Energy Saving By Using Solar Panels Engineering Essay

Energy Saving By Using solar Panels Engineering EssayClimate transpose concerns, coupled with high oil prices, peak oil, and increasing g everywherenment support, ar driving increasing renewable null legislation, incentives and commercialization. New government spending, regulation and policies helped the pers constantlyance brave out the global financial crisis better than mevery otherwise sectors. Renewable pushing is ability that comes from natural re commencements much(prenominal) as sun dismountlight, wind, rain, tides, waves and geo thermal conflagrate, which atomic number 18 renewable be travail they be natur wholey replenished at a constant rate. About 16% of global final capacity consumption comes from renewables, with 10% coming from traditional biomass, which is generally workd for alter, and 3.4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 3% and are growing very rapid ly. The share of renewables in electricity generation is around 19%, with 16% of global electricity coming from hydroelectricity and 3% from new renewables. Since its emergence renewable vigor has come a long substance.In was not until the 1970s that environmentalists promoted the information of alternative ability both as a replacement for the eventual depletion of oil, as well as for an escape from dependence on oil it was at that stage that the first wind turbines appeared. On the other hand, solar had always been practised for warmthing and cooling, barely solar panels were too costly to build solar farms, until 1980.The reason why evolve chosen the topic of solar heating system systems solar slide fastener for my dissertation is beca accustom among the various renewable energy sources, solar energy is one of the crucial energy sources, if not the most crucial. According to a 2011 projection by the International Energy Agency, solar part generators whitethorn let o n most of the worlds electricity within 50 days, dramatically reducing the emissions of green domicil gases that harm the environment. Before doing this report, I hasten to admit that the knowledge that I had regarding solar energy or solar energy systems was minimal. But since get-go working on this report, I think, I cook come a long way yet, I have to admit, there has been done so much research in this field, in the past couple of decade that I would still have to go a long way before I would consider myself a specialist. This report should cater towards any individual who had heard of the solar energy, solar energy systems and how they could benefit from it. This report also gives a brief insight into, where solar energy system (solar energy) is headed in the approaching.A far as the social structure of my report is concerned, I will be looking into the history of solar energy, the solar energy itself, solar energy collectors solar panels Furthermore, I would also be looki ng at the benefits of solar energy systems for us and the consequences, if any. On the other hand, I would also be analysing economic issues related to solar energy systems such(prenominal) as the cost of heating a house or a create by the bureau of solar energy contra to contemporary means. Last further not the least I would be summarizing the advantages that I have discussed as well as look at few disadvantages, if there are any. I will sum up the whole report with a conclusion, thanks beforehand.History of solar energyBefore we delve into the discussion of why solar energy is so needed in the world today, well first look into what solar energy really is. By definition, solar energy is that glad light and heat that is aimd from the sun. Solar energy has been use by human beings since time immemorial.The radiation that comes from solar energy along with the resultant solar energized resources such as wave motive, wind, biomass and hydroelectricity all give an explanation fo r most of the accessible renewable energy that is present on earth. However, only an infinitesimal portion of the breathing solar energy is used.Solar energy has been used by humans for thousands of years. For example, ancient cultures used energy from the sun to keep warm by borrowing fires with it.Ancient Egyptians built places to live that allowed stored energy from the sun during the day, and a heat release during the night. This kind of architecture heated homes at night while memory the temperature low during the day buildings were designed so that, walls and floors collected solar heat during the day, that was released at night to keep them warm. If you have ever stood in the sun to get warm then you too have utilized solar thermal energy. Egyptians also used the sun as part of their mummification process, development the sun to dry dead bodies. The Egyptians used a form of passive voice solar power.3rd Century B.C., Greek soldiers with the help of Archimedes, focused lig ht on a Roman fleet by using mirrors. The Romans were invading a port city that did not have defenses ready for the attack. The mirrors were used to concentrate the energy of the sun, and cause the fleets sails to burn. The Romans retreated and the Greeks were able to rule out the invasion. The Greeks used passive solar power.100 A.D. a historical writer by the name of Pliny the Younger, built a house in the northern part of Italy that had mica windows in one room. This one particular room demonstrated solar heating in that its mica windows stored heat, and by and by gave it out. This room was useful because the added heat it generated less(prenominal)ened the amount of wood that had to be burnt, to maintain heat.Roman bath houses had famous south facing windows that heated the rooms. autochthonal Ameri shtupnisters also built houses that used passive solar power. Houses were built into the side of cliffs or hills to allow storage of heat during the day, and a release of heat at night.In 1767, the worlds first solar collector was built by Swiss scientist Horace de Saussare.They also kept their homes warm through passive solar energy designsThe stripping of p swelteringovoltaic happened in 1839 when the French physicist Edmond Becquerel first showed photovoltaic activity. Edmond had found that galvanising current in certain sensibles could be increased when exposed to light. 66 years later, in 1905, we gained an understanding of Edmonds work, when the famous physicist Albert Einstein clearly draw the photoelectric effect, the principle on which photovoltaic are based. In 1921 Einstein received the Nobel loot for his theories on the photoelectric effect.Solar carrells of operable use have been available since the mid 1950s when ATT Labs first developed 6% high-octane silicon solar cells. By 1960 Hoffman Electronics increased commercial solar cell efficiencies to as much as 14% and today, researchers have developed cells with more than 20% efficiencie s. 20% effective means that out of the total energy that hits the open air of a solar cell about 20% is converted into usable electricity.The first long-term practical application of PV cells was in satellite systems. In 1958 the Vanguard I, was launched into space. It was the first or arcseconding vehicle to be powered by solar energy. Photovoltaic silicon solar cells pop the questiond the galvanic power to the satellite until 1964 when the system was shut down. The solar power system was so successful that PVs have been a part of world-wide satellite space programs ever since. The sun provides endless nonpolluting energy to the satellite power systems and demand for solar cells has risen as a result of the telecommunications revolution and need for satellites.The energy crisis and oil embargos of the 1970s made many nations aware of their dependency on controlled non-renewable energy sources and this fueled exploration of alternative energy sources. This included further resear ch into renewable sources such as solar power, wind power and geothermal power.An economic breakthrough occurred in the 1970s when Dr. Elliot Berman was able to design a less dear(predicate) solar cell bringing the price down from $100 per watt to $20 per watt. This huge cost savings opened up a bulky number of applications that were not considered before because of high costs. These applications included railroads, lighthouses, off-shore oil rigs, buoys, and remote homes. For approximately countries and many applications, solar energy is now considered a primary energy source, not an alternative.Solar energySolar energy is the energy derived from the sun through the form of solar radiation. Solar powered electrical generation relies on photovoltaic and heat locomotives. A partial list of other solar applications includes space heating and cooling through solar architecture, day lighting, solar hot piddle, solar cooking, and high temperature process heat for industrial purposes . In my report, I would only be looking into a few of the above mentioned solar power reigning techniques, due to the fact that there is a limitation towards, how much material I can present in my dissertation.Solar cellA solar cell (also called a photovoltaic cell) is an electrical device that converts the energy of light necessitately into electricity by the photovoltaic effect. It is a form of photoelectric cell (in that its electrical characteristics e.g. current, voltage, or resistance vary when light is incident upon it) which, when exposed to light, can generate and support an electric current without being attached to any external voltage source. still solar or active solarSolar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, apportioning materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate.The Earth receives 174 petawatts (PW) of ledger entry solar radiation (insolation) at the upper atmosphere .Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earths surface is mostly spread across the visible and near-infrared tells with a small part in the near-ultraviolet.Earths land surface, oceans and atmosphere absorb solar radiation, and this raises their temperature. quick air containing evaporated body of piss supply from the oceans rises, causing atmospheric circulation or convection. When the air reaches a high altitude, where the temperature is low, pissing vapor condenses into clouds, which rain onto the Earths surface, completing the water cycle. The latent heat of water condensation amplifies convection, produci ng atmospheric phenomena such as wind, cyclones and anti-cyclones. Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14 C. By photosynthesis green plants convert solar energy into chemical energy, which produces food, wood and the biomass from which fossil fuels are derived.Yearly Solar fluxes Human Energy ConsumptionSolar3,850,000 crook2,250 EJBiomass3,000 EJPrimary energy use (2005)487 EJElectricity (2005)56.7 EJThe total solar energy absorbed by Earths atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour than the world used in one year. Photosynthesis captures approximately 3,000 EJ per year in biomass. The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from all of the Earths non-renewable resources of coal, oil, natural gas, and mined uranium combined Solar energy can be harnessed at incompatible levels around the world, mostly depending on outmatch from the equator.How solar power worksLight (photons) striking certain compounds, in particular metals, causes the surface of the material to emit electrons. Light striking other compounds causes the material to accept electrons. It is the combination of these two compounds that can be made use of to cause electrons to flow through a conductor, and thereby create electricity. This phenomenon is called the photo-electric effect. Photovoltaic means cheer converted into a flow of electrons (electricity)..Passive solar heatingIn passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design or climatic design because, unlike active solar heating systems, it doesnt involve the use of mechanical and electrical devices.The key to designing a passive so lar building is to best take advantage of the local climate. Elements to be considered include window placement and glazing type, thermal insulation, thermal mass, and shading. Passive solar design techniques can be applied most easily to new buildings, but existing buildings can be adapted or retrofitted.http//www.iklimnet.com/save/eco_images/five_elements_passive.gifPassive energy gainPassive solar technologies use sunlight without active mechanical systems (as contrasted to active solar). Such technologies convert sunlight into usable heat (water, air, and thermal mass), cause air-movement for ventilating, or future use, with little use of other energy sources. A common example is a solarium on the equator-side of a building. Passive cooling is the use of the said(prenominal) design principles to reduce summer cooling requirements.Some passive systems use a small amount of conventional energy to control dampers, shutters, night insulation, and other devices that enhance solar en ergy collection, storage, and use, and reduce undesirable heat transfer.Passive solar technologies include direct and indirect solar gain for space heating, solar water heating systems based on the thermo siphon or geyser pump, use of thermal mass and phase-change materials for slowing indoor air temperature swings, solar cookers, the solar chimney for enhancing natural ventilation, and earth sheltering.More widely, passive solar technologies include the solar furnace and solar forge, but these typically require some external energy for aligning their concentrating mirrors or receivers, and historically have not proven to be practical or cost effective for widespread use. Low-grade energy needs, such as space and water heating, have proven, over time, to be better applications for passive use of solar energy.Pragmatic approach to a productive passive solar energyMany detached suburban houses can achieve reductions in heating expense without obvious changes to their appearance, comfo rt or usability. This is done using good siting and window perplexing, small amounts of thermal mass, with good-but-conventional insulation, weatherization, and an occasional supplementary heat source, such as a central radiator connected to a (solar) water heater. Sunrays may fall on a wall during the daytime and raise the temperature of its thermal mass. This will then radiate heat into the building in the evening. This can be a problem in the summer, especially on western walls in field of honors with high degree day cooling requirements. External shading, or a refulgent barrier plus air gap, may be used to reduce undesirable summer solar gain.Active solar heating systemsActive solar technologies are employed to convert solar energy into another more useful form of energy. This would normally be a conversion to heat or electrical energy. Inside a building this energy would be used for heating, cooling, or off-setting other energy use or costs. Active solar uses electrical or mechanical equipment for this conversion. Solar energy collection and utilization systems that do not use external energy, such as a solar chimney, are classified as passive solar technologies. Passive solar relies on the inherent thermo-dynamic properties of the system or materials to operate. They do not need external energy sources.httphttps://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPiYSa4XDMPdiyMUf3cP1SmXMrWVP1vYknu4qslRMbXcBAsG-rm4DSg1wO5yZFhaBoUFGQf_XRmRTw236gZVb7a366CwNUf4RGXeLOLKI3q-QKHGEHO2Vu0ZCz2T7Pql1UU-mEkR5esRdJ/s1600/active-solar-heating.jpgSolar hot water systems, except those based on the thermo siphon, use pumps or fans to circulate fluid (often a mixture of water and glycol to prevent freezing during winter periods) or air, through solar collectors, and are therefore classified under active solar technology.The basic benefit of active systems is that controls (usually electrical) can be used to maximize their effectiveness. For example a passive solar thermal array which does not rely on pumps and sensors will only start circulating when a certain amount of internal energy has built up in the system. Using sensors and pumps, a relatively small amount of energy (i.e. that used to power a pump and controller) can harvest a far spaciousr amount of available thermal energy by shimmy on as soon as a useful temperature differential becomes present. Controls also allow a greater variety of choices for utilizing the energy that becomes available. For example a solar thermal array could heat a swimming pool on a relatively cool morning where heating a internal hot water cylinder was impractical due to the different stored water temperatures. Later in the day as the temperature rises the controls could be used to switch the solar heated water over to the cylinder instead.The downside to Active Solar systems is that the external power sources can fail (probably rendering them useless), and the controls need maintenance.How to buy solar panels solar water heatingShowerSolar water heating can meet about a third of your hot water needs, research conducted by a UK research magazine.A solar water heating system (also known as solar thermal system) uses panels fitted to your roof to heat water for use around the home.A typical solar hot water system is able to meet around a third of a households hot water needs a saving of 55 to 80 on your annual water-heating bills, based on a three-bedroom semi-detached house.Householders installing solar water heating systems can get 300 through the governments Renewable Heat Incentive Premium Payment scheme.Choosing a solar water heating systemWhen choosing a solar water heating system, youll need to consider four major factorsyour average hot water usethe field of force of south-facing roof availableyour existing water heating systemyour budget.Youll need roughly one square meter of collector area per person in the household. each metre of panel area will need between 30 and 60 litres of water tank car volume.If you use a less efficient collector (such as flat-plate solar water heating panels), youll need to co ver a larger area than if you use a more efficient collector (such as evacuated tubes).Youll also need to select system components (such as a hot water cylinder, controls and pipe work) and choose the location for your solar panels, considering shade, pipe runs, roof pitch and future access.Solar water heating installationThere are plenty of solar panel installers out there, so I recommend that you always collect a range of quotes to compare.Cost effectiveness of solar water heating systemsIn my opinion developing common industry standards and offering public incentives is important. He emphasizes that creating public sentience programs is the key to having success in this industry, including a cleaner environment and more jobs as a consequence.It is clear that installing the application is easy for households since the technology is less complicated and cheaper than PV. According to The Solar Guide, the payback period for an investment in a solar water heating system is 3 to 5 yea rs, although it may vary a lot in different countries due to national standards and differences in manufacturing quality.The return of investment depends on the system and the current fuel source that is being used to heat the water. It makes more sense to install a combi-system (hot water+space heating) whereby a 12-20 sq-m would completely cover a households water heating demand and a substantial part of its space heating demand in spring and in autumn.http//upload.wikimedia.org/wikipedia/commons/ thumb/f/f7/SolarTrackerRoofView300W200H.jpg/220px-SolarTrackerRoofView300W200H.jpgSolar trackers may be driven by active or passive solar technologyMost solar collectors are fixed in their array position mounting, but can have a high performance if they track the path of the sun through the sky (however it is unusual for thermal collectors to be attach in this way). Solar trackers, used to orient solar arrays may be driven by either passive or active technology, and can have a signific ant gain in energy yield over the course of a year when compared to a fixed array. Again passive solar tracking would rely on the inherent thermo-dynamic properties of the materials used in the system rather than an external power source to generate its tracking movement. Active Solar Tracking would utilize sensors and motors track the path of the sun across the sky. This action can be caused by geographical and time data being programmed into the controls. However, some systems actually track the brightest point in the sky using light sensors, and manufacturers claim this can add a significant extra yield over and above geographical tracking.How does Solar Thermal work?The basic mechanism of solar thermal energy is to collect the solar radiation and transfer the heat directly or indirectly to its final destination via a heat transfer medium usually a fluid.The most commonly used applications are Domestic Hot water (DHW), Combined DHW and Space Heating, District Heating, Solar Cool ing and Air-Conditioning. High Temperature Solar Thermal Electricity Generation is also among solar thermal applications. (e.g. solar tower and parabolical through applications).The key component of the solar thermal systems is the collectors which can be divided into two groupsUnglazed collectors have been used in the industry for a long time, mainly for heating open-air swimming pools. There is no heat exchanger in the system, and the water is flowing directly through long thin tubes. It is cheap and easy to install. Due to the simplicity of unglazed collectors, they cannot fulfill the needs for delivering full-time energy. Unglazed collectors are mainly used in the USA and in Australia.Glazed collectors are much more efficient in supplying continuous heating and achieving higher temperatures than unglazed ones. Glazed collectors are usually rectangular boxes covered by glass, containing little pipes and tubes and a heat absorbing material inside. There are different types of col lectors for different means of use. Glazed collectors are commonly used in China, Europe and the Middle East.Solar thermal collectorA solar thermal collector is a solar collector designed to collect heat by absorbing sunlight. The term is applied to solar hot water panels, but may also be used to denote more complex installations such as solar parabolic, solar trough and solar towers or simpler installations such as solar air heat. The more complex collectors are generally used in solar power plants where solar heat is used to generate electricity by heating water to produce steam which drives a turbine connected to an electrical generator. The simpler collectors are typically used for supplemental space heating in residential and commercial buildings. A collector is a device for converting the energy in solar radiation into a more usable or storable form. The energy in sunlight is in the form of electromagnetic radiation from the infrared (long) to the ultraviolet (short) wavelengt hs. The solar energy striking the Earths surface depends on weather conditions, as well as location and orientation of the surface, but overall, it averages about 1,000 watts per square meter under clear skies with the surface directly perpendicular to the suns rays.A solar collector works to convert and concentrate solar energy into a more usable form. For example, a thermal collector may use a parabolic array of mirrors to focus, direct, and reflect the light of the sun to a smaller point where the heat can be used to drive some sort of turbine engine by heating the driving fluid. Another type of collector may use a flat panel array of solar photovoltaic cells to convert solar energy directly into electricity. Some metals exhibit a photoelectric property whereby when the metal is exposed to light, it causes electrons to be emitted. These metals may be arranged in a valence-covalence band configuration which generates the actual voltage within the array.Types of solar collectors f or heatSolar collectors fall into two general categories non-concentrating and concentrating. In the non-concentrating type, the collector area (i.e., the area that intercepts the solar radiation) is the same as the absorber area (i.e., the area absorbing the radiation). In these types the whole solar panel absorbs the light.Flat-plate and evacuated-tube solar collectors are used to collect heat for space heating, domestic hot water or cooling with an absorption chiller.Types of solar collectors for electricity generationParabolic troughs, dishes and towers described in this section are used almost exclusively in solar power generating stations or for research purposes. Although simple, these solar concentrators are sooner far from the theoretical maximum concentration. For example, the parabolic trough concentration is about 1/3 of the theoretical maximum for the same acceptance angle, that is, for the same overall tolerances for the system. Approaching the theoretical maximum may be achieved by using more elaborate concentrators based on non-imaging optics.Parabolic troughhttp//upload.wikimedia.org/wikipedia/commons/thumb/b/b5/Parabolic_trough.svg/250px-Parabolic_trough.svg.pngParabolic toroughThis type of collector is generally used in solar power plants. A trough-shaped parabolic reflector is used to concentrate sunlight on an insulated tube (Dewar tube) or heat pipe, placed at the focal point, containing coolant which transfers heat from the collectors to the boilers in the power station.Parabolic dishhttp//upload.wikimedia.org/wikipedia/commons/thumb/1/12/Parabolic-dish.jpg/220px-Parabolic-dish.jpghttp//bits.wikimedia.org/static-1.21wmf3/skins/common/images/magnify-clip.pngSolar Parabolic dishIt is the most powerful type of collector. One or more parabolic dishes concentrate solar energy at a single focal point, -similar to a reflecting telescope which focuses starlight, or to a dish antenna used to focus radio waves. This geometry may be used in solar f urnaces and solar power plants.There are two key phenomena to understand in order to comprehend the design of a parabolic dish. One is that the shape of a parabola is defined such that incoming rays which are parallel to the dishs axis will be reflected toward the focus, no matter where on the dish they arrive. The second key is that the light rays from the sun arriving at the Earths surface are almost completely parallel. So if the dish can be line up with its axis pointing at the sun, almost all of the incoming radiation will be reflected towards the focal point of the dish-most losses are due to imperfections in the parabolic shape and imperfect reflection.Losses due to atmosphere between the dish and its focal point are minimal, as the dish is generally designed specifically to be small enough that this factor is insignificant on a clear, sunny day. Compare this though with some other designs, and you will see that this could be an important factor, and if the local weather is hazy, or foggy, it may reduce the efficiency of a parabolic dish significantly.In dish-stirling power plant designs, a Stirling engine coupled to a dynamo is placed at the focus of the dish, which absorbs the heat of the incident solar radiation, and converts it into electricity.(Solar) Power towerA power tower is a large tower surrounded by tracking mirrors called heliostats. These mirrors align themselves and focus sunlight on the receiver at the top of tower, collected heat is transferred to a power station below.AdvantagesVery high temperatures reached. High temperatures are capable for electricity generation using conventional methods like steam turbine or some direct high temperature chemical reaction.Good efficiency. By concentrating sunlight current systems can get better efficiency than simple solar cells.A larger area can be covered by using relatively inexpensive mirrors rather than using expensive.Concentrated light can be redirected to a suitable location via. For exam ple illuminating buildings.Heat storage for power production during cloudy and overnight conditions can be accomplished, often by underground tank storage of heated fluids. Molten salts have been used to good effect.DisadvantagesConcentrating systems require sun tracking to maintain Sunlight focus at the collector.Inability to provide power in diffused light conditions. Solar Cells are able to provide some output even if the sky becomes a little bit cloudy, but power output from concentrating systems drop drastically in cloudy conditions as diffused light cannot be concentrated passively.Solar panelA solar panel (also solar module, photovoltaic module or photovoltaic panel) is a packaged, connected assembly of photovoltaic cells. The solar panel can be used as a component of a larger photovoltaic system to generate and supply electricity in commercial and residential applications. Each panel is rated by its DC output power under standard test conditions, and typically ranges from 10 0 to 320 watts. The efficiency of a panel determines the area of a panel given the same rated output an 8% efficient 230 watt panel will have twice the area of a 16% efficient 230 watt panel. Because a single solar panel can produce only a limited amount of power, most installations contain multiple panels. A photovoltaic system typically includes an array of solar panels, an inverter, and sometimes a battery and or solar tracker and interconnection wiring.Theory and constructionSolar panels use light energy (photons) from the sun to generate electricity through the photovoltaic effect. The majority of modules use wafer-based crystalline silicon cells or thin-film cells based on candle telluride or silicon. The structural (load carrying) member of a module can either be the top layer or the back layer. Cells must also be protected from mechanical damage and moisture. Most solar panels are rigid, but semi-flexible ones are available, based on thin-film cells.Electrical connections are made in serial to achieve a desired output voltage and/or in parallel to provide a desired current capability. The conducting wires that take the current off the panels may contain silver, copper or other non-magnetic conductive transition metals. The cells must be connected electrically to one another and to the rest of the system. Externally, hot terrestrial usage photovoltaic panels use MC3 (older) or MC4 connectors to facilitate easy weatherproof connections to the rest of the system.Bypass diodes may be incorporated or used externally, in case of partial panel shading, to