Harnessing the sun's rays for optimal cost-effectiveness, appeal and design pushes university teams across the country to construct a solar-powered house with the best technology in the world. This has happened biennially since 2002 through the U.S. Department of Energy's Solar Decathlon challenge.

In 2013, 20 more teams will take on the challenge of creating a solar-powered home in Orange County Great Park in Irvine, Calif. But the competition is getting tougher, double the applications were sent in this year.

Meet the 20 teams competing this year:

• Arizona State University and The University of New Mexico (Tempe, Ariz., and Albuquerque, N.M.)
• Czech Technical University (Prague, Czech Republic)
• Hampton University and Old Dominion University (Hampton and Norfolk, Va.)
• Middlebury College (Middlebury, Vt.)
• Missouri University of Science and Technology (Rolla, Mo.)
• Norwich University (Northfield, Vt.)
• Queens University, Carleton University, and Algonquin College (Kingston and Ottawa, Ontario, Canada)
• Santa Clara University (Santa Clara, Calif.)
• Southern California Institute of Architecture and California Institute of Technology (Los Angeles, Calif.)
• Stanford University (Palo Alto, Calif.)
• Stevens Institute of Technology (Hoboken, N.J.)
• The Catholic University of America, George Washington University, and American University (Washington, D.C.)
• The University of North Carolina at Charlotte (Charlotte, N.C.)
• The University of Texas at El Paso and El Paso Community College (El Paso, Texas)
• University of Calgary (Calgary, Alberta, Canada)
• University of Louisville, Ball State University and University of Kentucky (Louisville, Ky.; Muncie, Ind.; and Lexington, Ky.)
• University of Nevada Las Vegas (Las Vegas, Nev.)
• University of Southern California (Los Angeles, Calif.)
• Vienna University of Technology (Vienna, Austria)
• West Virginia University (Morgantown, W.V.)

Before teams even start building, their proposal is reviewed by scientists, engineers and experts in the field. In 2011, 20 teams made the cut. The student teams spend two years designing and building their home that will be metered for energy production and efficiency.

Once the competition ends, the houses are sold to recover costs and raise money for future teams or are used for further research. Check out the map to see all of the past locations.

View U.S. Department of Energy Solar Decathlon Houses in a larger map