Wind power is the use of airflow through a wind turbine to a mechanical power generator for electricity. Wind power, as an alternative to burning fossil fuels, abundant, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, does not consume water, and uses less land. The net effect on the environment is much less problematic than non-renewable resources.
The wind farm consists of many individual wind turbines, which are connected to a power transmission network. Ground is a cheap, competitive source of electricity with or in many places cheaper than coal or gas. Offshore winds are more stable and stronger than onshore and offshore farms have less visual impact, but construction and maintenance costs are much higher. Smallland wind farms can either energize the power grid or provide electricity for isolated off-grid locations.
Wind power provides variable power, which is very consistent from year to year but has significant variations over a shorter time scale. It is therefore used in conjunction with other power sources to provide a reliable supply. As the proportion of wind power in a region increases, the need to update the grid and decrease the ability to replace conventional production may occur. Power management techniques such as overcapacity, geographically distributed turbines, removable support sources, sufficient hydroelectric power, exporting and importing electricity to adjacent areas, or reducing demand when wind production is low, can in many cases address this problem. In addition, weather forecasts allow the power grid to be prepared for predictable variations in production.
In 2015, Denmark produces 40% of its electricity from wind, and at least 83 other countries around the world use wind power to supply their power grids. In 2014, global wind power capacity increased 16% to 369,553 MW. Annual wind energy production is also growing rapidly and has reached about 4% of the world's electricity use, 11.4% in the EU.
Video Wind power
Histori
Wind power has been used as long as humans place the screen into the wind. For more than two millennia wind-powered engines have ground granules and pumped water. Wind power is widely available and not limited to fast-flowing, or slow, streams that require fuel sources. Wind-powered pumps dry up polders in the Netherlands, and in dry areas such as in the northwestern United States or inland Australia, wind pumps provide water for livestock and steam engines.
The first windmill used for power production was built in Scotland in July 1887 by Prof. James Blyth of Anderson's College, Glasgow (pioneer of Strathclyde University). Blyth's 10-meter (33 ft) tall, sail-fabric wind turbine is installed in his holiday cottage garden at Marykirk in Kincardineshire and used to fill the accumulator developed by French Camille Alphonse Faure, to turn on the lights in the cottage, making it the first home in the world that has electric power supplied by wind power. Blyth offered electricity surplus to Marykirk people for street lighting, however, they declined the offer because they thought electricity was "the work of the devil." Although he later built a wind turbine to supply emergency power to Lunatic Asylum, Infirmary, and Dispenser of Montrose, the discovery was never really caught because the technology was not considered economically viable.
Across the Atlantic, in Cleveland, Ohio, a larger and highly engineered engine was designed and built in the winter of 1887-1888 by Charles F. Brush, was built by his engineering company at his home and operated from 1886 to 1900. Brush wind turbines has a rotor 17 meters (56Ã, ft) in diameter and mounted on an 18 meter (59Ã, ft) tower. Though large by today's standards, the engine is only rated 12 kW. The connected dynamo is used to charge the battery bank or operate up to 100 incandescent light bulbs, three arc lamps, and various motors in the Brush lab.
With the development of electric power, wind power finds new applications in lighting buildings that are far from the power generated center. Along parallel paths of the 20th century developed small wind stations suitable for agriculture or shelter, and larger utility-scale wind generators that can be connected to power grids for the long-distance use of power. Currently, wind powered generators operate in any size range between small stations for charging in isolated residences, to large gigawatt offshore wind farms that provide electricity for the national grid.
Maps Wind power
Wind farm
The wind farm is a group of wind turbines in the same location used for power production. A large wind farm may consist of several hundred individual wind turbines that are distributed over a large area, but the soil between turbines can be used for agricultural or other uses. For example, Gansu Wind Farm, the largest wind farm in the world, has several thousand turbines. A wind farm can also be found offshore.
Almost all large wind turbines have the same design - the horizontal axis wind turbine has a three-bladed rotor against the wind, attached to the nacelle above the tall tubular tower.
In a wind farm, individual turbines are interconnected with medium voltage (often 34.5 kV), power collection systems and communication networks. In general, the 7D distance (7 ÃÆ'â € "Rotor Diameter of the Wind Turbine) is set between each turbine in a fully developed wind farm. At the substation, this medium voltage current increases in voltage with the transformer for connection to a high voltage electrical power transmission system.
Characteristics and stability of the generator
Induction generators, often used for wind power projects in the 1980s and 1990s, require reactive power for excitation so that substations used in wind power collection systems include substantial capacitor banks for power factor correction. Different types of wind turbine generators behave differently during transmission network disruptions, so the extensive modeling of dynamic electromechanical characteristics of new wind farms is required by the transmission system operators to ensure stable behavior that can be predicted during system errors. In particular, induced generators can not support system voltages during errors, unlike synchronous generators driven by steam or hydro turbine.
Currently this generator is not used anymore in modern turbines. By contrast today most turbines use variable-speed generators combined with partial or full power converters between turbine generators and collector systems, which generally have more desirable properties for network interconnection and have low voltage rise capabilities. The modern concept uses a double-fed machine with a partial-scale converter or squirrel cage induction generator or a synchronous generator (either permanently or electrically) with a full-scale converter.
The transmission system operator will supply wind power generators with a grid code to determine the interconnection requirements to the transmission network. This will include the power factor, constant frequency and dynamic behavior of wind farm turbines during a system error.
Offshore wind power
Offshore wind power refers to the construction of wind farms in large bodies of water to generate electricity. This installation can take advantage of the more frequent and powerful winds available in these locations and have less aesthetic impact on the landscape than on land-based projects. However, construction and maintenance costs are much higher.
Siemens and Vestas are the leading turbine suppliers for offshore wind power. DONG Energy, Vattenfall, and E.ON are the leading offshore operators. As of October 2010, 3.16 GW offshore wind power capacity operates, especially in Northern Europe. According to BTM Consult, more than 16 GW of additional capacity will be installed before the end of 2014 and the UK and Germany will be the two major markets. Offshore wind power capacity is expected to total 75 GW worldwide by 2020, with significant contributions from China and the US. British investment in offshore wind power has resulted in a rapid decline in coal use as an energy source between 2012 and 2017, as well as a decline in the use of natural gas as an energy source by 2017.
In 2012, 1,662 turbines in 55 offshore wind farms in 10 European countries produce 18 TWh, enough to drive nearly five million households. In August 2013 the London Array in England is the largest offshore wind farm in the world at 630 MW.
Network collection and transmission
In a wind farm, individual turbines are interconnected with mid-voltage power collection systems (typically 34.5 kV) and communications networks. At the substation, this medium voltage current increases in voltage with the transformer for connection to a high voltage electrical power transmission system.
Transmission lines are needed to bring the power generated to the market (often far away). For off-shore stations this may require submarine cables. New high voltage channel construction may be too costly for wind resources alone, but wind sites can take advantage of installed lines for conventional fuel plants.
One of the biggest challenges today for the integration of wind power networks in the United States is the need to develop new transmission lines to bring electricity from wind farms, usually in the slightly populated state in the middle of the country due to the availability of winds, to high location loading, usually at beach where the population density is higher. Current transmission lines in remote locations are not designed for the transport of large amounts of energy. When the transmission line becomes longer, the losses associated with increased transmission of electricity, because the loss mode with a lower length is worsened and the new loss mode is no longer negligible because of its increasing length, making it more difficult to transport large loads over large distances. However, resistance from state and local governments makes it difficult to build new transmission lines. Multi-country power transmission projects are not recommended by countries with cheap power levels for fear that exporting their low-cost power will lead to increased tariffs. The 2005 energy law gave the Department of Energy authorities the authority to approve the transmission projects the state refused to act, but after attempts to use this authority, the Senate said the department was too aggressive in doing so. Another problem is that wind companies find out after the fact that the new agricultural transmission capacity is below generation capacity, especially since federal utility rules to encourage the installation of renewable energy allow feeder pathways to meet only the minimum standards. These are important issues that need to be solved, such as when the transmission capacity does not meet generating capacity, the wind farms are forced to produce below their full potential or stop walking together, in a process known as the curtailment. While this leads to untapped renewable generation potential, this prevents the possibility of network overload or the risk of reliable services.
Capacity and wind power production
By 2015, there are over 200,000 wind turbines in operation, with a total installed capacity of 432 GW worldwide. The EU has exceeded 100 GW nameplate capacity by September 2012, while the United States exceeded 75 GW by 2015 and the capacity connected to China's network goes through 145 GW by 2015. By 2015 wind power accounts for 15.6% of all generating capacity electricity installed in the EU and it generates about 11.4% of its power.
World wind generation capacity more than quadrupled between 2000 and 2006, doubling every 3 years. The United States spearheaded wind farms and led the world in installed capacity in the 1980s and entered the 1990s. In 1997 the installed capacity in Germany surpassed the United States and was headed until it was once again taken over by the United States in 2008. China has rapidly expanded the installation of the winds in late 2000 and passed the United States in 2010 to become a world leader. In 2011, 83 countries around the world use commercial wind power.
The actual amount of electricity that wind can generate is calculated by multiplying the capacity of the name plate by the capacity factor, which varies according to equipment and location. Estimated capacity factors for wind installations are in the range of 35% to 44%.
Growth trends
The wind power industry sets a new record by 2014 - more than 50 GW of new capacity has been installed. Another record-breaking year occurred in 2015, with an annual market growth of 22% producing a mark of 60 GW passing. By 2015, nearly half of all new wind power is added outside of traditional markets in Europe and North America. This is mostly from new development in China and India. The Global Wind Energy Council (GWEC) figures show that 2015 recorded an increase in installed capacity of over 63 GW, with total installed wind energy capacity being 432.9 GW, up from 74 GW in 2006. In terms of economic value, wind energy sector has become one of the most important players in the energy market, with total investment of US $ 329bn (EUR296.6bn), up 4% compared to 2014.
Although the wind power industry is affected by the global financial crisis in 2009 and 2010, GWEC predicts that the installed wind power capacity will be 792.1 GW by the end of 2020 and 4,042 GW by the end of 2050. Increased commissioning of wind power is accompanied by a record low price for upcoming renewable electric power. In some cases, terrestrial winds have become the cheapest power generation option and costs continue to decline. The contract price for ground breeze over the next few years is now as low as 30 USD/MWh.
In the European Union by 2015, 44% of all new generating capacity is wind power; while in the same period the capacity of clean fossil fuel power decreased.
Capacity factor
Because wind speed is not constant, annual wind energy production is never as much as the number of generator nameplate ratings multiplied by the total hours of the year. The actual productivity ratio in a year to theoretical maximum is called the capacity factor. Typical capacity factors are 15-50%; values ​​at the upper end of the range are achieved on profitable sites and due to wind turbine design improvements.
Online data is available for multiple locations, and capacity factors can be calculated from annual output. For example, the German national average wind power generation factor above all of 2012 is just under 17.5% (45,867 GWÃ, Â · h/yr/(29.9 GW ÃÆ'â € "24 ÃÆ'â €" 366) = 0.1746 ), and the capacity factor for Scottish wind farms averaged 24% between 2008 and 2010.
Unlike fuel-generated plants, the capacity factor is affected by several parameters, including on-site wind variability and generator size relative to the turbine sweep area. Smaller generators will be cheaper and achieve a higher capacity factor but will produce less power (and thus reduce profits) in high winds. In contrast, large generators will be more expensive but produce little additional power and, depending on the type, can stop at low wind speeds. Thus an optimum capacity factor of about 40-50% will be devoted to.
A 2008 study released by the US Department of Energy noted that new winds installation capacity factors are increasing as technology increases, and projecting further improvements to future capacity factors. In 2010, the department estimated the new wind turbine capacity factor in 2010 to 45%. The average annual capacity factor for wind generators in the US varies between 29.8% and 34% over the 2010-2015 period.
Penetration
The penetration of wind energy is the fraction of the energy produced by the wind compared to the total generation. Penetration of wind power in the world's power plants by 2015 is 3.5%.
There is no generally accepted maximum level of wind penetration. Limits for certain networks will depend on existing plants, pricing mechanisms, capacity for energy storage, demand management and other factors. An interconnected power grid will already include backup power and transmission capacity to enable equipment failure. This reserve capacity can also work to compensate for the various power plants generated by wind stations. Studies have shown that 20% of total annual electrical energy consumption can be combined with minimal difficulty. These studies have been conducted for locations with geographically dispersed wind farms, some removable energy levels or hydroelectric power plants with storage capacity, demand management, and interconnected to large grid areas that enable the export of electrical power when required. Beyond the 20% level, there are some technical limitations, but the economic implications become more significant. The electric utilities continue to study the effects of large-scale penetration on wind generation on system and economic stability.
The wind energy penetration rate can be determined for different time durations, but is often cited annually. To get 100% of the wind every year requires substantial long-term storage or substantial interconnection to other systems that may already have substantial storage. Monthly, weekly, daily, or hourly - or less - the wind may supply as much as or more than 100% of current usage, with the rest saved or exported. The seasonal industry may then take advantage of high winds and low usage times such as at night when wind output can exceed normal demand. Such industries may include the production of silicon, aluminum, steel, or natural gas, and hydrogen, and use long-term storage to facilitate 100% energy from variable renewable energy. The house can also be programmed to receive additional electrical power on demand, for example by powering the water heater thermostat remotely.
In Australia, the state of South Australia produces about half of the country's wind power capacity. By the end of 2011 wind power in South Australia, championed by Prime Minister (and Minister of Climate Change) Mike Rann, reaching 26% of the State powerhouse, crept out of coal for the first time. At this stage South Australia, with only 7.2% of Australia's population, has 54% of its installed capacity.
Variability
Electricity generated from wind power can vary greatly over several different time ranges: hourly, daily, or seasonally. Annual variations also exist, but are not significant. Because power generation and instantaneous consumption must remain balanced to maintain network stability, this variability can present a major challenge for incorporating large amounts of wind power into the grid system. Intermittent and inherent wind energy production properties can increase costs for regulation, additional operating reserves, and (at high penetration rates) may require upgrading existing energy demand management, load relief, storage solutions or system interconnection with HVDC cables. Wind variability is very different from the sun, wind may generate electricity at night when other baseload plants are often over-produced.
Load fluctuations and reserves for failure of large fossil fuel generating units require operating reserve capacity, which can be increased to compensate for wind generating variability.
Wind power varies, and during low wind periods must be replaced with other resources. The current transmission network overcomes other generation plant outages and daily changes in electricity demand, but intermittent resource variability such as wind power, more often than conventional power plants that, when scheduled to operate, may be able to transmit their name plate capacity of approximately 95% of time.
Currently, grid systems with large wind penetration require a slight increase in the frequency of use of natural gas spinning power plants to prevent loss of electric power if there is no wind. At low wind power penetration, this is less of a problem.
GE has installed a prototype wind turbine with an onboard battery that is similar to an electric car, equivalent to 1 minute of production. Although the capacity is small, it is sufficient to ensure that the power output matches the approximate for 15 minutes, since the battery is used to eliminate the difference rather than delivering full output. In certain cases, increased predictability can be used to take the penetration of wind power from 20 to 30 or 40 percent. The cost of the battery can be taken by selling the burst power on demand and reducing the reserve requirement of the gas generator.
In the UK there are 124 separate occasions from 2008 to 2010 when the country's wind output fell to less than 2% of installed capacity. A report on Danish wind power noted that their wind power network provided less than 1% of the 54-day average demand during 2002. Wind power supporters argue that this low wind period can be handled simply by reviving existing power stations that have has been held in readiness, or interlinked with HVDC. Power lines with slow-response thermal power plants and no ties to networks with hydroelectric power plants may have to limit the use of wind power. According to a 2007 Stanford University study published in the Journal of Meteorology and Applied Climatology, connecting ten or more wind farms could allow an average of 33% of the total energy produced (ie about 8% of the total nameplate capacity) to be used as reliable and reliable reliable electric power to handle peak loads, as long as minimum criteria are met for wind speed and high turbines.
Conversely, on windy days, even with a penetration rate of 16%, wind power plants can surpass all other power sources in a country. In Spain, in the early hours of April 16, 2012 wind power production reached the highest percentage of electricity production until then, amounting to 60.46% of total demand. In Denmark, which has a power market penetration of 30% by 2013, over 90 hours, wind power generates 100% of the country's power, peaking at 122% of the country's demand at 2 am on 28 October.
The International Energy Agency Forum 2006 presented the cost of managing intermittence as a function of the wind energy distribution of total capacity for several countries, as shown in the table on the right. Three reports of wind variability in the UK issued in 2009, generally agree that wind variability needs to be taken into account by adding 20% ​​to the operating reserves, but that does not make the network out of control. Additional costs, which are simple, can be quantified.
The combination of diversifying renewable energy variables by type and location, estimating the variation, and integrating it with renewable renewable energy, flexible fuel generators, and demand responses can create a power system that has the potential to reliably meet power supply needs. Integrating higher levels of renewable energy is successfully demonstrated in the real world:
In 2009, eight Americans and three European authorities, writing in a leading professional electrical engineer journal, found no "credible and powerful technical limits for the amount of wind energy that can be accommodated by the power grid". In fact, none of the more than 200 international studies, or official studies for the eastern and western regions of the US, as well as the International Energy Agency, have found substantial costs or technical barriers to reliably integrate up to 30% of renewable supply variables into the grid, and in some research is much more.
Solar power tends to be a complementary wind. At daily to weekly ranges, high-pressure areas tend to carry bright skies and low surface winds, while low-pressure areas tend to be firmer and more cloudy. On a seasonal time scale, the peak solar energy in summer, while in many areas, wind energy is lower in summer and higher in winter. So seasonal variations of wind and solar power tend to cancel each other out. In 2007, the Institute of Technology for Solar Energy Supply from the University of Kassel tested a combined power plant connecting solar, wind, biogas and hydrostorage to provide power that follows the flow over time and throughout the year, entirely from renewable sources.
Predictability
Wind power prediction methods are used, but the predictability of certain wind farms is low for short-term operations. For certain generators, there is a 80% chance that wind output will change less than 10% in one hour and 40% will likely change 10% or more in 5 hours.
However, a study by Graham Sinden (2009) suggests that, in practice, variations in thousands of wind turbines, scattered in several different sites and wind regimes, are smoothed out. As the distance between sites increases, the correlation between wind speed measured on the site, decreases.
Thus, while the output of a single turbine can vary greatly and rapidly as local wind speeds vary, as more turbines are connected in larger and larger areas, the average power output becomes less variable and more predictable.
Wind power is almost never subjected to major technical failures, since individual wind turbine failures have almost no effect on overall power, so wind power is distributed reliably and predictably, while conventional generators, while much less variable, can suffer large blackouts that can not predicted.
Energy storage
Typically, conventional hydroelectric equips wind power very well. When the wind is strong, the nearest hydroelectric station can hold their water for a while. When winds down they can, as long as they have generating capacity, quickly increase production to compensate. It provides a very uniform power supply and almost no energy loss and does not use more water.
Alternatively, if a suitable water head is not available, a pumped hydroelectricity or other form of grid energy storage such as compressed air energy storage and thermal energy storage can store energy developed during high wind periods and release it when necessary. The type of storage required depends on the degree of wind penetration - low penetration requires daily storage, and high penetration requires short and long term storage - for a month or more. The stored energy increases the economic value of wind energy because it can be shifted to replace higher production costs during peak demand periods. The revenue potential of this arbitration may offset storage costs and losses. For example, in the UK, 1.7 GW Dinorwig's exported storage plants level the peak demand for electricity, allowing base load suppliers to run their plants more efficiently. Although the pumped-storage system is only about 75% efficient, and has high installation costs, low operating costs and the ability to reduce the required basic power loads can save fuel costs and total electricity generation costs.
In certain geographical areas, the peak wind speed may not correspond to peak demand for electrical power. In the US state of California and Texas, for example, hot summer days may have low wind speeds and high electricity demand due to the use of air conditioning. Some utilities subsidize the purchase of geothermal heat pumps by their customers, to reduce demand for electricity during the summer by making air conditioning up to 70% more efficient; The widespread adoption of this technology will be more in line with the demand for electric power for wind availability in areas with hot summers and low summer winds. The possible future option is to connect a widespread geographical area with a "super grid" HVDC. In the US it is estimated that to improve the transmission system to take up planned renewable energy or it may cost at least USD 60 billion, while the community value of additional wind power will be more than that cost.
Germany has an installed wind and solar capacity that can exceed daily demand, and has exported peak power to neighboring countries, with exports reaching approximately 14.7 billion kWh by 2012. A more practical solution is the installation of a thirty day storage capacity capable to supply 80% of demand, which will become necessary when most of Europe's energy is derived from wind and solar power. Just as the EU requires member states to maintain a 90-day strategic oil reserve it can be expected that countries will provide electricity storage, rather than expecting to use their neighbors to measure the net.
Credit capacity, fuel savings and energy return
The capacity of the wind credit is estimated by determining the capacity of conventional plants that are transferred by wind power, while maintaining the same level of system security. According to the American Wind Energy Association, wind power production in the United States in 2015 avoids consumption of 73 billion gallons of water and reduces CO 2 emissions by 132 million metric tons, while providing USD 7.3 billion in public health savings.
The energy needed to build a wind farm is divided into total output over its lifetime, Energy Return on Energy Invested, from wind power varies but averages about 20-25. So, the energy recovery time is usually about a year.
Economy
Wind turbines reach grid parity (the point at which wind power costs correspond to traditional sources) in some parts of Europe in the mid-2000s, and in the US at the same time. The fall in prices continues to drive cost reductions and it has been suggested that it has reached the general grid parity in Europe by 2010, and will reach the same point in the US around 2016 due to the expected decline in capital costs of around 12%.
Cost and power trends
Wind power is capital intensive, but does not have fuel costs. Therefore, the price of wind power is much more stable than the fossil fuel price that varies. The marginal cost of wind energy once a station is built is typically less than 1 cent per kWÃ, Â · h.
However, the average cost estimate per unit of electric power should incorporate the costs of constructing turbine and transmission facilities, loan funds, return to investors (including risk costs), annual production estimates, and other components, averaged over useful projections. equipment age, which may be more than twenty years old. Estimated energy costs depend heavily on these assumptions so that the published cost figures can differ substantially. In 2004, wind energy consumed one fifth of what it did in the 1980s, and some predicted that the downward trend would continue as larger multi-megawatt turbines were mass-produced. In 2012, the cost of capital for wind turbines is much lower than 2008-2010 but still above the level of 2002. A 2011 report from the American Wind Energy Association states, "Wind costs have fallen over the past two years, in the range of 5 to 6 cents per kilowatt-hour recently... about 2 cents cheaper than coal-fired power, and more projects financed through debt regulation rather than last year's equity tax structure... won more major receipts from Wall Street banks.... Equipment makers can also ship products in the same year they are ordered instead of waiting for up to three years just as in the previous cycle.... 5.600 MW of new installed capacity is being built in the United States, more than double the amount at this time in 2010. Thirty-five percent of all new power plants are built in the United States States since 2005 came from the wind, more than a combination of new gas and coal plants, as electricity providers are increasingly interested in winding as a comfortable hedge against unexpected commodity price movements. "
The British Wind Energy Association report gives an average cost of generating an average ground wind power of 3.2 pence (between US 5 and 6 cents) per kWÃ, Â · h (2005). The cost per unit of energy generated is estimated in 2006 to be 5 to 6 percent above the cost of new generation capacity in the US for coal and natural gas: wind costs estimated at $ 55.80 per MWÃ, Â · h, coal at $ 53, 10/MW Â · and natural gas at $ 52.50. Comparative results similar to natural gas were obtained in a government study in the UK in 2011. In 2011 electricity from wind turbines could have been cheaper than fossils or nuclear plants; it is also expected that wind power will be the cheapest form of energy generation in the future. The presence of wind energy, even when subsidized, can reduce costs to consumers (EUR5 billion/year in Germany) by reducing marginal prices, by minimizing the use of expensive peak power plants.
A 2012 EU study shows the basic cost of land-based wind power similar to coal, when subsidies and externalities are ignored. Wind power has some of the lowest external costs.
In February 2013, Bloomberg New Energy Finance (BNEF) reported that the cost of generating electricity from new wind farms is cheaper than new coal or new base load gas generators. When incorporating Australia's current federal government carbon pricing scheme, their model provides a $ 80/MWh (in Australian dollars) fee for new wind farms, $ 143/MWh for new coal mills and $ 116/MWh for new base load gas plants. Modeling also shows that "even without the carbon price (the most efficient way to reduce economic emissions) wind energy is 14% cheaper than new coal and 18% cheaper than new gas." The share of the higher costs for new coal mills is due to the high cost of financial loans due to "damaging reputation of solid investment investments". The cost of generating gas fired in part because of the "export market" effect on local prices. Production costs of coal-fired power plants built in the "1970s and 1980s" are cheaper than renewable energy sources because of depreciation. By 2015 BNEF calculates LCOE price per MWh energy in new power plants (excluding carbon costs) Ã,: $ 85 for overland wind ($ 175 for offshore), $ 66-75 for coal in America ($ 82-105 at Europe), gas $ 80-100. A study 2014 shows un-subsidized LCOE costs between $ 37-81, depending on the region. The US DOE 2014 report shows that in some cases, the price of power purchase agreements for wind power drops to a record low of $ 23.5/MWh.
Costs have been reduced because wind turbine technology has improved. There are now longer and lighter wind turbine blades, improved turbine performance and increased power generation efficiency. Also, the cost of project capital and wind maintenance continues to decline. For example, the wind industry in the United States in early 2014 is capable of producing more power at lower cost by using higher wind turbines with longer blades, capturing faster winds at higher altitudes. This has opened up new opportunities and in Indiana, Michigan, and Ohio, the price of power from wind turbines built 300 feet to 400 feet above ground can now compete with conventional fossil fuels such as coal. Prices have dropped to about 4 cents per kilowatt-hour in some cases and utilities have increased the amount of wind energy in their portfolio, saying it is their cheapest option.
A number of initiatives work to reduce the cost of electricity from offshore wind. One example is the Carbon Trust Offshore Wind Accelerator, a joint industry project, involving nine offshore wind developers, aiming to reduce offshore wind costs by 10% by 2015. It has been suggested that innovation on a scale can provide 25% cost reduction in offshore winds by 2020. Henrik Stiesdal, former Chief Technical Officer at Siemens Wind Power, has stated that by 2025 the energy of offshore winds will be one of the cheapest and scalable solutions in the UK, compared to renewable energy sources and energy sources of materials fossil fuel, if the actual costs to society are taken into account in the cost of energy equations. He calculated the cost at that time to 43 EUR/MWh for onshore, and 72 EUR/MWh for offshore wind.
In August 2017, the Department of Energy's National Renewable Energy Laboratory (NREL) publishes a new report on a 50% reduction in wind power costs by 2030. NREL is expected to achieve progress in wind turbine design, materials and controls to unlock performance improvements and reduce costs. According to international surveyors, the study shows that cost cuts are projected to fluctuate between 24% and 30% by 2030. In more aggressive cases, experts estimate cost reductions of up to 40 percent if research and development and technology programs generate additional efficiency.
Community incentives and benefits
The US wind industry generates tens of thousands of jobs and billions of dollars of economic activity. Wind projects provide local taxes, or payments in lieu of taxes and strengthen the economy of rural communities by providing income to farmers with wind turbines on their land. Wind energy in many jurisdictions receives financial or other support to foster its development. The benefits of wind energy from subsidizing in many jurisdictions, either to increase its appeal, or to compensate for subsidies received by other forms of production that have significant negative externalities.
In the US, wind power received a production tax credit (PTC) of 1.5  ¢/kWh in 1993 dollars for each kWh  · h produced, during the first ten years; 2.2 cents per kWÃ,  · h in 2012, credits renewed on 2 January 2012, to include construction starting in 2013. A 30% tax credit can be applied instead of receiving PTC. Another tax benefit is accelerated depreciation. Many American countries also provide incentives, such as exemption from property taxes, mandatory purchases, and additional markets for "green credit". The Energy Enhancement and Extension Act of 2008 contains extensions of credit for wind, including microturbines. Countries such as Canada and Germany also provide incentives for wind turbine construction, such as tax credits or minimum purchase prices for wind power, with guaranteed network access (sometimes referred to as feed-in rates). This feed-in rate is usually set well above the average price of electric power. In December 2013, US Senator Lamar Alexander and other Republican senators argued that "the wind energy production tax credit should be allowed to expire by the end of 2013" and ends January 1, 2014 for a new installation.
The strength of the secondary market also provides an incentive for companies to use the power generated by the wind, even if there is a premium price for electricity. For example, socially responsible companies pay premium utility companies used to subsidize and build new wind power infrastructure. Companies use the power generated by the wind, and in return they can claim that they make a strong "green" effort. In the US, Green-e organizations monitor business compliance with these renewable energy credits. Turbine prices have dropped significantly in recent years due to tight competitive conditions such as increased use of energy auctions, and the elimination of subsidies in many markets. For example, Vestas, a manufacturer of wind turbines, whose largest onshore turbine can pump 4.2 megawatts of power, enough to provide electricity for about 5,000 homes, has seen its turbine prices fall from EUR950,000 per megawatt by the end of 2016, to around EUR800,000 megawatt in the third quarter of 2017.
Small-scale wind power
Small scale wind power is the name given to wind power systems with the capacity to generate up to 50 kW of electrical power. An isolated community, which may rely on diesel generators, may use wind turbines as an alternative. Individuals may purchase this system to reduce or eliminate their dependence on power grids for economic reasons, or to reduce their carbon footprint. Wind turbines have been used for household power generation along with battery storage for decades in remote areas.
Recent examples of small-scale solar wind projects in urban areas can be found in New York City, where, since 2009, a number of building projects have closed their roofs with the Gorlov helical wind turbine. Although the energy they generate is small compared to the overall consumption of the building, they help strengthen the 'green' credibility of the building in a way that "shows to your high-tech boiler people" can not, with some projects also receiving direct support from the Agency for Energy Research and Development New York State.
Domestic wind turbines connected to the network can use grid energy storage, thereby replacing locally-produced power supply with locally available power when available. The excess power generated by domestic microgenerators can, in some jurisdictions, be put into the network and sold to utility companies, generating retail credit for owners of microgenerators to offset their energy costs.
Users of off-grid systems can adapt to intermittent power or use batteries, photovoltaic or diesel systems to supplement wind turbines. Equipment such as parking meters, traffic alerts, street lighting, or wireless Internet gateways may be supported by small wind turbines, possibly combined with photovoltaic systems, which charge a small battery to replace the need for connection to the power grid.
A Carbon Trust study into small-scale wind energy potential in the UK, published in 2010, found that small wind turbines can provide up to 1.5 terawatt hours (TW Â · h) per year of electric power (0.4% of total UK electricity power consumption), saving 0.6 million tons of carbon dioxide (Mt CO 2 ) emissions savings. This is based on the assumption that 10% of households will install turbines at competitive costs with the power grid, about 12 cents (US 19 cents) per kW Ã, Â · h. A report prepared for the government-sponsored Energy Saving Trust in the UK in 2006 found that electrical generators from different types of homes can provide 30 to 40% of the country's electricity needs by 2050.
The distributed generation of renewable resources is increasing as a consequence of increasing awareness of climate change. The electronic interface required to connect a utility generator unit that can be updated with the utility system may include additional functions, such as active filtering to improve power quality.
Environmental effects
The environmental impact of wind power when compared to the environmental impact of fossil fuels is relatively small. According to the IPCC, in assessing the potential for global warming of the life cycle of energy sources, wind turbines have a median value between 12 and 11 (gCO 2 eq/kWh) depending on whether off-or ground turbines are being assessed. Compared to other low carbon resources, wind turbines have some of the lowest global warming potential per unit of electrical energy generated.
While wind farms can cover large areas of land, many land uses such as agriculture are compatible with them, as only a small portion of the foundation and turbine infrastructure are not available for use.
There are reports of bird and bat mortality in wind turbines as they are around other artificial structures. The scale of the ecological impact may or may not be significant, depending on the particular circumstances. Prevention and mitigation of wildlife deaths, and protection of peat swamps, affect the determination of the location and operation of wind turbines.
The wind turbine generates some noise. At a distance of 300 meters (980 feet), this may be around 45dB, which is a bit louder than the refrigerator. At a distance of 1.5 km (1 mi) they become inaudible. There are anecdotal reports about the negative health effects of noise on people living very close to wind turbines. Research peer reviewed generally does not support this claim.
The United States Air Force and Navy have expressed concern that the determination of the location of large wind turbines near the base "will have a negative impact on the radar so that air traffic controllers will lose the plane's location."
The aesthetic aspect of the wind turbine and the transformation of the visual landscape produced is very significant. Conflicts appear primarily in landscaped protected and protected by historical heritage.
Politics
Central government
Nuclear power and fossil fuels are subsidized by many governments, and wind power and other forms of renewable energy are also often subsidized. For example, a 2009 study by the Institute of Environmental Law assessed the size and structure of US energy subsidies over the period 2002-2008. The study estimates that subsidies for fossil fuel based sources amount to about $ 72 billion during this period and subsidies for renewable fuel sources reach $ 29 billion. In the United States, the federal government has paid US $ 74 billion for energy subsidies to support R & D for nuclear power ($ 50 billion) and fossil fuels ($ 24 billion) from 1973 to 2003. Over this same time span, renewable energy technologies and energy efficiency received a total of US $ 26 billion. It has been suggested that subsidized shifts will help match the playing field and support the growth of the energy sector, which is solar, wind, and biofuels. History shows that no energy sector is developed without subsidies.
According to the International Energy Agency (IEA) (2011), energy subsidies artificially lower the energy prices paid by consumers, raise prices received by producers or lower production costs. "The cost of subsidizing fossil fuels is generally greater than the benefits: subsidies for renewable energy and low-carbon energy technologies can bring long-term economic and environmental benefits." In November 2011, the IEA report titled Spreading Renewable Energy 2011 says "subsidies in uncompetitive green energy technologies are justified to provide incentives to invest in technology with clear environmental and energy security benefits". The IEA report does not agree with claims that renewable energy technologies are only via via expensive subsidies and unable to generate energy reliably to meet demand.
However, the IEA's views are not universally accepted. Between 2010 and 2016, subsidies for winds range between 1.3 Â ¢ and 5.7 Â ¢ per kWh. Subsidies for coal, natural gas and nuclear all range from 0.05 Â ¢ and 0.2 Â ¢ per kWh over the years. On a per-kWh basis, winds are subsidized 50 times more than traditional sources.
In the US, the wind power industry has recently stepped up lobbying efforts considerably, spending about $ 5 million in 2009 after years of relative uncertainty in Washington. In comparison, the US nuclear industry alone spent more than $ 650 million on lobbying and campaign contributions over the ten-year period ending in 2008.
Following the 2011 Japan nuclear accident, the German federal government is drafting new plans to improve energy efficiency and renewable energy commercialization, with a particular focus on offshore wind farms. Under the plan, large wind turbines will be built away from the shoreline, where winds blow more consistently than on land, and where large turbines will not disrupt the population. The plan aims to reduce Germany's dependence on energy derived from coal and nuclear power plants.
Public opinion
Public attitudes surveys throughout Europe and in many other countries show strong public support for wind power. About 80% of EU residents support wind power. In Germany, where wind power has gained enormous social acceptance, hundreds of thousands of people have invested in citizen wind farms across the country and thousands of small and medium enterprises running successful businesses in new sectors that in 2008 employed 90,000 people. people and generates 8% of Germany's electricity.
Bakker et al. (2012) found in their study that when the inhabitants did not want the turbines to be near them, their pique was significantly higher than those who "benefit economically from wind turbines, the proportion of somewhat or significantly less significantly affected people".
Although wind power is a popular form of energy generation, wind farm construction is not universally accepted, often for aesthetic reasons.
In Spain, with few exceptions, there is little opposition to the installation of inland winds parks. However, projects to build offshore parks become more controversial. In particular, the proposal builds the world's largest offshore wind power production facility in southwestern Spain on the coast of CÃÆ'¡diz, where the Battle of 1805 from Trafalgar has met with strong opposition who fear for tourism and fisheries in the area, and because of the area is a war grave.
In a survey conducted by Angus Reid Strategies in October 2007, 89 percent of respondents said that using renewable energy sources such as wind or solar power is positive for Canada, because these sources are better for the environment. Only 4 percent are considered to use renewable sources as negative because they are reliable and expensive. According to a Saint Consulting survey in April 2007, wind power is the most likely alternative energy source to gain public support for future development in Canada, with only 16% opposing this type of energy. In contrast, 3 out of 4 Canadians oppose the development of nuclear power.
A 2003 survey of people living in about 10 Scottish wind farms found a high level of community acceptance and strong support for wind power, with much support from those living closest to the wind farm. The results of the survey support the previous survey of Scottish Executive Executive of 'Public Attitudes to the Environment in Scotland 2002', which found that Scottish society would prefer most of their electricity to come from renewable energy, and which rated the wind power as the cleanest source of renewable energy. A survey conducted in 2005 showed that 74% of people in Scotland agree that wind farms are needed to meet current and future energy needs. When people were asked the same question in Scottish renewable energy research conducted in 2010, 78% agreed. This increase is significant because there are twice as many wind farms in 2010 as it was in 2005. The 2010 survey also showed that 52% disagree with the statement that wind farms are "ugly and stains on the landscape". 59% agree that wind farms are needed and how they look unimportant. Regarding tourism, query responders consider electricity poles, cell phone towers, quarries and plantations more negative than wind farms. Scotland plans to get 100% power from renewable sources by 2020.
In other cases there is a direct community ownership of wind farm projects. Hundreds of thousands of people who have been involved in German small and medium wind farms show such support there.
The Poll Harris 2010 reflects strong support for wind power in Germany, other European countries, and the US.
Community
Many wind power companies work with local communities to reduce environmental and other problems associated with certain wind farms. In other cases there is a direct community ownership of wind farm projects. Appropriate government consultation, planning, and approval procedures also help minimize environmental risks. Some may still object to wind farms but, according to The Australia Institute, their concerns should be weighed against the need to address the threat posed by climate change and opinions from the wider community.
In America, wind projects are reported to increase local tax bases, help pay for schools, roads, and hospitals. Wind projects also revitalize the economy of rural communities by providing regular income to farmers and other landowners.
In the UK, both the National Trust and the UK Campaign for Protecting the UK have expressed concern about the effects on rural landscapes caused by improper wind turbines and wind turbines.
Several wind farms have become tourist attractions. The Whitelee Wind Farm Visitor Center features exhibition halls, learning centers, cafes with observation decks and shops. Run by the Glasgow Science Center.
In Denmark, losing schemes give people the right to claim compensation for the loss of their property value if it is caused by its proximity to wind turbines. Losses must be at least 1% of property value.
Despite the general support for the concept of wind power in society in general, local opposition often exists and has delayed or canceled a number of projects. For example, there are concerns that some installations may adversely affect TV and radio reception and Doppler weather radar, and result in excessive sound and vibration levels leading to declining property values. Potential receive-broadcast solutions include predictive interference modeling as a site selection component. A study of 50,000 home sales near wind turbines found no statistical evidence that prices were affected.
While aesthetic issues are subjective and some find a pleasant and optimistic wind farm, or a symbol of energy independence and local prosperity, protest groups are often set up to try to block new wind power sites for various reasons.
This type of opposition is often described as NIMBYism, but research conducted in 2009 found that there is little evidence to support the belief that residents simply object to renewable power facilities such as wind turbines as a result of the "No in My Backyard" attitude.
Turbine design
Wind turbines are devices that convert kinetic energy into wind power. The results of more than a millennium of windmill development and modern engineering, today's wind turbines are manufactured in a variety of horizontal axes and vertical axis types. The smallest turbine is used for applications such as battery charging for additional power. A slightly larger turbine can be used to make small contributions to the domestic power supply while reselling unused power to utility suppliers through the power grid. Large turbine arrays, known as wind farms, have become an increasingly important source of renewable energy and are being used in many countries as part of a strategy to reduce their dependence on fossil fuels.
The design of wind turbines is the process of defining the shape and specification of wind turbines to extract energy from the wind. The wind turbine installation consists of the systems needed to capture wind energy, direct the turbine to the wind, convert mechanical spins into electric power, and other systems to start, stop, and control the turbine.
In 1919 the German physicist Albert Betz pointed out that for an ideal hypothetical wind energy extraction engine, the fundamental law of conservation of mass and energy allows no more than 16/27 (59.3%) of wind kinetic energy to be captured. This Betz limit can be approached in modern turbine designs, which can reach 70 to 80% of the theoretical Betz limit.
Aerodynamic wind turbine is not easy. The airflow on the blade is not the same as the airflow away from the turbine. The nature of the energy extracted from the air also causes air to be deflected by the turbine. In addition, the aerodynamic wind turbine on the rotor surface shows a phenomenon that is rarely seen in other aerodynamic fields. The shape and dimensions of the blades of the wind turbine are determined by the aerodynamic performance required to efficiently extract energy from the wind, and with the force required to withstand the force on the blade.
In addition to the aerodynamic design of the blade, the design of a complete wind power system should also address the design of the rotor hub installation, nacelle, tower structure, generator, control, and foundation. Turbine design makes extensive use of computer modeling and simulation tools. This is becoming increasingly sophisticated as highlighted by recent cutting-edge studies by Hewitt et al. Further design factors should also be considered when integrating wind turbines into the power grid.
Wind energy
Energi angin adalah energi kinetik dari udara yang bergerak, juga disebut angin. Total energi angin yang mengalir melalui permukaan imajiner dengan area A selama waktu t adalah:
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