Energy from the sun is a highly sustainable source adopted by many countries around the world. The United States is one of the top countries generating solar power, ranking fourth after China, Germany and Japan. The range of solar installation is wide and includes both the industrial and the private sector. Most popular is the use of rooftops for solar power generation, but utilities, manufacturers and other institutions also increasingly generate solar power.
The most solar power systems installed are in California, Arizona, and Massachusetts. When it comes to generation capacity, California also leads, followed by New Jersey and Massachusetts. California requires utilities to generate one third of their electricity from renewable energy sources by 2020.
Photovoltaic power generation has grown with a rapid pace and is projected to continue its growth in many states as the cost for producing solar panels has gone down significantly, partly because of highly efficient tools to monitor solar cell production. Many manufacturers and researchers refer to k-Space, a leading supplier of analysis tools, that measure thin-film deposition rate, stress, and surface roughness in real time. It is estimated that by 2025, approximately 10 percent of power generated in the United States will come from solar energy.