I have a very distinct memory of tv telling me, “every hour the sun beams enough solar energy to power our planet for a year.” Solar power, however, has yet to deliver on this promise from my children’s television. Why is it so hard???? The sun shines on us every day, it comes down here we gather it up and we use it for energy — boom boom boom, done! But it’s slightly more complicated than that, as you know. In 1873, electrical engineer Willoughby Smith discovered the element selenium was photoconductive — when exposed to sunlight the metallic form of selenium becomes a semiconductor! Three years later, other scientists discovered selenium could be used to create electricity from sunlight — dubbed the photoelectric effect. When sunlight hits a metal like selenium the electromagnetic radiation is absorbed into it — this fueled a whole HOST of physics nerds who are still arguing whether light is a particle or a wave to this day! It was such a big deal the 1921 Nobel Prize in physics was awarded to Albert Einstein for explaining the photoelectric effect, and for his contributions to theoretical physics… or whatever.
Eventually, scientists discovered that the light energy causes the freeing of electrons which, if captured, could be used to generate electricity!. This photoelectric effect has since been cultivated and researched and cultivated again, and the discovery that many different elements display a photoelectric effect opened it up for use in a number of inventions! Photosensitive cells are used in televisions, industrial processes, telecommunications, fiber optics, copy machines, spectroscopy and telescopy, and to sense pollution or emphasize other lights like in night vision or infrared cameras; plus, of course, solar panels via a photovoltaic cell. Photovoltaics were invented in the 1950s, and were popularized by the space program as a way to power satellites. In the 1970s, pushes were made to modernize photovoltaics for use in commercial and residential power — but consumers mainly used them for calculators, watches, radios and the like. Like a battery, a photovoltaic cell has a positive and negative to guide the electrons into the system. Each cell uses a pair of silicon wafers — one doped with phosphorous (negative) and one with boron (positive).
From 1995 to 2010 solar energy use grew 20 percent a year — and now, new inventions are making it even more affordable. Firstly, in 2009, China created way more solar panels than the market needed, and the price collapsed. And secondly, state and federal governments in the United States, Germany, the United Kingdom and Japan are all giving subsidies to cultivate better renewable energy systems. This means more supply and demand for this technology, and as money flows through renewables, they get better! Recently the University of Queen Mary in London revealed they can turn shrimp shells into cheap solar panels. The shells of crustaceans contain chitin and chitosan which can be extracted into CQD or carbon quantum dots — CQD solar cells aren’t new, but usually use expensive ruthenium for its photoelectric properties. Instead, the researchers found this biomass byproduct of the shrimp industry can be used to extract CQDs and create fully renewable, cheap solar cells! Pretty cool, huh? Fortunately solar cells aren’t the only place finding greener solutions for energy use — Toyota is, too! The new Toyota Mirai is looking to the future with sustainability in mind; fueled by hydrogen and leaving zero emissions behind.
As found on Youtube