Outside of the three scenarios above, solar energy usually requires a little human input to really work (photosynthesis, which helps grow crops for food and fuel, is a notable exception). This help can come in lots of different forms, from architecture and urban planning, which uses techniques to maximize light and heat from the sun to our benefit in our buildings, to solar thermal, the most widely used category of solar energy technology, including solar cooking, water distillation and purification and lots more, to heating water for our use and desalination.
But, by far, solar energy’s most talked-about use is electricity generation. For now, photovoltaic (PV) cells and panels remain the most-used method for turning sun into electricity. Basically, photovoltaics cause photons from sunlight to knock electrons into a higher state of energy, creating electricity. Photovoltaic production has been doubling every two years, increasing by an average of 48 percent each year since 2002, making it the world’s fastest-growing energy technology.
But it’s not alone in the solar world; concentrating solar systems use lenses, mirrors and tracking systems to focus a large area of sunlight into a small, concentrated beam, which is then used to generate electricity. This can be accomplished using a trough system; by allowing direct sunlight to hit troughs, the solar collectors concentrate it into a single area that boils liquid in order to make steam, which in turn moves turbines to make electricity. This up-and-coming technology can be made even more efficient with the use of a solar tower, which is just what it sounds like: a tower that uses careful sun tracking to concentrate solar energy near its top. There are various other technologies that can create solar power from solar energy, but, for now, these remain the most popular and most viable.