Solar energy conversion

Solar energy conversion describes technologies devoted to the transformation of solar energy to other (useful) forms of energy, including electricity, fuel, and heat. It covers light-harvesting technologies including traditional semiconductor photovoltaic devices (PVs), emerging photovoltaics, solar fuel generation via electrolysis, artificial photosynthesis, and related forms of photocatalysis directed at the generation of energy rich molecules. Solar energy conversion describes technologies devoted to the transformation of solar energy to other (useful) forms of energy, including electricity, fuel, and heat. It covers light-harvesting technologies including traditional semiconductor photovoltaic devices (PVs), emerging photovoltaics, solar fuel generation via electrolysis, artificial photosynthesis, and related forms of photocatalysis directed at the generation of energy rich molecules. Fundamental electro-optical aspects in several emerging solar energy conversion technologies for generation of both electricity (photovoltaics) and solar fuels constitute an active area of current research. Solar cells started in 1876 with William Grylls Adams along with an undergraduate student of his. A French scientist, by the name of Edmond Becquerel, first discovered the photovoltaic effect in the summer of 1839. He theorized that certain elements on the periodic table, such as silicon, reacted to the exposure of sunlight in very unusual ways. Solar power is created when solar radiation is converted to heat or electricity. English electrical engineer Willoughby Smith, between 1873 and 1876, discovered that when selenium is exposed to light, it produced a high amount of electricity. The use of selenium was highly inefficient, but it proved Becquerel's theory that light could be converted into electricity through the use of various semi-metals on the periodic table, that were later labelled as photo-conductive material. By 1953, Calvin Fuller, Gerald Pearson, and Daryl Chapin discovered the use of silicon to produce solar cells was extremely efficient and produced a net charge that far exceeded that of selenium. Today solar power has many uses, from heating, electrical production, thermal processes, water treatment and storage of power that is highly prevalent in the world of renewable energy. By the 1960s solar power was the standard for powering space-bound satellites. Early 1970's solar cell technology became cheaper and more available ($20/watt). Between 1970 and 1990, solar power became more commercially operated. Railroad crossings, oil rigs, space stations, microwave towers, aircraft, etc. Now, houses and businesses all over the world use solar cells to power electrical devices with a wide variety of uses. Solar power is the dominant technology in the renewable energy field, primarily due to its high efficiency and cost-effectiveness. By the early 90's, photovoltaic conversion had reached an unprecedented new height. Scientists used solar cells constructed of highly conductive photovoltaic materials such as gallium, indium, phosphide and gallium arsenide that increased total efficiency by over 30%. By the end of the century, scientists created a special type of solar cells that converted upwards of 36% of the sunlight it collected into usable energy. These developments built tremendous momentum for not only solar power, but for renewable energy technologies around the world. Photovoltaics (PV) use silicon solar cells to convert the energy of sunlight into electricity. Operates under the photoelectric effect which results in the emission of electrons. Concentrated solar power (CSP) Uses lenses or mirrors and tracking devices to focus a large area of sunlight into a small beam. Solar power is anticipated to be the world's largest source of electricity by 2050. Solar power plants, such as Ivanpah Solar Power Facility in the Mojave Desert produces over 392MW of power. Solar projects exceeding 1 GW (1 billion watts) are in development and are anticipated to be the future of solar power in the US. The heat collected by the sun is highly intensive and radioactive. The sun bombards the earth with billions of charged nanoparticles with an immense amount of energy stored in them. This heat can be used for water heating, space heating, space cooling and process heat generation. Many steam generation systems have adapted to using sunlight as a primary source for heating feed water, a development that has greatly increased the overall efficiency of boilers and many other types of waste heat recovery systems. Solar cookers use sunlight for cooking, drying and pasteurization. Solar distillation is used for water treatment processes to create potable drinking water, which has been an extremely powerful player in providing countries in need with relief efforts through the use of advancing technology. Solar energy conversion has the potential to be a very cost-effective technology. Solar installations are becoming cheaper and more readily available to countries where energy demand is high, but supply is low due to economic circumstances. A 1 GW solar power plant can produce almost 10 times as much power as a fossil fuel combustion power plant that would cost twice as much to establish. Solar power plants have been projected to be the leader of energy production by the year 2050. Solar energy conversion has the potential for many positive social impacts, especially in rural areas that did not previously have grid-based energy access. In many off-grid areas, solar-electric conversion is the fastest growing form of energy procurement. This is especially true at latitudes within 45° north or south of the Equator, where solar irradiance is more constant throughout the year and where the bulk of the developing world's population live. From a health perspective, solar home systems can replace kerosene lamps (frequently found in rural areas), which can cause fires and emit pollutants like carbon monoxide (CO), nitric oxides (NOx), and sulfur dioxide (SO2) that adversely affect air quality and can cause impair lung function and increase tuberculosis, asthma, and cancer risks. In such areas, solar energy access has been shown to save rural residents the time and money needed to purchase and transport kerosene, thereby increasing productivity and lengthening business hours. In addition to energy access, these communities gain energy independence, meaning they are not reliant on a third-party electricity provider. The concept of energy independence is relatively new; for the vast majority of the 20th century, energy analyses were purely technical or financial and did not include social impact analysis. A 1980 study concluded that access to renewable energy would promote values conducive to larger societal benefit as opposed to personal promotion. While some academics argue that historically the parties in control of energy sources are those that create social hierarchies, this type of analysis became less “radical” and more mainstream after the introduction of technologies that enabled solar energy conversion.