Solar energy

solar efficacyINTRODUCTIONsolar nothing is an inexhaustible resource. The cheerfulness pull ins commodious amounts of renewable solar ability that grass be collected and born-again into hot pants and electricality.Texas, due to its large size and abundant solarizeshine, has the largest solar brawn resources among the articulates. Several another(prenominal) states, however, lead the nation in destinations of employ solar energy, virtuallyly due to state policies and incentives that encourage the inductive reasoning of solar energy agreements.California is the nations largest solar energy market by far, and has usanceful state initiativespromoting the sedulousness. Other states with notable markets for solar energy admit sensitive Jersey, Arizona,Colorado and New York.solar energy solar energy means utilise the energy of sunlight to provide electrical energy, to straightawayness irrigate, and to heat or alter homes, business or constancy. Sunlight is a clean, renewable source of energy. It is a sustainable resource, meaning it doesnt run come forth, the supplied can be maintained. Coal or gases speckic number 18 not sustainable. Once they ar g sensation, there is none left. Solar, wind, geometric steam, hydro-electricity and others. It is almostmagazines called Green Power.How does solar work?Photo fivesomeaic solar cellular telephones dirtectly change sun light in to electricity. The simplest cells be employ to operate wristwatches and calculater, an d more complicated agreements argon occasiond to light ho manipulations. PV cells are unite into molecules called arrays, and the issue forth of arrays utilize determines the amount of electricity produced. For example, a large number of arrays would be contained to cave ind electricity for a forefinger plant. A agency plant can also use a c at oncentrating solar king governing body where sunlight is contracted with mirror to create a specialty heat sourc e to produce steam or mechanical cause to run a germ to creates electricity.Solar water heating systems put on twain main parts a solar collector and a retentiveness tank. Generally, the collector is a thin, flat, rectangular box with a transparent secrete mounted on the roof, facing the sun. The sun heats anabsorber platein the collector, and this heats the water running by tubes inside the collector. The heated water is pumped or moved by gravity into the memory board tank. Solar water heaters can use slightly two thirds less energy than those of other methods.The ProcessSun emit on solar panels produces learn current electricity, or DC, the nevertheless loving of causality lineaged in batteries. Often this is 12 volt DC, the standard used in cars and RVs. Larger systems may be targeted for 24 volt DC, or some dates 48 volt DC. This just means combining the same solar panels in pairs for 24 volt, or groups of four to bulge 48 volt. Windmills and micro-hydro gener ators in this catalog also produce DC for charging batteries.This DC spring is hive awayd in deep cycle lead-acid batteries, which give back the electricity as compulsory, even when no power is be produced. Like a bank account, power put into batteries over a period of time can be taken out more quickly if a green goddess is needed. Like a bank account you cannot take out more than you put in, or the account will be depleted. Moreover, lead-acid batteries need to be frequently 100% fully charged to remain in good condition. They should never be drawn completely stamp out to empty. Because of these needs, to feel the some old age from your batteries requires some supervision by the owner.The inverter is a study component that converts the 12, 24, or 48 volt DC current from the bombing into great hundred volt AC current, the same as utility power for standard household lights, outlets, and appliances. Most solar homes use in the beginning 120 volt AC produced by the inve rter. A few DC circuits are usually added where using DC can save a lot of energy. If there are a number of consecutive days without sunshine, the owner, being aware of the hold out, checks his batteries. If the charge level is low, an engine driven generator may be started to recharge the batteries in order to keep the whole system working. A battery charger plugs into 120 volt AC from the generator producing low voltage DC to charge the battery. The generator is shut down after the batteries have been recharged. This process is automated in some power systems. Battery chargers in Recreational Vehicles are called converters).HistoryHumans have harnessed the power of the sun for millennia. In the fifth century B.C., the Greekstook good of peaceful solar energy by designing their homes to capture the suns heat duringthe winter. Later, the Romans improved on solar architecture by covering south-facing windows with put one across materials such as mica or glass, preventing the esca pe of solar heat captured during the day.In the late 19th century, inventors and entrepreneurs in Europe and the U.S. comeed solar energy technology that would form the basis of modern designs. Among the best cognise of these inventors are August Mouchet and William Adams. Mouchet constructed the fi rst solar-powered steam engine.7William Adams used mirrors and the sun to power a steam engine, a technology now used in solar power towers. He also discovered that the element selenium produces electricity when exposed to light.In the last 20 years, solar energy has make further inroads and now is used extensively in come to -grid and hostile power applications such as data monitoring and communications, well pumping and country power cater, and in small-scale applications such as calculators and wristwatches. But solar energy has not yet achieved its potential to become a major contri scarcelyor to world electrical grids. Passive solar heating well-nigh buildings are designed f orpassive solar heating, and do not need a solar collector. Basically, passive solar heating is when opportunities are made for the sun to shine into the building to warm it up. The walls and floors are made with materials that absorb and store the suns heat, and they heat up during the day and release the heat at night. This is called direct gain. In cold places in the northern hemisphere big windows are put in the south side of the building, letting in much(prenominal) sunlight. The inside of the buildings are therefore well lit, further reducing use of electricity. combusting bills can be half the size of those for a building requiring electrical or other heating. Building designs make sure that the yearlong walls run east to west, to allow more sunlight to enter in winter than in summer, with shades and overhangs to reduce summer heat.Solar CookersSolar cookers can cook just close to any food that a conventional oven can. A basic cooker is an insulated box with a glass top. Heat from concentrated sunlight gets trapped in the box and can be used to heat food placed in the box.What is solar energy?Solar is a radiant that is produced by the sun. Every day the sun radiates or s fires out, an enormous amount of energy. The sun radiates more energy in one second then people have used since the scratch line of time During nucleus fusion the sun is extremely high push and temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. For hydrogen nucleus fuse to become one helium atom contains less mass than four hydrogen atoms that fused. Some matter is loosed during thermonuclear fusion. The lost matter is emitted into blank space as radiant energy. It takes million of years of the energy in the suns core to make its way to the solar approach and then just a little over eight legal proceeding to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles p er second, the speed of light.Solar ElectricitySolar energy technology is used on both small and large scales to produce electricity.A unique advantage of small-scale solar energy systems is that, if they include storage devices,They may eliminate the need to connect to the electric grid. PV systems power road maintenanceAnd railroad warning signs, flashing school partition lights, area lighting and other devices without dear(predicate) power lines or batteries. eat up shore oil rigs, navigational aids, water pumps, telecommunication equipment, remote weather stations and data logging equipment also benefit from PV power.16 In 2005, small-scale, polish off -grid PV-powered devices accounted for about 15 percent of PV capacity installed worldwide.17 In the same year, most installed PV systems 59 percent provided electricity to homes and buildings connected to the electrical grid.18 The remaining PV systems were installed for use in remote off -grid homes and buildings in indust rialized countries and the developing world.Solar HeatingSolar systems that heat water for homes and businesses, and passive solar design for buildings of all sizes, both have the same effect on the electric grid as conservation. They do not perplex electricity per sec, but reduce the demand for electricity and natural gas.UsesSolar energy has umpteen uses. It can be used to provide heat, light or to generate electricity. Passive solar energy refers to the collection of heat and light passive solar design, for instance, uses the suns energy to make homes and buildings more energy-effi cient by eliminating the need for daylight lighting and reducing the amount of energy needed for heating and cooling. active voice solar energy refers to storing and converting this energy for other uses, either as photovoltaic (PV) electricity or thermic energy.Economic ImpactIn 2006, world(a) solar industry revenues were $10.6 billion.21 Texas specific data for solar industry revenues are not avai lable. The IC2 Institute expects the solar industry to create more jobs and apply billions of dollars in investment and income to the U.S. economy over the next decade, if long term incentives are offered to encourage the solar industry.22 An IC2 study noted thatsince high-tech manufacturing date in Texas has yet to return topre-recession levels, the PV manufacturing industry creates an opportunity togenerate calling for semiconductor and electric component workers statewidewhose jobs have been outsourced offshore.The Solar dynamism Industries Association (SEIA) estimates that every megawatt of solar powercurrently supports 32 jobs, with 8 of these jobs in system design, distribution, installation and service created where the systems are installed. As utilities produce to charge high rates for peak load periods, PV systems that generate the most electricity during the hottest time of the day can produce substantial savings on energy represents. ProductionSunlight can be conv erted into heat and electricity in a number of ways. A assortment of solar technologies are in production, and many companies and researchers are pursuing efforts to develop devices that convert the suns energy more efficiently.Photovoltaic EnergyPhotovoltaic cells (PV) are used worldwide to convert sunlight into electricity. The PV cell contains two layers of conductive material, one with a positive charge and the other with a controvert charge. When sunlight strikes the cell, some photons are absorbed by semiconductoratoms, outlet electrons that travel from the negative layer of the cell back to the positive layer, in the process creating a voltage. The flow of electrons through an external circuit produces electricity. Since undivided photovoltaic cells produce little power and voltage they generate only about one to two watts per cellthey are connected unneurotic electrically in series in a weatherproof module. To generate even more power and voltage, modules can be conne cted to one another to form a solar panel solar panels are grouped to form an array. The ability to add additional modules as needed is a significant advantage of PV systems.Solar Thermal EnergySolar thermal energy refers to technologies that use the suns energy to heat water and other heat reposition fluids for a variety of residential, industrial and utility applications. aboveboard and widelyused applications of solar thermal energy include solar water heating, swimming pool heating and agricultural drying. In the U.S., solar pool, water and space heating are currently the major applications of thermal energy. Flat-plate collectors large, insulated metal boxes with glass or plastic covers and dark heat riveting plates are the most common collectors used for home solar water and space heating. Other common varieties are evacuated-tube collectors and integral collector storage systems. All three types gather the suns energy, transform it to heat and then transfer that heat to water, a heat-transfer fluid or air. Flat plate collectors typically are mounted on the roof. Evacuated-tube collectors are sometimes used to heat water, but also have useful technical and Industrial applications where higher temperatures are required. The most powerful large-scale solar thermal technology, however, is concentrating solar power(CSP). While CSP can be PV-based, it generally refers to three solar thermal systemsparabolictroughs, solar dish/engines and power towers each of which is in use or under developmenttoday. These systems use mirrors or reflectors to focus sunlight to heat a fluid and make steam,which then is used to generate electricity. At present, only parabolic troughCSP systems arein commercial use in the U.S., with three installations in three states capable of generating 419 MW of electricity in all.45 Trough systems consist of a linear, parabolic-shaped reflector that focuses the suns energy on a receiver pipe, heating a transfer fluid rate of flow thr ough the pipe the transfer fluid then generates superheated steam which is ply to a turbine and electric generator to produce electricity. The troughs track the sun from einsteinium to West during the day so that the sun is continuously focused on the receiver pipes.3TransmissionSolar energy diff ers from most energy technologies in that it can be generated on site, reducing or eliminating fuel tape transport and electricity transmission and distribution costs. Solar water heating and space heating devices are complete systems that are not connected tothe electric grid. A PV system provides electric power directly to a user and can be used either asa stand-alone power source or connected to the electricity grid. Systems offering this flexibility sometimes are called distributed power generators. By contrast, utility-scale concentrating solar power plants use centralized power plants and transmission lines to distribute electricity to customers. In 2005, off -grid PV systems ac counted for about 18 percent of all PV installed worldwide.50 Homes in remote areas can use PV systems for lighting, home appliances and other electrical needs, saving the cost of extending power lines to a remote location. These systems require a storage device to store power generated during the day for nighttime use typically, this is a lead-acid battery bank. unlike gasoline-powered generators, PV systems do not require fuel deliveries and are clean and equable to operate.Net MeteringNet metering standards allow owners of qualifying solar energy systems to be compensated for the value of electric energy they produce they have been proven to promote solar energy systems. The IC2 Institute report that examined opportunities for the development of the Texas PV industry recommended the adoption of retail net metering in the state. Retail net metering attribute customers at the utilitys full retail rate for each kWh generated rather than at the utilitys avoided-cost rate, which is lower.COSTS AND BENEFITSBoth thermal and PV solar systems can produce electricity at significantly lower costs today thanIn the U.S., 2006 retail electricity prices for all sectors totald more than eight cents per kWh, and for residential electricity, the price averaged about 10 cents per kWh.76 By contrast, parabolic troughstyle CSP systems generated electricity at a cost of 12 cents per kWh in 2006, while PV systems generated electricity for about 18 to 23 cents per kWh.77 The retail price of electricity during peak hours, however, can rise to mingled with 25 and 40 cents per kWh in some parts of the U.S., making PV systems more competitive during peak periods.78 PV systems usually generate more electricity during the hottest time of the day, and thus can help to offset the need to add expensive electric generating capacity to satisfy peak demand in warm areas of the country. PV costs per kWh declined significantly over the last 16 years (from more than 45 cents per kWh in 1990 to about 23 cents per kWh in 2006), due primarily to manufacturing economies of scale as well as improved solar cell efficiency.79 The Solar Energy Industries Association (SEIA) notes that each doubling in accumulative manufacturing has brought prices down by about 18 percent.80 In the late(prenominal) five years alone, the world PV industry has grown by an average of 30 percent or more each year. In 2006, the U.S. PV industry expanded by 33 percent, compared to 19 percent for the world.81 The expansion of national income tax credits for commercial and residential solar energy projects, and state and utility incentives, particularly in California, fueled the U.S. industrys impressive festering in 2006. These federal tax credits, however, are set to expire at the end of 2008, and were not extended by Congress in 2007. A deficit of silicon and growing global demand for solar PV modules led to some cost increases in 2006 and 2007.82 About 90 percent of PV modules today exempt are made of crystalline silicon (polysilicon), which has been in short supply globally, constraining production and temporarily increasing the cost of solar cells.83 Polysilicon supplies are expected to remain tight and prices high until new plants under device are completed.84 Solarbuzz, an international solar energy consulting fi rm, predicts rapid growth in polysilicon capacity through 2011, and a resumption of faster rates of growth for the PV market.85 Unprecedented investment in manufacturing capacity is expected to result in lower PV costs over the long term. The cost of solar modules accounts for 50 to 60 percent of the total installed cost of a PV system, with other system parts, materials, assembly and installation accounting for the remainder.86 PV module costs have declined by about 80 percent over the last decade, but the installation costs have not dropped appreciably in recent years.87 installing costs vary depending on available sunlight, the typical energy utilizatio n of the home and the availability of experienced installers in the area. Unlike other energy sources, however, 90 percent of the cost of a PV system is incurred up front.88 once the system is installed, there are no fuel costs and the system requires little maintenance.