The depleting oil reserves with estimates of oil reserves peaking in a decade or two, the specter of global warming and the air pollution has lead the world community to seek hydrogen economy. The presentation will review the global energy sources, needs and outlook. The role of various sources of energy including fossil fuels, renewable sources, and nuclear are examined in the equation of hydrogen economy. The technical and social challenges associated with the hydrogen economy and its impact on global market is discussed. The talk will also review current road maps towards reaching hydrogen economy in US and around the globe.