California, the third-largest state in the United States in land size, is known for offering a major concentration of jobs in business services, education, government, leisure, and transportation. California consistently places among the top 10 economies in the entire world, and also has a significant agricultural and computer industry. Two nuclear power plants, San Onofre Nuclear Generating Station and Diablo Canyon Nuclear Power Plant, comprise a number of jobs and create output of about 20 percent of the entire state's energy. Jobs are also provided through California's progressive explorations of alternative energy sources, such as wind, solar energy, geothermal, and wood.