Solar energy is the shining and hot light of the Sun that is exploited using evolving technologies such as solar heating, photovoltaic, solar thermal energy, solar architecture, liquid salt generation and artificial photosynthesis.
It is an important source of renewable energy and its technology is widely characterized as a passive sun or active sun depending on how they capture and distribute solar energy or convert it into solar power. Active solar techniques include the use of photovoltaic systems, concentrated solar power and solar water heaters to harness energy. Passive solar techniques include orientating a building to the Sun, selecting material with a favorable thermal mass or light-absorbing property, and designing a space naturally circulating the air.
The amount of solar energy available makes it a very attractive power source. The United Nations Development Program in the 2000 World Energy Review found that the annual potential of solar energy is 1,575-49,837 exajoules (EJ). This is several times greater than the total world energy consumption, which is 559.8 EJ in 2012.
In 2011, the International Energy Agency said that "the development of affordable, endless and clean solar energy technologies will have enormous long-term benefits that will enhance the energy security of nations through dependence on indigenous resources, depleting and largely import-independent, increasing sustainability, reducing pollution, lowering the costs of mitigating global warming, and keeping fossil fuel prices lower than others. These gains are global, so incentive costs for initial deployment should be regarded as a learning investment, they should be wisely spent and should be shared widely ".
Video Solar energy
Potential
The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) in the upper atmosphere. About 30% is reflected back into space while the rest is absorbed by clouds, oceans and land. The spectrum of sunlight on the earth's surface is largely dispersed in the visible and near-infrared range with small parts near the ultraviolet. Most of the world's population lives in areas with insulation levels of 150-300 watts/mÃ, or 3.5-7.0 kWh/mÃ,² per day.
Sun radiation is absorbed by the Earth's surface, the oceans - covering about 71% of the world - and the atmosphere. The warm air containing water that evaporates from the ocean rises, causing atmospheric circulation or convection. When the air reaches a high altitude, where temperatures are low, water vapor condenses into clouds, which rain to the Earth's surface, completing the water cycle. The latent heat of water condensation strengthens the convection, producing atmospheric phenomena such as wind, cyclone and anti-cyclone. Sunlight absorbed by oceans and landmasses keeps surfaces at an average temperature of 14 Â ° C. With photosynthesis, green plants convert solar energy into chemically stored energy, which produces food, wood and biomass from which fossil fuels originate.
The total solar energy absorbed by Earth, ocean, and land atmosphere is about 3,850,000 eksajoules (EJ) per year. In 2002, this was more energy in an hour than the world used in a year. Photosynthesis captures about 3,000 EJs per year in biomass. The amount of solar energy that reaches the surface of the planet is so large that in a year, that's roughly double that of all coal resources, oil, natural gas, and non-renewable uranium mines combined. ,
The potential solar energy that humans can use is different from the amount of solar energy that is near the planet's surface because factors such as geography, time variation, cloud cover, and available land for humans limit the amount of solar energy we can obtain.
Geography affects the potential of solar energy because the area closer to the equator has a greater amount of solar radiation. However, the use of photovoltaics that can follow the sun's position can significantly increase the solar energy potential in areas further away from the equator. Variations of time affect the potential of solar energy because at night there is little solar radiation on the Earth's surface to be absorbed by solar panels. This limits the amount of energy that can be absorbed by solar panels in a single day. Cloud cover can affect the potential of solar panels because clouds block the incoming light from the sun and reduce the light available to solar cells.
In addition, the availability of land has a major effect on solar energy available because solar panels can only be installed on land declared unused and suitable for solar panels. The roof has been found to be a suitable place for solar cells, as many people have found that they can collect energy directly from their homes this way. Another area suitable for solar cells is land that is not used for businesses where solar plants can be established.
Solar technology is characterized as passive or active depending on how they capture, transform and distribute sunlight and allow solar energy to be utilized at various levels around the world, largely depending on the distance from the equator. Although solar energy mainly refers to the use of solar radiation for practical purposes, all renewable energies, in addition to geothermal and tidal power, derive their energy either directly or indirectly from the Sun.
Active solar techniques use photovoltaic, concentrated solar power, solar thermal collectors, pumps, and fans to convert sunlight into useful output. Passive solar techniques include selecting materials with favorable thermal properties, designing a space that naturally circulates air, and position reference buildings to the Sun. Active solar technology increases energy supply and is perceived as supply-side technology, while passive solar technology reduces the need for alternative resources and is generally regarded as demand-side technology.
In 2000, the United Nations Development Program, the United Nations Department of Economic and Social Affairs, and the World Energy Council published an estimate of the potential for solar energy that humans can use every year that takes into account factors such as insolation, cloud cover and usable soil by humans. Estimates found that solar energy has a global potential of 1,575-49,837 EJs per year (see table below) .
Maps Solar energy
Thermal energy
Solar thermal technology can be used for water heating, space heating, cooling chamber and heat forming process.
Initial commercial adaptation
In 1878, at the Universal Exposition in Paris, Augustin Mouchot managed to show the solar steam engine, but was unable to continue development due to cheap coal and other factors.
In 1897, Frank Shuman, an American inventor, engineer and pioneer of solar energy, built a small demonstration solar machine that works by reflecting solar energy into a square box filled with ether, which has a lower boiling point than water, internal with black pipe which in turn powered the steam engine. In 1908 Shuman established the Solar Power Company with the aim of building a larger solar power plant. He, along with his technical adviser, U.S.E. Ackermann and the English physicist Sir Charles Vernon Boys, developed an enhanced system using mirrors to reflect solar energy in a collector box, increasing heating capacity as far as water can now be used instead of ether. Shuman then built a full-scale steam engine powered by low-pressure water, allowing it to patent the entire solar engine system in 1912.
Shuman built the world's first solar thermal power plant in Maadi, Egypt, between 1912 and 1913. The plant uses a parabolic trough to power a 45-52 kilowatt (60-70 hp) engine that pumps more than 22,000 liters (4,800 laborers, 5,800 US gal) of water per minute from the Nile to adjacent cotton fields. Despite the outbreak of World War I and the discovery of cheap oils in the 1930s hampered the progress of solar energy, Shuman's basic vision and design was raised in the 1970s with a new wave of interest in solar thermal energy. In 1916, Shuman was quoted in the media advocating the utilization of solar energy, saying:
We have proved the commercial advantages of solar power in the tropics and more specifically to prove that once our stores of oil and coal run out, mankind can receive unlimited power from the sun.
Water heating
The solar hot water system uses sunlight to heat the water. In low geographic latitudes (below 40 degrees) of 60 to 70% of domestic hot water usage with temperatures up to 60 ° C may be provided by solar heating systems. The most common types of solar water heaters are evacuated tube collectors (44%) and glossy flat plate collectors (34%) commonly used for domestic hot water; and glaze plastic collectors (21%) are used primarily for heating swimming pools.
In 2007, the total installed capacity of the solar thermal system was about 154 gigawatts of thermal (GW th ). China is the world leader in its distribution with 70 GW th installed in 2006 and the long-term goal of 210 GW th in 2020. Israel and Cyprus are per capita leaders in the use of hot water systems sun with over 90% of homes that use it. In the United States, Canada and Australia, heating swimming pools is the dominant application of solar hot water with an installed capacity of 18 GW th in 2005.
Heating, cooling and ventilation
In the United States, heating, ventilation and air conditioning systems (HVAC) account for 30% (4.65 EJ/yr) of energy used in commercial buildings and nearly 50% (10.1 EJ/yr) of energy used in residential buildings. Solar heating, cooling and ventilation technology can be used to offset some of this energy.
Thermal mass is a material that can be used to store 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 dry climates or warm climates to keep buildings cool by absorbing the sun's energy during the day and emitting stored heat into the cooler atmosphere at night. However, they can be used in cold climates to maintain warmth as well. The size and placement of thermal mass depends on several factors such as climate, sunlight and shadow conditions. When properly inserted, thermal mass maintains room temperature within a comfortable range and reduces the need for additional heating and cooling equipment.
The solar chimney (or thermal chimney, in this context) is a passive solar vent system consisting of a vertical axis connecting the inside and outside of the building. As the chimney warms up, the air inside is heated and causes an upward flow of air that pushes air through the building. Performance can be improved by using glass and thermal mass materials in a way that mimics a greenhouse.
Fallen trees and plants have been promoted as a means of controlling solar heating and cooling. When planted on the southern side of buildings in the northern hemisphere or the northern side of the southern hemisphere, their leaves provide shade during the summer, while the bare limbs allow light to pass through during the winter. Since bare and leafless trees overshadow 1/3 to 1/2 of the solar radiation that occurs, there is a balance between the benefits of summer shade and the loss of winter heating. In a climate with significant heating loads, deciduous trees should not be planted on the side facing the Equator of a building as they would interfere with the availability of the winter sun. They can, however, be used on the east and west sides to provide summer shade levels without sufficiently affecting the winter sun's gain.
Cooking
The solar stove uses sunlight for cooking, drying and pasteurization. They can be grouped into three broad categories: rice cooker box, stove panel and reflector stove. The simplest solar cooker is a box cooker first made by Horace de Saussure in 1767. The base box consists of an insulated container with a transparent cap. It can be used effectively with partially overcast skies and will usually reach temperatures of 90-150 ° C (194-302 ° F). The panel cooker uses a reflective panel to direct sunlight to an isolated container and reach a temperature proportional to the cooker's box. The reflector stove uses a variety of concentrating geometries (plates, troughs, Fresnel mirrors) to focus light on the cooking container. This cooker reaches 315 ° C (599 ° F) and above but requires direct light to function properly and must be repositioned to track the Sun.
Heat process
Solar concentrating technologies such as parabolic dishes, troughs and reflectors Scheffler can provide process heat for commercial and industrial applications. The first commercial system is the Total Solar Energy Project (STEP) in Shenandoah, Georgia, USA, where a field with 114 parabolic dishes provides 50% of heating, air conditioning and power requirements for the clothing factory. This grid-connected cogeneration system provides 400 kW of electricity plus heat energy in the form of steam of 401 kW and 468 kW of cold water, and has a one hour load peak load loading. The evaporation pool is a shallow pond that concentrates dissolved solids through evaporation. The use of evaporation ponds to get salt from seawater is one of the oldest applications of solar energy. Modern uses include saltwater solutions used in leach mining and removal of dissolved solids from waste streams. Clothes lines, clotheshorses, and clothes dry clothes rack through evaporation by wind and sunlight without consuming electricity or gas. In some states in the United States the law protects clothing "the right to dry". The glossary transponder collector (UTC) is a downward-facing wall used for preheat air heating. UTC can raise incoming air temperatures up to 22 Â ° C (40 Â ° F) and provide a 45-60 Â ° C outlet temperature (113-140 Â ° F). The short payback periods of the recorded collectors (3 to 12 years) make them a more cost-effective alternative to glass collection systems. In 2003, more than 80 systems with a combined collector area of ​​35,000 square meters (380,000 sq ft) were installed worldwide, including the collected 860 m 2 (9,300 sq ft) in Costa Rica. to dry coffee beans and 1,300m 2 (14,000 sq ft) in Coimbatore, India, used to dry marigolds.
Water treatment
Solar distillation can be used to make salt water or brackish water. The first recorded example is by a 16th century Arabic alchemist. A large-scale solar refinery project was first built in 1872 in the Chilean mining town of Las Salinas. The factory, which has a 4,700m 2 solar collection (51,000 sqÃ, ft), can produce up to 22,700 L (5,000 Ã, Â ° imp gal? 6,000 US gal) per day and operate for 40 years. Individual designs still include single-slope, double-slope (or greenhouse type), vertical, cone, reverse absorbent, multi-axis, and double effects. It can still operate in passive, active, or hybrid mode. Double-slope stills are the most economical for decentralized domestic purposes, while some active effect units are more suitable for large-scale applications.
Solar water disinfection (SODIS) involves exposing a plastic polyethylene terephthalate (PET) bottle containing water to sunlight for several hours. Exposure times vary depending on weather and climate from a minimum of six hours to two days during full cloud conditions. Recommended by the World Health Organization as a viable method for household water treatment and safe storage. More than two million people in developing countries use this method for their daily drinking water.
Solar energy can be used in water stabilization ponds to treat wastewater without chemicals or electricity. The further environmental advantage is that algae grow in such ponds and consume carbon dioxide in photosynthesis, although algae can produce toxic chemicals that make water unusable.
Liquid Salt Technology
Liquid salts can be used as a method of storing thermal energy to sustain the thermal energy collected by the sun tower or sun mantle of a concentrated solar power plant, so it can be used to generate electricity in bad weather or at night. It was shown in the Solar Two project from 1995-1999. The system is estimated to have an annual efficiency of 99%, a reference to stored energy by storing heat before turning it into electricity, rather than converting direct heat into electricity. The mixture of molten salt varies. The longest mixture contains sodium nitrate, potassium nitrate, and calcium nitrate. It is non-flammable and non-toxic, and has been used in the chemical and metals industries as a heat transport fluid, so experience with such systems exists in non-solar applications.
Salt melts at 131 ° C (268 ° F). This stored liquid at 288 Ã, Â ° C (550Ã, Â ° F) in an isolated "cold" storage tank. The molten salt is pumped through a panel in the solar collector where the focused sun heats it to 566 ° C (1,051 ° F). Then sent to the heat storage tank. It is so well insulated that the heat energy can be stored for a week.
When electricity is required, hot salt is pumped into a conventional steam generator to produce super steam for turbines/generators as used in any conventional coal, oil, or nuclear power plant. The 100-megawatt turbine will require a tank of approximately 9.1 meters (30 feet) and 24 meters (79Ã, ft) in diameter to drive it for four hours with this design.
Some parabolic through power plants in Spain and SolarReserve solar tower developers use this thermal energy storage concept. Solana Generating Station in the US has six hours of storage with molten salt. The MarÃÆ'a Elena plant is a 400Ã-thermo-solar complex, MW in the northern Chilean region of Antofagasta using liquid salt technology.
Electricity production
Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). The CSP system uses a lens or mirror and tracking system to focus a large area of ​​sunlight into a small beam. PV converts light into electric current using a photoelectric effect.
Solar power is expected to be the world's largest power source by 2050, with solar photovoltaic and concentrated solar power accounting for 16 and 11 percent to global consumption as a whole. By 2016, after a year of rapid growth, solar power generates 1.3% of global power.
Commercialized concentrated solar power generation was first developed in the 1980s. The 392 MW 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 Solnova Solar Power Station 150 MW and Andasol 100 MW solar power plant, both in Spain. 250 MW Agua Caliente Solar Project, in the United States, and 221 MW Charanka Solar Park in India, is the world's largest photovoltaic factory. Solar power projects that exceed 1 GW are being developed, but most of the deployed photovoltaics are in a small roof arrangement of less than 5 kW, connected to the network using clean metering and/or feed-in rates.
Photovoltaics
In the last two decades, photovoltaics (PV), also known as solar PV, has evolved from a pure niche market of small scale applications into a major power source. Solar cells are devices that convert light directly into electricity using a photoelectric effect. The first solar cell was built by Charles Fritts in the 1880s. In 1931 a German engineer, Dr. Bruno Lange, developed photo cells using silver selenide in place of copper oxide. Although selenium cell prototypes converted less than 1% of light incident into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery. Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin invented crystalline silicon solar cells in 1954. These early solar cells cost 286 USD/watt and achieved an efficiency of 4.5-6%. In 2012, the available efficiency exceeds 20%, and the maximum efficiency of photovoltaics research is over 40%.
Solar power is concentrated
Concentrating Solar System (CSP) uses a lens or mirror and a tracking system to focus a large area of ​​sunlight into a small beam. Concentrated heat is then used as a heat source for conventional power plants. Various concentrating technologies exist; the most developed are parabolic troughs, linear concentrating linear fresnel, Stirling dish and solar power tower. Various techniques are used to track the Sun and focus light. In all these systems the working fluid is heated by concentrated sunlight, and then used for power generation or energy storage.
Architecture and city planning
Sunlight has influenced building design since the beginning of architectural history. Sophisticated solar architecture and urban planning methods were first used by Greeks and Chinese, who oriented their buildings southward to provide light and warmth.
A common feature of passive solar architecture is the relative orientation to the Sun, a compact proportion (low surface area ratio to volume), selective shelter (overhang) and thermal mass. When these features are tailored to the local climate and environment, they can produce a bright enough space that is within comfortable temperature range. Megaron Socrates's house is a classic example of a passive solar design. The latest approach to solar design uses computer modeling that binds together solar lighting, heating and ventilation systems in an integrated solar design package. Active solar equipment such as pumps, fans and replaceable windows can complement passive design and improve system performance.
Urban hot island (UHI) is a metropolitan area with higher temperatures than the surrounding environment. Higher temperatures result from increased solar energy absorption by urban materials such as asphalt and concrete, which have lower albedo and higher heat capacity than those in the natural environment. A simple method to counteract the effects of UHI is to paint buildings and white roads, and to plant trees in the area. Using this method, the hypothetical "cool community" program in Los Angeles has projected that urban temperatures can be reduced by about 3 Â ° C to an estimated cost of US $ 1 billion, providing an estimated total annual benefit of US $ 530 million from reductions in AC costs and savings health care.
Agriculture and horticulture
Agriculture and horticulture seek to optimize the capture of solar energy to optimize crop productivity. Techniques such as timed planting cycles, adjusted line orientation, high altitudes between rows and mixed crop varieties can increase yields. While sunlight is generally considered an abundant resource, exceptions highlight the importance of solar energy for agriculture. During the short growth season in the Little Ice Age, French and English farmers use fruit walls to maximize the collection of solar energy. This wall acts as a thermal mass and maturation is accelerated by keeping the plant warm. Early fruit walls were constructed perpendicular to the ground and facing south, but over time, a sloping wall was developed to make better use of sunlight. In 1699, Nicolas Fatio de Duillier even suggested using a tracking mechanism that could spin following the Sun. Solar energy applications in agriculture apart from planting crops include pumping water, drying crops, brooding chicks and drying chicken manure. Recently the technology has been embraced by vintners, which use the energy produced by solar panels to suppress the power of wine.
Greenhouses convert sunlight into heat, allowing year-round production and growth (in closed environments) of special crops and other plants not suited to the local climate. The primitive greenhouses were first used during Roman times to produce year-round cucumbers for the Roman emperor Tiberius. The first modern greenhouse built in Europe in the 16th century to keep exotic plants brought back from exploration abroad. Greenhouses remain an important part of current horticulture, and plastic transparent materials have also been used for the same effect in polytunnels and line coverings.
Transport
The development of solar-powered cars has been an engineering destination since the 1980s. World Solar Challenge is a bi-annual solar-powered car race, where teams from universities and companies compete more than 3,021 kilometers (1,877 mi) across central Australia from Darwin to Adelaide. In 1987, when it was established, the average speed of the winner was 67 kilometers per hour (42 mph) and in 2007 the average speed of the winner has increased to 90.87 kilometers per hour (56.46 mph). The planned North American Solar Challenge and South African Solar Challenge are comparable competitions that reflect international interest in the engineering and development of solar powered vehicles.
Some vehicles use solar panels for additional power, such as for air conditioning, to keep the interior cool, thereby reducing fuel consumption.
In 1975, the first practical solar vessel was built in England. In 1995, passenger ships incorporating PV panels began to emerge and are now used extensively. In 1996, Kenichi Horie conducted the first solar power crossing in the Pacific Ocean, and the Sun21 catamaran made the first solar-powered crossing of the Atlantic Ocean in winter 2006-2007. There are plans to circumnavigate the globe in 2010.
In 1974, an unmanned Sunrise AstroFlight aircraft made its first solar flight. On April 29, 1979, Solar Riser made its first flight in a solar-powered flying machine, fully controlled, carrying man, reaching a height of 40Ã, ft (12 m). In 1980, Gossamer Penguin made the first flight driven only by photovoltaics. This was quickly followed by the Solar Challenger that crossed the English Channel in July 1981. In 1990 Eric Scott Raymond in 21 hops flew from California to North Carolina using solar power. The development then returned to unmanned aerial vehicle (UAV) with Pathfinder (1997) and the subsequent design, culminating in Helios setting the record for non-rocket altitude-pushing aircraft at 29,524 meters (96,864 ft) in 2001. The Zephyr , developed by BAE Systems, was the latest in the record-breaking line of solar planes, made the flight for 54 hours in 2007, and the one-month flight imaginable in the year 2010. In 2016, Solar Impulse, an electric plane, currently circumnavigates the globe. It is a one-seater plane powered by solar cells and capable of taking off under its own power. The design allows airplanes in the air for several days.
The solar balloon is a black balloon filled with ordinary air. As the sunlight shines on the balloon, the air inside is heated and expands causing upward buoyant force, like an artificial hot air balloon. Some solar balloons are large enough for human flights, but usage is generally limited to the toy market since the surface area for relatively high load-to-weight ratio.
Fuel production
The chemical process of the sun uses solar energy to induce chemical reactions. This process offsets the energy that should come from fossil fuel sources and can also convert solar energy into fuel that can be stored and transported. The solar-induced chemical reaction can be divided into thermochemistry or photochemistry. Various fuels can be produced by artificial photosynthesis. The multielectron catalytic chemistry involved in the manufacture of carbon-based fuels (such as methanol) from carbon dioxide reduction is a challenge; a viable alternative is the production of hydrogen from protons, although the use of water as a source of electrons (like plants) requires the mastery of multi-electron oxidation from two water molecules to oxygen molecules. Some have envisioned the work of diesel fuel plants in coastal metropolitan areas by 2050 - seawater separation provides hydrogen to run through adjacent fuel cell power plants and purified water by the product going directly to the municipal water system. Another vision involves all the human structures that cover the surface of the earth (ie roads, vehicles and buildings) doing photosynthesis more efficiently than plants.
Hydrogen production technology has been a field of significant solar chemical research since the 1970s. In addition to electrolysis driven by photovoltaic or photochemical cells, several thermochemical processes have also been explored. One such route uses a concentrator to break water into oxygen and hydrogen at high temperatures (2,300-2,600 Â ° C or 4,200-4,700 Â ° F). Another approach uses heat from a solar concentrator to drive natural gas vapor reforms thus increasing overall hydrogen yield compared to conventional reform methods. The thermochemical cycle characterized by the decomposition and regeneration of reactants represents another pathway for hydrogen production. The Solzinc process under development at the Weizmann Institute of Science uses a 1 MW solar furnace to decompose zinc oxide (ZnO) at temperatures above 1,200 ° C (2,200 ° F). This initial reaction produces pure zinc, which can then be reacted with water to produce hydrogen.
Energy storage method
Thermal mass systems can store solar energy in the form of heat at a temperature that is useful domestically for daily or interseasonal periods. Thermal storage systems generally use available materials with high specific heat capacity such as water, soil and rock. Well-designed systems can decrease peak demand, shift usage times out of peak hours and reduce overall heating and cooling needs.
Phase change materials such as paraffin wax and Glauber salt are other thermal storage media. These materials are inexpensive, available, and can provide a useful temperature domestically (about 64 ° C or 147 ° F). The "Dover House" (in Dover, Massachusetts) was the first to use the Glauber salt heating system, in 1948. Solar energy can also be stored at high temperatures using molten salt. Salt is an effective storage medium because of its low cost, has a high specific heat capacity and can produce heat at temperatures in accordance with conventional power systems. The Solar Two project uses this energy storage method, which allows it to store 1.44 terajoules (400,000 kWh) in its storage tank of 68 m³ with an annual storage efficiency of about 99%.
Off-grid PV systems have traditionally used rechargeable batteries to store excess electricity. With a grid-tied system, excess electricity can be sent to the transmission network, while standard network electricity can be used to address deficiencies. The net measurement program provides a household credit system for each of the electricity they supply to the power grid. This is handled by 'rolling back' the meter every time the house generates more electricity than it consumes. If net electricity usage is below zero, the utility then rolls over the kilowatt hour pulse to the next month. Another approach involves the use of two meters, to measure the electricity consumed vs. electricity produced. This is less common because of the increased installation cost of the second meter. Most standard meters measure accurately in both directions, making the second meter unnecessary.
The pump-hydroelectric storage stores energy in the form of pumped water when energy is available from the lower elevation reservoir to the higher elevation. Energy recovers when demand is high by releasing water, with pumps becoming hydroelectric.
Development, deployment and economy
Beginning with the surge in coal use that accompanies the Industrial Revolution, energy consumption is constantly changing from wood and biomass to fossil fuels. The early development of solar technology began in the 1860s fueled by the hope that coal would soon become scarce. However, the development of solar technology stagnated in the early 20th century in the face of increasing availability, economy, and utility of coal and petroleum.
The 1973 oil embargo and the 1979 energy crisis led to the reorganization of energy policies worldwide and brought new attention to the development of solar technology. The deployment strategy focuses on incentive programs such as the US Federal Photovoltaics Utilization Program and the Sunlight Program in Japan. Other efforts include the establishment of research facilities in the US (SERI, now NREL), Japan (NEDO), and Germany (Fraunhofer Institute for ISE Solar Energy Systems).
Commercial solar water heaters began to appear in the United States in the 1890s. The system saw increased usage until 1920 but was gradually replaced by cheaper and more reliable heating fuel. Like photovoltaics, solar water heaters attracted renewed attention as a result of the oil crisis in the 1970s but interest subsided in the 1980s due to falling oil prices. Development in the solar water heating sector continued to grow throughout the 1990s and an average annual growth rate of 20% since 1999. Although generally underestimated, solar water heating and cooling is by far the most widely used solar technology with an estimated capacity of 154 GW per year. 2007.
The International Energy Agency has said that solar energy can make a major contribution to solving some of the most pressing problems facing the world today:
The development of affordable, inexpensive and clean solar energy technologies will have great long-term benefits. This will enhance the energy security of nations through dependence on indigenous, inexhaustible and largely independent-import resources, increasing sustainability, reducing pollution, lowering climate change mitigation costs, and keeping fossil fuel prices lower than vice versa. This advantage is global. Therefore, incremental incentive costs for initial placement should be considered investment investments; they should be wisely spent and need to be shared widely.
In 2011, a report by the International Energy Agency found that solar energy technologies such as photovoltaics, solar hot water and concentrated solar power can provide one-third of the world's energy by 2060 if politicians are committed to curbing climate change. Energy from the sun can play a key role in the de-carbonization of the global economy alongside improvements in energy efficiency and costing emitters of greenhouse gases. "The power of the sun is an incredible variation and application flexibility, from small to large scale".
We have proven... that once our oil and coal stores run out, mankind can receive unlimited power from the sun.
ISO standard
The International Organization for Standardization has established several standards relating to solar energy equipment. For example, ISO 9050 is associated with glass in buildings while ISO 10217 is associated with materials used in solar water heaters.
See also
Note
References
External links
- "How Does Photovoltaics Work?". NASA.
- Renewable Energy: Solar in Curlie (based on DMOZ)
- Solar Energy Back in the Day - a slideshow by Life magazine
- US. Map of Solar Farm (1 MW or Higher)
- Online Resource Database on Solar in Developing Countries
- Online resources and news from the non-profit American Energy Institute
- "Journal article tracks dramatic progress in solar efficiency". SPIE Newsroom . Retrieved November 4 2015 .
Source of the article : Wikipedia
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