Deadline: March 9, 2014
From the webpage:
The Department of Energy is awarding $100,000 in prizes for the best web and mobile applications that use one or more featured APIs, standards or ideas to help solve a problem in a unique way.
Submit an application by March 9, 2014!
Not much in the way of semantic integration opportunities, at least as the contest is written.
Still, it is an opportunity to work with government data and there is a chance you could win some money!