This paper carries out a comparative study of photovoltaic solar energy in the United States and Brazil. This study takes into account aspects such as solar radiation and government incentives for using this renewable energy source. In addition, at the beginning of the paper, a comparison is made of the evolution of solar energy in these two countries. This helps the reader to contextualize and understand the current scenario of solar energy development, both in the United States and in Brazil. Following this analysis, a solar energy system and its main components are described in detail. Finally, the energy policies of each country are outlined, showing how this influences their development in the use of this renewable energy source.