Solar electric power | Wikipedia audio article
Solar. Energy is radiant, light and heat from the Sun that is harnessed, using a range of ever-evolving, technologies. Such as solar heating, photovoltaics. Solar. Thermal energy solar, architecture. Molten, salt power plants, and artificial, photosynthesis. It is an important, source of renewable energy. And its technologies, are broadly characterized. As either passive, solar or active, solar depending, on how they capture, and distribute, solar energy, are converted, into solar power. Active. Solar techniques, include, the use of photovoltaic, systems. Concentrated. Solar power and, solar water heating to harness the energy. Passive. Solar techniques, include, orienting, a building to the Sun selecting. Materials, with favorable thermal, mass or light dispersing, properties, and designing, spaces that naturally, circulate, air, the. Large magnitude, of solar energy available. Makes it a highly appealing source, of electricity, the. United, Nations Development Program. In its 2000, world energy, assessment, found that the annual potential, of solar energy was. 1575. To 49,000. 837. Exajoules, eej, this. Is several times larger than the total world energy, consumption, which, was five hundred fifty nine point eight EJ, in 2012. In 2011. The International, Energy Agency, said, that the, development. Of affordable. Inexhaustible. And clean solar energy, technologies. Will have huge longer-term, benefits. It. Will increase, country's, energy security. Through reliance, on an indigenous. Inexhaustible. And mostly import, independent. Resource, enhanced. Sustainability. Reduce, pollution, lower, the costs, of mitigating, global, warming, and keep, fossil, fuel prices lower, than otherwise. These. Advantages. Are global, hence, the additional, costs, of the incentives, for early deployment should, be considered, learning investments. They must be wisely, spent and need to be widely shared. Topic. Potential. The, earth receives. 174. Peta watts PW. Of incoming, solar radiation. Insulation. 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 Earth's surface is mostly spread, across the visible and near-infrared ranges. With a small part in the near ultraviolet. Most. Of the world's population, live in areas with insulation, levels of 150. To 300 watts, per square meter or 3.5. 27.0. Kilowatt, hours per square meter per day solar, radiation. Is absorbed by, the Earth's land surface, oceans, which cover about 71%. Of the globe and atmosphere. Warm. Air containing, evaporated. Water from the oceans Rises causing, atmospheric, circulation. Or convection, when. The air reaches, a high altitude where. The temperature, is low water, vapor condenses into clouds which rain onto the Earth's surface, completing. The water cycle, the. Latent heat of water condensation, amplifies. Convection. Producing, atmospheric. Phenomena, such as wind cyclones. And anticyclones. Sunlight. Absorbed, by the oceans, and land masses keeps, the surface at an average temperature of 14, degrees Celsius, by. Photosynthesis. Green, plants convert solar energy into, chemical II stored energy which, produces, food wood, and the biomass, from which fossil, fuels are derived the total solar energy, absorbed, by Earth's atmosphere. Oceans, and land masses as approximately. 3 million, 850,000. Exajoules, eej, per year in. 2002. This was more energy, in one hour than the world used in one year. Photosynthesis. Captures, approximately. 3000. 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 we'll ever be obtained, from all of the Earth's non-renewable. Resources, of coal oil natural, gas, and, mined uranium combined. The. Potential, solar energy, that could be used by humans differs, from the amount of solar energy present. Near the surface of the planet because factors, such as G rafi time variation, cloud, cover and the land available to humans limit the amount of solar energy that we can acquire.
Geography. Affects solar energy, potential, because areas that are closer to the equator have a greater amount of solar radiation. However. The, use of photovoltaics, that, can follow the position, of the Sun can significantly increase. The solar energy potential. In areas that are farther from the equator time. Variation, affects the potential, of solar energy because during the night time there is little solar radiation. On the surface of the earth for solar panels to absorb, this. Limits, the amount of energy that solar panels, can absorb in one day, cloud. Cover can affect the potential of solar panels, because clouds, block incoming, light from the Sun and reduce the light available, for solar cells, in. Addition. Land, availability, has a large effect on the available, solar energy, because solar panels, can only be set up on land that is otherwise unused, and suitable, for solar panels, roofs. Have been found to be a suitable place for solar cells as many people have discovered that they can collect energy directly, from their homes this way other. Areas, that are suitable for solar cells are lands that are not being used for businesses, where solar plants, can be established solar, technologies. Are characterized, as either passive, or active depending. On the way they capture, convert, and distribute, sunlight, and enable solar energy, to be harnessed at different levels around the world mostly, depending, on distance from the equator, although. Solar energy, refers primarily to the use of solar radiation for. Practical, ends all renewable, energies, other than geothermal, power and tidal power derive, their energy either, directly, or indirectly from, the Sun. Active. Solar techniques, use photovoltaics. Concentrated. Solar power solar. Thermal collectors, pumps, and fans to convert sunlight into useful outputs. Passive. Solar techniques, include, selecting materials. With favorable thermal, properties, designing, spaces that naturally, circulate, air and referencing. The position, of a building to the Sun, active. Solar technologies. Increase the supply of energy and are considered, supply-side, technologies. While passive, solar technologies. Reduce the need for alternate, resources and, are generally considered demand-side.
Technologies. In 2000. The United Nations, Development Program. UN, Department of Economic, and Social Affairs, and, world Energy, Council published, an estimate, of the potential solar, energy, that could be used by humans each year that took into account factors such, as insulation, cloud, cover and the land that is usable by humans, the. Estimate, found that solar energy has a global, potential of one thousand, five hundred seventy. Five to forty nine thousand. 837, each a per year see table below. Topic. Thermal. Energy. Solar. Thermal technologies. Can be used for water heating space, heating space, cooling and process, heat generation. Topic. Early. Commercial, adaptation. In, 1878. At the Universal, Exposition in, Paris, Augustine, mucho successfully. Demonstrated, a solar steam engine but couldn't continue development, because, of cheap coal and other factors, in. 1897. Frank, Schumann, a u.s. inventor, engineer, and solar energy pioneer. Built a small demonstration solar. Engine, that worked by reflecting, solar energy, onto square boxes, filled with ether which has a lower boiling point than water and were fitted internally, with black pipes which in turn powered, a steam engine in. 1908. Schumann, formed the Sun power company, with the intent of building larger, solar power plants. He. Along, with his technical, adviser ASC, Ackerman. And British physicist, Sir Charles Vernon Boyce developed. An improved system using, mirrors to reflect solar, energy, upon collector, boxes, increasing. Heating capacity to the extent, that water could now be used instead of ether, Schumann. Then constructed, a full-scale steam engine powered by low-pressure water enabling. Him to patent the entire solar engine, system by 1912. Schumann. Built the world's first solar, thermal power station, in Maadi Egypt, between 1912. And 1913. His. Plant used parabolic, troughs to power a 45, to 52 kilowatts, 60. To 70 horsepower engine. That pumped more than 22,000. Litres, 4,800. MPL. 5,800. U.s. gal of water per, minute from the nile river to adjacent cotton, fields, although. The outbreak, of World War one and the discovery, of cheap oil in the 1930s. Discouraged, the advancement, of solar energy Schumann's, vision and basic design were resurrected in the 1970s. With a new wave of interest in solar thermal energy in. 1916. Schumann, was quoted, in the media advocating. Solar energies, utilization. Saying. We. Have proved the commercial, profit of Sun power in the tropics, and have more particularly, proved, that after our stores of oil and coal are exhausted, the human race can receive, unlimited power, from the Rays of the Sun. Topic. Water, heating. Solar. Hot water systems. Use sunlight to heat water in, low geographical. Latitudes, below 40 degrees from, 60, to 70 percent of the domestic hot water use, with temperatures, up to 60, degrees Celsius can, be provided by solar heating, systems, the. Most common, types of solar water heaters, are evacuated, tube collectors. 44%. And glazed flat plate collectors. 34%. Generally, used for domestic hot water and, unglazed, plastic, collectors. 21%. Used mainly to heat swimming, pools as of 2007. The, total installed capacity of, solar hot water systems. Was approximately. 150. For thermal gigawatt, GW. Th. China. As the world leader in their deployment, with 70, GW, T H installed, as of 2006. And a long-term goal of 210. GW, T H by 2020. Israel. And Cyprus are the per capita leaders in the use of solar hot water systems.
With Over 90%, of homes using them in the. United, States Canada, and Australia heating. Swimming pools as the dominant application. Of solar hot water with, an installed capacity of, 18, GW, th as of 2005. Topic. Heating. Cooling, and ventilation. In, the United States heating, ventilation, and air conditioning hvac. Systems. Account for 30 percent 4.65. Ej per year of the energy, used in commercial, buildings and nearly 50 percent 10.1. Ej per year of the energy, used in residential, buildings, solar. Heating, cooling and ventilation technologies. Can be used to offset a portion, of this energy. Thermal. Masses, any material, that can be used to store heat heat. From the Sun in the case of solar energy. Common. Thermal mass materials. Include, stone cement, and water, historically. They have been used in arid climates, or warm temperate, regions to keep buildings, cool by absorbing, solar energy, during the day and radiating, stored heat to the cooler atmosphere, at night however. They, can be used in cold temperate, areas to maintain warmth as well the. Size and placement of thermal mass depend, on several factors such as climate day, lighting and shading conditions. When. Properly, incorporated. Thermal mass maintains, space temperatures. In a comfortable, range and reduces, the need for auxiliary, heating and cooling equipment a solar chimney or thermal, chimney in this context. Is a passive, solar ventilation. System composed of a vertical shaft connecting, the interior, and exterior of, a building as the. Chimney warms the air inside, is heated causing, an updraft that pulls air through the building. Performance. Can be improved by using glazing. And thermal mass materials. In a way that mimics greenhouses. Deciduous. Trees and plants have been promoted, as a means of controlling, solar, heating, and cooling when. Planted, on the southern side of a building in the northern hemisphere or, the northern site in the southern hemisphere their, leaves provide shade, during the summer while the bare limbs allow light to pass during, the winter, since. Bear leafless, trees shade one-third to one-half of, incident, solar radiation there. Is a balance, between the benefits of summer shading, and the corresponding. Loss of winter heating in, climates. With significant. Heating loads deciduous. Trees should not be planted, on the equator facing, side of a building because they will interfere, with winter, solar availability. They can however be used on the east and west sights to provide a degree of summer shading, without appreciably, affecting, winter solar gain. Topic. Cooking. Solar, cookers, use sunlight, for cooking drying, and pasteurization. They, can be grouped into three broad categories box. Cookers, panel, cookers and reflector, cookers, the. Simplest, solar cooker, as the Box cooker, first built by Horace de Sousa in, 1767. A basic. Box cooker, consists, of an insulated, container with a transparent, lid it, can, be used effectively with, partially, overcast, skies and will typically, reach temperatures, of 90 to 150. Degrees, Celsius. 194. To 302. Degrees Fahrenheit. Panel. Cookers, use a reflective, panel to direct sunlight onto an insulated, container and, reach temperatures, comparable, to box cookers. Reflector. Cookers, use various, concentrating. Geometries, dish trough, Fran, L mirrors to focus light on a cooking, container, these. Cookers, reach temperatures. Of 315. Degrees Celsius. 599. Degrees Fahrenheit, and above but require direct light to function, properly and must be repositioned, to track the Sun. Topic. Process. Heat. Solar. Concentrating. Technologies, such as parabolic, dish trough, and Schaeffler reflectors, can provide process, heat for commercial, and industrial applications. The. First commercial, system was the solar total, energy project, step, in Shenandoah Georgia. U.s. where a field of 114. Parabolic, dishes provided. 50%. Of the process, heating air conditioning and. Electrical, requirements for, a clothing factory, this. Grid-connected cogeneration. System. Provided, 400, kilowatts, of electricity plus.
Thermal Energy, in the form of 401, kilowatts, team and 468. Kilowatts, chilled water and had a one-hour peak load thermal, storage. Evaporation. Ponds are shallow pools that concentrate, dissolved, solids, through evaporation, the. Use of evaporation, ponds, to obtain salt from seawater as one of the oldest applications. Of solar energy. Modern. Uses include concentrating. Brine solutions, used in leach mining, and removing dissolved, solids, from waste streams. Clothes. Lines clothes, horses, and clothes racks dry clothes through evaporation, by wind and sunlight without consuming, electricity or, gas in, some. States of the United, States legislation protects. The right, to dry clothes. Unglazed. Transpired. Collectors, UTC. Are perforated, sun-facing, walls used for pre heating ventilation, air. UTC's. Can raise the incoming air temperature, up to 22, degrees Celsius 40, degrees Fahrenheit and deliver outlet temperatures, of 45, to 60, degrees Celsius, 113. To 140. Degrees Fahrenheit, the. Short payback period, of transpired, collectors, 3 to 12 years makes them a more cost-effective, alternative. Than glazed collection, systems, as of. 2003. Over 80 systems, with a combined, collector, area of 35,000. Square metres 380. Thousand, square feet had been installed worldwide including. An 860. Square metres, nine thousand, three hundred square feet collector, in Costa Rica used for drying coffee beans in a 1300, square metres 14,000. Square feet collector, in Coimbatore, India, used, for drying marigold. Topic. Water, treatment. Solar, distillation can, be used to make saline, or brackish water potable, the. First recorded, instance of this was by sixteenth century, Arab alchemists. A, large-scale. Solar distillation project. Was first constructed in 1872. In, the chilean mining town, of las salinas, the. Plant which had solar collection, area of, 4,700. Square meters. 51,000, square feet could produce up to 22,000. 700. L5000. MPL 6000, u.s. gal per day and operate, for 40 years. Individual. Still designs include, single slope double, slope or greenhouse type, vertical. Conical, inverted, absorber, multi, wick and multiple, effect, these. Stills can operate in passive, active, or hybrid, modes, double. Slope stills are the most economical, for decentralized domestic. Purposes, while active, multiple, effect units are more suitable for large-scale applications. Solar, water disinfection saudis, involves. Exposing water filled, plastic polyethylene. Terephthalate pet. Bottles. To sunlight for several, hours. Exposure. Times, vary depending on, weather and climate from, a minimum of six hours to two days during fully overcast, conditions, it.
Is Recommended. By the World Health Organization. As a viable method for household, water treatment, and safe storage. Over. Two million people in developing countries use this method for their daily drinking, water solar, energy, may be used in a wider stabilization. Pond to treat wastewater, without, chemicals, or electricity, a further. Environmental advantage. Is that algae, grow in such ponds and consume carbon, dioxide, in photosynthesis. Although algae may produce toxic, chemicals, that make the water unusable. Topic. Molten. Salt technology. Molten-salt. Can, be employed as a thermal energy storage method. To retain thermal energy collected, by a solar tower or solar trough of a concentrated. Solar power plant so that it can be used to generate electricity, in bad weather or at night it. Was, demonstrated in the solar ii project from 1995. To 1999. The. System, is predicted, to have an annual efficiency. Of 99, percent a reference, to the energy, retained by storing, heat before turning, it into electricity, versus, converting, heat directly, into electricity. The. Molten salt mixture, is very the. Most extended, mixture, contains, sodium nitrate, potassium nitrate. And calcium, nitrate, it. Is non-flammable, and, non-toxic and. Has already been used in the chemical and metals industries, as a heat transport, fluid, so experience, with such systems, exists, in non solar applications. The. Salt melts at 131. Degrees Celsius. 268. Degrees, Fahrenheit, it, is, kept liquid at 288. Degrees Celsius. 550. Degrees Fahrenheit, in an insulated, cold. Storage. Tank the, liquid salt is pumped through panels, in a solar collector where, the focused Sun heats it to 566. Degrees Celsius, 1000, 51, degrees Fahrenheit. It, is, then sent to a hot storage, tank this, is so well insulated that, the thermal energy can be usefully, stored for up to a week when, electricity, is needed the hot salt is pumped to a conventional, steam generator, to produce superheated. Steam for a turbine, generator, as used in any conventional coal, oil or, nuclear, power plant, a, 100. Megawatt turbine, would need a tank about 9.1, meters 30 feet tall and 24, meters 79. Feet in diameter to, drive it for four hours by this design. Several. Parabolic. Trough power plants, in Spain and solar power tower developer, Solaris erv used this thermal energy storage concept. The. Solana, Generating Station. In the US has six hours of storage by molten salt the. Maria Elena plant, as a 400, megawatts, thermosolar. Complex, in the northern Chilean region of Antofagasta, employ molten, salt technology. Topic. Electricity. Production. Solar. Power is the conversion of sunlight into electricity either. Directly, using photovoltaics. PV. Or indirectly. Using concentrated. Solar power, CSP. CSP. Systems, use lenses or, mirrors and, tracking systems to focus a large area of sunlight into, a small beam. PV. Converts, light into electric. Current using the photoelectric. Effect. Solar. Power is anticipated. To become the world's largest source, of electricity, by 2050, with solar photovoltaics, and, concentrated. Solar power contributing. 16, and 11%, to the global overall consumption, respectively. In. 2016. After another, year of rapid growth solar, generated. 1.3. Percent of global power commercial. Concentrated. Solar power plants, were first developed, in the 1980s. The. 392. Megawatts, Ivanpah, solar power, facility. In the Mojave Desert of California. Is the largest solar power plant, in the world other. Large, concentrated. Solar power plants, include the 150. Megawatt Sol Nova solar power station, in the 100, megawatts and a Seoul solar power station, both in Spain the. 250. Megawatts, agua caliente solar project, in the United States and the 221. Megawatts, Charaka, solar park in India are the world's largest photovoltaic, plants. Solar. Projects. Exceeding, one gigawatt, are being developed but most of the deployed photovoltaics, are, in small rooftop, arrays of less than five kilowatts, which are connected, to the grid using net metering and/or a feed-in tariff. Topic. Photovoltaics. In, the last two decades photovoltaics. PV. Also, known as solar PV, has evolved, from a pure niche market, of small scale applications. Towards, becoming a mainstream electricity. Source a solar. Cell is a device that converts light directly, into electricity using, the photoelectric. Effect the. First solar cell was constructed, by Charles, Fritts in the 1880s. In. 1931. A German engineer dr., Bruno Lange developed. A photocell, using, silver selenite, in place of copper oxide, although. The prototype, selenium, cells converted, less than 1%, of incident, light into electricity. Both Ernst Werner von Siemens and James Clerk Maxwell recognized. The importance, of this discovery. Following. The work of Russell Lowell in the 1940s. Researchers Gerald. Pearson Calvin. Fuller and Daryl Chapin created. The crystalline, silicon, solar cell in 1954.
These. Early solar cells cost, 286. United, States dollars, per watt and reached efficiencies. Of four point five to six percent, by. 2012. Available, efficiencies, exceeded, 20%, and the maximum efficiency of research photovoltaics, was, in excess of 40%. Topic. Concentrated. Solar power. Concentrating. Solar power, CSP. Systems. Use lenses or, mirrors and, tracking systems to focus a large area of sunlight into. A small beam the. Concentrated. Heat is then used as a heat source for a conventional, power plant, a wide. Range of concentrating. Technologies. Exists, the most developed, are the parabolic, trough the concentrating. Linear Fornell reflector, the Stirling dish in the solar power tower. Various. Techniques are used to track the Sun and focus light in all, of these systems a working fluid is heated by the concentrated. Sunlight and is then used for power generation or. Energy storage. Topic. Architecture. And urban planning. Sunlight. Has influenced, building designs since the beginning of architectural. History, advanced. Solar architecture. And urban planning methods were first employed by the Greeks in Chinese who, oriented, their buildings toward the south to provide light and warmth the common features of passive, solar architecture. Are orientation. Relative to the Sun compact. Proportion, a low surface area, to volume ratio, selective. Shading, overhangs, and thermal, mass, when. These features, are tailored to the local climate and environment, they can produce well lit spaces, that stay in a comfortable, temperature, range. Socrates. Megaron house as a classic, example of, passive solar design the. Most recent, approaches, to solar design use computer, modeling tying together solar, lighting heating and ventilation, systems in, an integrated, solar, design package. Active. Solar equipments such as pumps fans and switchable, windows can complement, passive, design and improve system, performance. Urban. Heat islands, UHI, are metropolitan. Areas with higher temperatures, than that of the surrounding, environment the. Higher temperatures. Result, from increased absorption, of solar energy by urban materials, such as asphalt, and concrete which. Have lower albedo, and higher heat capacities, than those in the natural, environment a straightforward. Method, of counteracting. The UHI effect as to paint buildings, and roads white and to plant trees in the area, using. These methods a hypothetical, cool. Communities. Program. In Los Angeles has, projected, that urban temperatures, could be reduced by approximately 3. Degrees Celsius at an estimated, cost of 1 billion United, States dollars, giving, estimated, total annual benefits, of 530. Million United, States dollars, from reduced air conditioning, costs and healthcare savings. Topic. Agriculture. And horticulture. Agriculture. And horticulture seek. To optimize the capture of solar energy in order to optimize the productivity. Of plants. Techniques. Such as timed planting, cycles, tailored, row orientation. Staggered, heights between rows and the mixing of plant varieties can, improve crop yields, while. Sunlight, is generally, considered a plentiful resource, the exceptions, highlight the importance, of solar energy to agriculture. During. The short growing seasons, of the Little Ice Age french, and english farmers, employed fruit walls to maximize, the collection, of solar energy, these. Walls acted, as thermal masses, and accelerated. Ripening, by keeping plants warm early. Fruit, walls were built perpendicular. To the ground and facing, south but over time sloping. Walls were developed, to make better use of sunlight, in. 1699. Nicolas. Patio de Dhulia even, suggested, using a tracking mechanism which could pivot to follow the Sun. Applications. Of solar energy and, agriculture. Aside from growing crops include, pumping water drying, crops brooding, chicks and drying chicken, manure more. Recently, the technology, has been embraced, by vintners, who use the energy, generated, by solar panels, to power great presses, greenhouses, converts, solar light to heat enabling. Year-round production. And the growth in enclosed, environments. Of specialty, crops and other plants, not naturally, suited to the local climate. Primitive. Greenhouses, were, first used during Roman times to, produce cucumbers, year-round for, the Roman emperor Tiberius. The. First modern greenhouses, were built in Europe in the 16th, century to keep exotic, plants brought back from explorations. Abroad. Greenhouses. Remain, an important, part of horticulture, today and plastic, transparent, materials, have also been used to similar effect in polytunnel Zandro covers.
Topic. Transport. Development. Of a solar-powered car, has been an engineering, goal since the 1980s. The. World Solar Challenge as, a biannual, solar-powered. Car race where teams from universities. And enterprises. Compete, over 3021, kilometres. 1877. Miles across, Central, Australia from, Darwin to Adelaide in. 1987. When it was founded, the winners average, speed was 67. Km/h. 42. Miles per hour and by 2007. The winners average, speed had improved to 90 point 8 7 km/h. 56. Point 4 6 miles per hour, the. North American Solar, Challenge and the planned South African, Solar Challenge are comparable, competitions. That reflect an international, interest, in the engineering, and development, of solar powered, vehicles, some vehicles use solar panels for auxiliary, power such, as for air conditioning, to keep the interior cool, thus reducing, fuel consumption, in, 1975. The first practical, solar boat was constructed, in England by. 1995. Passenger. Boats incorporating. PV panels, began appearing and are now used extensively, in. 1996. Konnichi Horry made the first solar-powered, crossing. Of the Pacific, Ocean and the Sun 21, catamaran, made the first solar-powered, crossing. Of the Atlantic Ocean, in the winter of 2006. 2007. There. Were plans to circumnavigate, the globe in 2010, in 1974. The unmanned Astro flight sunrise airplane, made the first solar flight on the, 29th. Of April 1979. The solar riser made the first flight in a solar-powered fully, controlled, man carrying, flying machine, reaching, an altitude of 40 feet 12, meters in. 1980. The gossamer penguin, made the first piloted, flights powered, solely by photovoltaics. This. Was quickly followed by the Solar challenger, which crossed the English Channel in, July 1981. In. 1990. Eric Scott Raymond in 21, hops flew from California, to North Carolina, using, solar power. Developments. Then turned back to unmanned aerial, vehicles, you, with, the Pathfinder. 1997. And subsequent. Designs culminating. In the Helios which set the altitude record, for a non rocket-propelled aircraft.
At Twenty nine thousand, five hundred twenty four meters ninety, six thousand, eight hundred sixty, four feet in 2001. The. Zephyr developed, by BAE Systems is, the latest in a line of record-breaking, solar aircraft, making, a fifty four hour flight in, 2007. And month-long flights, were envisioned by 2010, as of. 2016. Solar Impulse an electric, aircraft is currently, circumnavigating. The globe it, is, a single-seat. Plane powered by solar cells and capable, of taking off under its own power the, design. Allows the aircraft to, remain airborne for several days a solar balloon, as a black balloon that is filled with ordinary air as, sunlight. Shines on the balloon the air inside, is heated and expands, causing an upward buoyancy, force much like an artificially, heated hot-air balloon, some. Solar balloons, are large enough for human, flight but usage is generally, limited to the toy market as the surface area to payload weight ratio, is relatively, high. Topic. Fuel, production. Solar, chemical, processes, use solar energy to, drive chemical, reactions, these. Processes. Offset, energy, that would otherwise come, from a fossil fuel source and can also convert, solar energy in, disturbance. Portable, fuels, Solar, induced, chemical, reactions, can be divided into thermo chemical or photochemical. A variety. Of fuels, can be produced by artificial. Photosynthesis. The, multi electron, catalytic, chemistry, involved, in making carbon-based, fuels such, as methanol, from reduction, of carbon dioxide as. Challenging, a feasible, alternative as, hydrogen, production from protons, though use of water as the source of electrons, as plants, do requires, mastering. The multi electron, oxidation of, two water molecules, two molecular oxygen. Some. Have envisaged working, solar fuel plants, in coastal, metropolitan. Areas by 2050. The splitting of seawater providing, hydrogen, to be run through adjacent. Fuel cell electric power plants, and the pure water by-product, going directly into the municipal, water system. Another. Vision involves, all human structures, covering, the Earth's surface, ie roads, vehicles, and buildings doing, photosynthesis. More efficiently, than plants, hydrogen. Production technologies. Have been a significant. Area of solar chemical, research since the 1970s. Aside. From electrolysis. Driven, by photovoltaic or, photochemical. Cells several, thermo chemical processes. Have also been explored. One. Such route uses concentrators. To split water into oxygen and hydrogen at, high temperatures. 2,300. To, 2,600. Degrees Celsius. Or, 4,200. To, 4700. Degrees Fahrenheit. Another. Approach uses, the heat from solar concentrators. To drive the steam reformation, of natural, gas thereby increasing, the overall hydrogen. Yield compared, to conventional, reforming, methods, thermo. Chemical cycles, characterized. By the decomposition. And regeneration, of reactants, present another Avenue for hydrogen production, the. Sol zinc process, under development, at the Weizmann, Institute of, Science uses. A 1 megawatt solar furnace, to decompose, zinc oxide, Zn, o at temperatures, above, 1,200. Degrees Celsius. Thousand, two hundred degrees, Fahrenheit, this. Initial, reaction, produces, pure zinc which, can subsequently, be reacted, with water to, produce hydrogen. Topic. Energy. Storage, methods. You. Thermal. Mass systems, can store solar energy, in the form of heat at domestically, useful temperatures, for daily or inter seasonal, durations. Thermal. Storage systems, generally, use readily, available materials. With high specific, heat capacities, such as water earth and stone. Well-designed. Systems, can lower peak demand shift time of use to off-peak hours and, reduce overall heating, and cooling requirements.
Phase Change, materials, such as paraffin, wax and bluebird salt are another thermal, storage medium, these. Materials, are inexpensive, readily, available and, can deliver domestically. Useful temperatures, approximately. 64, degrees Celsius, or, 147. Degrees Fahrenheit. The. Dover. House in Dover. Massachusetts, was. The first to use a globe or salt heating system, in 1948. Solar. Energy, can also be stored at high temperatures. Using molten salts. Salts. Are an effective storage medium, because they are low cost have, a high specific heat capacity. And can deliver heat at temperatures, compatible, with conventional, power systems. The. Solar ii project used this method of energy storage allowing, it to store, 1.44. Terajoules. 400,000, kilowatt, hours in its sixty-eight cubic, meters storage, tank with an annual storage, efficiency of about 99%. Off-grid. PV systems. Have traditionally, used rechargeable. Batteries, to store excess electricity, with. Grid-tied, systems, excess, electricity, can be sent to the transmission, grid while standard, grid electricity, can be used to meet shortfalls. Net. Metering programs, give household, systems a credit for any electricity, they deliver to the grid this. Is handled by rolling, back the meter whenever, the home produces, more electricity than it consumes if the. Net electricity. Use is below zero the utility, then rolls over the kilowatt, hour credit to the next month other. Approaches. Involve the use of two meters to measure electricity. Consumed, versus electricity. Produced, this. Is less common due to the increased, installation. Cost of the second meter most. Standard, meters accurately, measure in both directions, making, a second meter unnecessary. Pumped-storage. Hydroelectricity. Stores, energy in the form of water pumped when energy is available from, a lower elevation reservoir. To a higher elevation one, the. Energy, is recovered when demand is high by releasing the water with the pump becoming a hydroelectric. Power generator. Topic. Development. Deployment. And economics. Beginning. With the surge in coal use which accompanied, the Industrial, Revolution energy. Consumption, has steadily transitioned. From wood and biomass, to fossil, fuels the. Early development, of solar technologies. Starting in the 1860s. Was driven by an expectation, that, coal would soon become scarce. However. Development, of, solar technologies. Stagnated. In the early 20th, century in, the face of the increasing, availability, economy. And utility. Of coal and petroleum the. 1973. Oil embargo, and, 1979. Energy crisis. Caused a reorganization. Of energy policies, around the world and brought renewed attention to developing solar technologies. Deployment. Strategies, focused, on incentive, programs, such as a federal, photovoltaic, utilization. Program in the US and the sunshine program, in Japan other. Efforts, included, the formation of research facilities, in the US, Cerie now NREL. Japan, and II do and Germany, Freneau fir Institute, for solar energy systems. Ice commercial. Solar water heaters, began appearing in the United, States in the 1890s. These. Systems saw increasing, use until the 1920s. But were gradually, replaced by cheaper and more reliable heating. Fuels as with. Photovoltaics, solar. Water heating attracted, renewed attention, as a result, of the oil crises. In the 1970s. But interest subsided, in the 1980s. Due to falling petroleum, prices.
Development. In the solar water heating sector progressed, steadily throughout, the 1990s, and, annual growth rates have averaged 20%, since 1999. Although. Generally. Underestimated. Solar, water heating and cooling is by far the most widely deployed, solar, technology. With an estimated, capacity of, 154. Gigawatts, as of 2007. The International Energy Agency has said that solar energy can make considerable, contributions. To solving, some of the most urgent problems, the world now faces. The. Development, of affordable, inexhaustible. And clean solar energy, technologies. Will have huge longer-term, benefits, it. Will increase country's, energy security. Through reliance, on an indigenous. Inexhaustible. And mostly, import independent, resource, enhance, sustainability. Reduce, pollution lower, the costs of mitigating climate change and keep fossil. Fuel prices lower than otherwise, these. Advantages. Are global, hence, the additional, costs, of the incentives, for early deployment should, be considered, learning investments. They must be wisely spent and need to be widely shared in. 2011. A report by the International, Energy Agency found. That solar energy technologies. Such as photovoltaics, solar. Hot water and, concentrated. Solar power could provide a third of the world's energy by 2060. If politicians, commit, to limiting climate, change the. Energy from the Sun could play a key role in decarbonizing. The global economy, alongside improvements. In energy efficiency, and imposing, costs on greenhouse gas emitters, the, strength of solar is the incredible, variety and, flexibility. Of applications. From small scale to big scale. We, have proved that. After. Our stores of oil and coal are exhausted, the human race can receive, unlimited power, from the Rays of the Sun. Topic. ISO, standards. The, International. Organization for, Standardization, has, established several, standards, relating, to solar energy equipment. For. Example ISO. 9000. 50 relates to glass in building while ISO 10000, 217. Relates to the materials, used in solar water heaters. Equals. Equals, see also.
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