Tapping the power of the sun will be the theme of the U.S. Department of Energy’s National Renewable Energy Laboratory’s Junior Solar Sprint “Solarbrate” event May 10. Visitors will see participating students race solar cars and build solar models using K’NEX construction toys. For the Junior Solar Sprint, each team starts with a motor and a silicon solar cell. Using any other materials, competitors design and build vehicles no larger than 12 inches wide, 24 inches long and 12 inches high. Five design awards will be given for technology, craftsmanship and innovation.