Green Engineering in Solar Energy - Essay Example

Engineering and Construction 21 November Green Engineering in Solar Energy Overview of Solar Energy It is an alternativeenergy source with potential applications in most activities. In recent times, when environmental degradation and the increased costs of other fuels have become a concern for human life, solar energy that comes directly from the sun provides the most flexible option of a renewable energy source and is less costly in the long run. Solar energy is not new and has been used traditionally in most domestic operations like drying harvested food and clothes, lighting fire through proper reflections, and warming houses among others although it had some limitations. However, its past limitations for use in a broad range of applications has been eliminated through the use of advanced technology that enables better methods of capturing the energy, converting, and storing it for diverse uses. In the contemporary world, many people have installed the technologies to maximally benefit from solar energy. It is not only efficient, but a sustainable energy that can be relied on even in the future. The sun provides energy in two ways; by heating and through lighting. It radiates great amount of energy that travels through space and spreads all through the earth’s surface. Naturally, the inner core of sun produces the energy through a nuclear fusion of the hydrogen and helium atoms, radiates onto the sun’s surface, and consequently emits electromagnetic radiation onto the earth using a wide variety of wavelengths (“Alternative energy” kennesaw.edu). Upon reaching the earth surface, it is harvested for greater use in various processes. Solar energy is of great importance in supporting the life and processes of plants, as well as those of humans. Specific Aspects of how Solar Energy works There are two specific technologies of converting solar energy into electricity. These are the commonly known photovoltaic systems and solar thermal systems. They both employ very distinct mechanisms to produce power from the suns light. Photovoltaic energy This system of sunlight conversion uses solar panel technologies with the photovoltaic cells as the core element in generation of power (European communities 5). Solar panels are devices or modules of a connected assembly of photovoltaic cells, with the capability of collecting the sunlight photons for conversion. The solar panels are developed in different sizes of rectangular shape, from which several can be used as a combination to produce enough electricity. The solar cells in the panels are made up of semiconductor materials (silicon is very common), whose conductivity can be increased by introducing impurities (European communities 5). Basically, in the presence of light or sunshine, some of the radiant energy that hits PV cells is absorbed and transferred to the electrons within the atoms of the semiconductor. Because of the continuous transmitting energy from the sun, electrons of the cells tend to shift from their positions as they move towards a preferential side of attraction in the cells, creating an electric voltage that can be collected and channeled (“How do solar” nwwindandsolar.com). As the electrons move, they create space for others to move into, and hence generating the current in the electrical circuit (direct conversion of sunlight into electricity). Generally, once the energy as electricity is produced, the direct current generated and collected is converted through an inverter, into alternating current required to run most electronic appliances. The electricity can also be used by connecting the inverter to any load, or connect to the battery banks to store energy for further use. Suppose one switches into solar generated electricity using this technology, he has to enquire and seek suitable number and sizes of the solar panels that can be placed on the roof s, away from shade, and in a suitable position (South facing installations on the roof recommended), with correct angle inclinations to benefit from the sun’s energy and optimize green energy production. Solar thermal system Solar thermal involves a process of heating a medium to be used to run an engine that can generate electricity. Unlike photovoltaic, it requires parabolic shaped mirrors/troughs/ reflective surfaces to concentrate solar radiation to a specific location. Concentrating the sunlight into a focal point generates heat, which heats the medium (liquids like water, oil, compressed fluids, or special liquid salts, and gases like air, helium or nitrogen) filled in tubes to produce steam, which then powers the turbines or generators to create electricity (“Solar Thermal” solar-thermal.com). The solar collectors come in various technologies such as the solar dish and towers that track the sun or move with it to collect its energy, the Fresnal reflectors that work with atmospheric pressure or the common parabolic troughs. For domestic purposes, this technology is commonly used in heating water by collecting the suns heat and storing it in a tank for later use. For large production of electricity, the investment requires quite an extensive amount of space or land depending on the type of collectors’ technology and installation. How Solar Energy Fits with Green Engineering With current move to a global society, governments are encouraging investment in clean energy with fewer emissions of greenhouse gases. Solar energy has in its nature and conversion into electricity implemented the 1st principle of green engineering, by ensuring that the energy inputs and outputs in the process are inherently non-hazardous (Anastas and Zimmerman 96). Comparing solar and coal generated energy in plants, the processes used in the later generate a lot of carbon IV oxide, which is harmful to the ozone layers and global climate. Solar energy uses sun’s energy, which is less harmful and has non- hazardous effects. Despite the controlled chemicals, semiconductors, and impurities that are used, the energy input is clean and therefore removes the chances of harmful energy output. Solar energy is a renewable natural resource and its repetitive tapping and use does not deplete it or cause an ongoing environmental damage, as the fossil fuels do (Anastas and Zimmerman 100). The use of solar energy leads to a sustainable supply of electricity without affecting the overall value of the sun’s energy resource. The designs of solar panels and installation place into consideration the available space and solar panel efficiency, to maximize the overall return in the future. Solar panel systems come in various sizes and households can purchase suitable systems based on their entry level package (how many kilowatts). Hence, it is not a one size fit all, but separate solar panels which can be purchased and connected into a larger array, with a potential to supply all the electricity needs at a reduced power bill (Anastas and Zimmerman 99). Solar energy has a way of implementing reduced wastage in green engineering by reducing energy consumption. Through energy efficiency measures of solar energy enabled through green engineering, necessary energy use is optimized, while unnecessary energy is eliminated. The electricity can be stored in the connected batteries, or grid system, while the excess being processed can be used directly; hence incurring less costs and waste in the long run. The solar panels are designed for use in a certain viable time span, which defines their durability. Solar panels or collectors and systems and processes are designed to maximize energy, space, and time efficiencies (Anastas and Zimmerman 98). The solar cells in a single panel have the capacity to convert sunlight into specific amount electricity on their own, which when combined with others, improves the capacities. Fewer amounts of wavelengths that hit the cells are fully utilized and maximized into production. With the solar panels installations on the roofs of buildings, parabolic mirrors on the towers, or set up on the desert for large scale solar thermal power production, they are designed to maximize available limited space and solar energy that reaches them. Solar dishes and other reflective technologies are designed to shift with the changing direction of the sun, which are customs to maximize the time of energy concentration to a focal point. Strategic locations for installation of these equipments, like away from shades and often in the recommended south facing direction, or other suitable angle, is necessary in green engineering, so that the panels, concentrators, and systems are applied and used maximally, without necessarily wasting the resources throughout the life cycle. Works Cited “Alternative Energy: Solar Energy.” kennesaw.edu. n.d. Web. 21 November 2013. http://esa21.kennesaw.edu/activities/solar/solaractivity.pdf. Anastas, P.T. and J. B. Zimmerman. Through the 12 Principles of Green Engineering. 1 March 2003. Print European Communities. “Photovoltaic Solar Energy: Development and Current Research.” europa.eu. 2009. Web. 21 November 2013. http://ec.europa.eu/energy/publications/doc/2009_report-solar-energy.pdf. “How Do Solar Systems Produce Energy.” nwwindandsolar.com. n.d. Web. 21 November 2013 http://www.nwwindandsolar.com/solar-power-in-seattle-and-the-northwest/how-do-solar-systems-produce-energy/. . 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