This article provides an introduction to solar energy, including the different types of solar projects, the benefits and limits of solar energy and the federal and state programs that promote this technology. This article also discusses how the electricity produced by solar projects is typically sold and the challenges to the continued growth of this renewable resource.

For the US solar energy industry, 2011 represented a historic year. According to a report issued by the Solar Energy Industries Association (SEIA), a leading industry group, installed capacity of new solar photovoltaic (PV) reached 1,855 megawatts (MW) in 2011, a 109% increase from 2010 (see U.S. Solar Market Insight Report, SEIA, March 13, 2012 (SEIA Solar Report)).