting their apps for judging as part of the nationwide contest.