On the other hand the sun is a major source of inexhaustible free energy (i.e., solar energy) for the planet Earth. Currently, new technologies are being employed to generate electricity from harvested solar energy. These approaches have already been proven and are widely practiced throughout the world as renewable alternatives to conventional non hydro technologies. Theoretically, solar energy possesses the potential to adequately fulfill the energy demands of the entire world if technologies for its harvesting and supplying were readily available. Nearly four million exajoules (1 EJ = 1018J) of solar energy reaches the earth annually, ca. 5 × 104 EJ of which is claimed to be easily harvestable. Despite this huge potential and increase in awareness, the contribution of solar energy to the global energy supply is still negligible. Another major prospect with regard to solar research is associated with the current drive toward reducing global carbon emissions, which has been a major global environmental, social, and economic issue in recent years. For example, 696,544 metric tons of CO2 emissions have been reduced or avoided via the installation of 113,533 household solar systems in California, USA. Therefore, the adoption of solar technologies would significantly mitigate and alleviate issues associated with energy security, climate change, unemployment, etc. It is also anticipated that its use will play an important role within the transportation sector in the future as it does not require any fuel transportation. This will help us expand our understanding on how much further we can count on solar energy to meet the future energy demand.