Electrical Energy EngineeringThe harvesting of energy is high priority for the benefit of humankind. Coal surpassed wood as the dominant source for energy in the U. S. about 1888. In turn, petroleum passed up coal in about 1950. National attention is increasingly being focused beyond these non renewable sources to include a diverse set of renewable energy sources. The ultimate primary source for all of these energy sources, whether non renewable or renewable, is the Sun.