Potential for Wind-Generated Electricity in China[2009]

风能的发展潜力英语作文The Untapped Potential of Wind EnergyAs the world grapples with the pressing issues of climate change and the need for sustainable energy sources, the development of wind energy has emerged as a promising solution. Wind power, a clean and renewable form of energy, has the potential to play a pivotal role in shaddressing the global energy crisis and reducing our carbon footprint.One of the primary advantages of wind energy is its abundance and accessibility. The wind, a natural and perpetual resource, is available in various regions around the globe, making it a widely accessible source of energy. Unlike fossil fuels, which are finite and unevenly distributed, wind energy can be harnessed wherever the wind blows, providing a more equitable and decentralized approach to energy generation.Moreover, the environmental benefits of wind power are undeniable. Unlike traditional fossil fuel-based power plants, wind turbines do not emit greenhouse gases, pollutants, or other harmful byproducts during the energy generation process. This makes wind energy aclean and sustainable alternative, contributing to the reduction of carbon emissions and the mitigation of climate change.The technological advancements in wind energy have also been remarkable. Over the past few decades, wind turbine design and efficiency have improved significantly, making wind power a more viable and cost-effective option. Larger and more efficient turbines, advanced blade designs, and improved control systems have all contributed to the increased productivity and reliability of wind farms.Furthermore, the integration of wind energy into the existing power grid has become more seamless. Grid-scale energy storage solutions, such as battery systems and pumped-storage hydroelectricity, have helped to address the intermittent nature of wind power, ensuring a more stable and reliable supply of electricity. This integration has made wind energy a more attractive and viable option for utilities and policymakers.The economic benefits of wind energy are equally compelling. As the cost of wind power generation continues to decline, it has become increasingly competitive with traditional fossil fuel-based electricity. This has led to a surge in investment and deployment of wind energy projects worldwide, creating jobs in the manufacturing, installation, and maintenance sectors.Additionally, the decentralized nature of wind energy has the potential to empower local communities and foster economic development in rural and remote areas. Wind farms can provide a steady stream of revenue for landowners and local governments through lease payments and tax revenue, further contributing to the economic well-being of these communities.However, the untapped potential of wind energy extends beyond its environmental and economic advantages. Wind power also holds the promise of enhancing energy security and reducing reliance on imported fossil fuels. By diversifying the energy mix and increasing the share of locally produced renewable energy, countries can reduce their vulnerability to global energy price fluctuations and geopolitical tensions.Despite these compelling advantages, the development of wind energy is not without its challenges. Regulatory barriers, grid integration issues, and public acceptance concerns have all posed obstacles to the widespread adoption of wind power. Overcoming these challenges will require a collaborative effort among policymakers, industry leaders, and the public.In conclusion, the wind energy sector holds immense potential for growth and transformation. As the world continues to grapple withthe urgent need for clean and sustainable energy sources, the development of wind power can play a crucial role in shaping a more sustainable and resilient energy future. By harnessing the power of the wind, we can unlock a new era of clean energy, foster economic growth, and contribute to the global fight against climate change.。

全新版⼤学进阶英语第⼆册第⼀单元答案Unit 1 Living GreenKey to ExercisesOpenerSuggested answers for reference1. There are a lot of simple things we can do to decrease energy consumption. Here are just a few examples:Use energy efficient light bulbs for our most-used lights.When we leave a room, turn off the light.Turn off our computer/laptop when we are not using it.Save water. Take quicker showers. When brushing teeth we should not leave faucet running.Use reusable cloth shopping bags that are made from plant fibers. Whenever possible, walk, bike, carpool, or use public transportation.2. Old clothes and books: Other people can reuse our unwanted clothes and books if we donate them.Old clothes can also be made into other items such as cushion covers. Old electrical equipment: Donate old electrical equipment to schools or community centers so that others can reuse them.Rechargeable batteries: Unlike regular batteries that create unnecessary waste, rechargeable batteries can be reused many times before they need to be thrown away.Jars and pots: By cleaning glass jars and small pots, we can use them as small containers to store odds and ends（零星物品）.3. Living green means reducing one’s carbon footprint, or, more generally, making as small an impact on the natural environment as possible. Yes, I have thought about it. I can take some small steps to restrict energy consumption. For example, taking shorter, cooler showers. In that way I can save energy by minimizing hot water use.Reading & InteractingI. Understanding the Text1. Text Organization2. Comprehension CheckFocusing on the main ideasAfter living in the city of Las Vegas for years, Alison Zeuschel and her family decided to move to the countryside. Their homehunting ended up in a very small town in Arizona where they purchased a house on 40 acres that was not only off the grid, but without access to any (public) utilities. Just imagine the challenges facing them, such as generating their own power and hauling their own water. However, they worked hard and succeeded in making the adjustment in a few months.In addition, they benefited a lot from living off the grid there. Most important of all, they came to know the importance of conservation and learned how to conserve power and water and how to reuse things, etc.In other words they learned how to live green.Digging into detail1. Her daughter wanted a horse. Her husband wanted property. Her sonwanted a dirt bike. The writer herself wanted her family to be moreself-sufficient.2. The property was off the grid. It was actually not connected to anyutilities — power, water or a sewer system.3. They generated electricity by wind and solar power, and stored itin 16 golf cart batteries. Water had to be hauled in from a nearby town and stored in two tanks located on the property.4. In her view, one of the greatest benefits was teaching her childrenthe importance of conservation.5. Other changes included reducing the amount of trash by recyclingand composting, growing their own organic vegetables and reusing things that they would normally toss away. Understanding difficult sentences1. A2. B3. B4. A5. BII. Focusing on Language in Context1. Key Words & Expressions1. Jack has no interest whatsoever in pursuing an acting career. Heloves writing and directing.2. The idea was to have users upload their medical records, so thatthey could be available at any time.3. Traffic jams often build up when drivers slow down to see whathappened in a crash.4. A native New Yorker, Ben is familiar with the city, its neighborhoods,and all he has connections with.5. You may have already seen your dream house. Before you put in anoffer, you can do a few more things to ensure you purchase the right property for the right price.6. Buying organic fruit and vegetables costs more, and for manyshoppers, the benefits hardly seem worth the extra expense.7. Self-sufficient living is the practice of providing for your ownneeds without outside aid or resources.8. In the interview, the writer was asked how he set about writing anovel based on a dream he once had.9. Are you thinking of becoming an insurance sales agent Take this quizto find out if this is the right career choice for you.10. The rent for the apartment is reasonable; besides, the utilitiesare included, which means you don’t have to pay anything for gas, electricity and water.11. A central heating and cooling system produces warm or cool air inone central area and distributes it throughout the building.12. We were deeply shocked and saddened when we learned of the suddendeath of our newly retired professor.13. If you know the ins and outs of something, you know all the detailsabout it and understand how it works.14. It’s long been proven that we can accomplish any project if we breakit up into small pieces and do the project one piece at a time.1. consist of2. tossed3. overall4. hauling5. went out6. in use1. If you’re in business long enough, it’s inevitable you will meetwith/face/encounter setbacks.2. Hydroelectric power plants generate electricity in a much cleanerway than coal-fired ones.3. Knowing the proper way to do laundry will help you avoid shrinkingyour sweaters and dyeing your white socks pink.4. We really appreciate the invitation to your party, but my elderlymother lives with us and we don’t like to leave her alone in the evenings.5. The hotel is OK but could make some adjustments to live up to its5-star rating.6. Most of us take electricity for granted. But do you know that aboutbillion people in this world have no access to electrical power2. Usage1. He spoke to her looking away, as though to avoid meeting her eyes.2. I hope to arrive in Hangzhou at 2:20 pm to catch the 3:10 train to Ningbo.3. Maria refused to attend a party to which Lucia was also invited.4. You may want to consider going on strike if you think you are paidunfair wages.5. I remember feeling really happy when I was told they had found ahouse that could meet our needs.6. If I fail to pass the exam on the first attempt, can I take the exam again7. The hotel and its staff are great. We really enjoyed staying thereduring our trip to Nanjing.8. It is not only your health that will improve if you give up smoking,but also the health of your family.9. Few of my friends could resist playing this computer game.10. Please remember to pay back the money to Mary the moment you receiveyour salary next month.3. Sentence Patterns1. It was the day before yesterday that they set out. / It was theythat set out the day before yesterday.2. It was by the roadside that I found the lost wallet. / It was Ithat/who found the lost wallet by the roadside. /It was the lost wallet that I found by the roadside.3. It was not until he got everything ready for the experiment thatXiao Wang left the lab.1. It took my parents half an hour to finally find their way back tothe hotel. / It took half an hour for my parents to finally find their way back to the hotel.2. It took us almost two hours to work out this difficult math problem./ It took almost two hours for us to work out this difficult math problem.3. It will take us more than three months to accomplish this art project./ It will take more than three months for us to accomplish this art project.4. Comprehensive PracticeClozeIf you want to know all the ins and outs of living green, then you should visit Backsbottom Farm. It is run by Rod and Jane, who have tried to be as self-sufficient as possible. They use a horse to haul the logs they cut from their woods. The fields are nourished by organic waste from the horse and their other animals rather than chemicals. They rely on a windmill to generate their electricity and when the wind slows down the lights go out and they have to set about looking for the candles.Jane, who was brought up in a home where constant electric power was taken for granted, admits it was hard to make the adjustment when they first arrived at the farm, but adds that overall they really appreciatetheir new way of life.Translation1. Jack is so diligent a student that he never goes anywhere withouta book.2. This is an outline of my paper; any of your suggestions will be trulyappreciated.3. Whether you’re buying or renting, you’ll need to be fully awarewhat kind of property best suits you and your lifestyle.4. It is dangerous to ride a bicycle on an icy road, so we have to usethe brake to slow it down.5. If we put all our energy and effort into this project, we willdefinitely accomplish it in a few more months.6. I am thinking about moving to a three-bedroom house located nearthe town center. In addition, it is within walking distance to the train station.7. A lot of the things we take for granted as trash, such as newspapers,magazines, old computers and cellphones, can actually be recycled or reused in one way or another.8. — What questions can I ask when inquiring about a job— You may ask if the position is still available and how long you have to wait before getting to know if you will be given an interview.Reading & ComprehendingReading 11. Comprehension Check for Reading 11. F2. T3. F4. T5. F6. F7. T8. T9. T 10. F2. Translation1. 在⼀个国际⼤都市（澳⼤利亚的悉尼）的郊区，有五周时间尝试⽆车的⽣活⽅式，有机会践⾏我们有关可持续发展和健康的价值观，这令我们激动不已。

The Future of Wind EnergyWind energy has been gaining traction as a viable alternative to traditional fossil fuels in recent years. With advancements in technology and increasing concern for climate change, the future of wind energy looks promising.One of the key advantages of wind energy is its renewable nature. Unlike fossil fuels, which are finite resources that contribute to greenhouse gas emissions, wind energy harnesses the power of the wind to generate electricity. This means that as long as the wind continues to blow, we can continue to produce clean, renewable energy without depleting the earth's resources.In addition to being renewable, wind energy is also clean. Unlike coal or natural gas power plants, which emit harmful pollutants into the atmosphere, wind turbines produce no greenhouse gas emissions or air pollutants while generating electricity. This makes wind energy a more environmentally friendly option for power generation, helping to reduce our carbon footprint and combat climate change.Another advantage of wind energy is its cost-effectiveness. While the initial investment in wind turbines and infrastructure may be significant, the cost of producing electricity from wind is relatively low once the turbines are in place. This can lead to long-term savings for consumers and utilities, making wind energy an attractive option for energy generation.As technology continues to advance, the efficiency and effectiveness of wind energy are expected to improve even further. Innovations in turbine design, materials, and production techniques are constantly being developed to optimize the performance of wind turbines and make them more reliable and cost-effective. This constant innovation will help drive down the cost of wind energy and make it an even more competitive option for power generation.The future of wind energy also holds promise for job creation and economic growth. The wind energy industry already employs thousands of people in manufacturing,installation, maintenance, and other sectors. As the demand for wind energy continues to grow, so too will the need for skilled workers in these areas. This can help stimulate local economies and create new opportunities for job seekers in communities around the world.In conclusion, the future of wind energy looks bright. With its renewable nature, environmental benefits, cost-effectiveness, and potential for job creation, wind energy is poised to play a significant role in the transition to a more sustainable energy future. As technology continues to improve and investments in wind energy increase, we can expect to see even greater utilization of this clean and reliable energy source in the years to come.。

风能电能英文作文英文：Wind energy and electric energy are two important forms of renewable energy. Wind energy is generated by wind turbines that convert the kinetic energy of the wind into electrical energy. Electric energy, on the other hand, is generated by power plants that convert various forms of energy, such as nuclear energy, fossil fuels, or renewable sources, into electrical energy.Wind energy has many advantages. It is clean, renewable, and does not produce any harmful emissions. It is also abundant and widely available, especially in coastal areas and open fields. Wind turbines can be installed on land or offshore, making it a versatile source of energy.However, wind energy also has some limitations. Wind turbines require a certain wind speed to generate electricity, and they can be noisy and visually intrusive.They also have a limited capacity and cannot generate electricity continuously.Electric energy, on the other hand, has a higher capacity and can generate electricity continuously. It can also be produced from a variety of sources, including renewable sources such as wind, solar, and hydroelectric power. Electric energy is also more efficient than other forms of energy, such as fossil fuels, and produces fewer emissions.However, electric energy also has some drawbacks. It requires a lot of infrastructure, including power plants, transmission lines, and distribution networks. It can also be expensive to produce and distribute, especially if it is generated from non-renewable sources.In conclusion, both wind energy and electric energy have their advantages and disadvantages. While wind energy is clean and renewable, it has limitations in terms of capacity and reliability. Electric energy, on the other hand, has a higher capacity and can be produced from avariety of sources, but it requires a lot of infrastructure and can be expensive.中文：风能和电能是两种重要的可再生能源形式。

（2011届）本科毕业设计（论文）外文翻译原文：THE NEW ENERGY ECONOMYEveryone agrees it's time, but the obstacles go well beyond matters of technology. Why real change will take nothing less than a new American revolutionTo describe what's needed to wean the country off fossil fuels, people often use the word transition. But transition is too smooth. It suggests steadiness, even inevitability, as if the endpoint is predetermined.The outcome of the tremendous push that's now underway to change how the United States and other countries obtain and consume energy is anything but predetermined. There are no definite answers to questions about the role one source of energy or another will play 15 or 20 years from now, no clear sense about the type of fuel (if any) people will put in their cars, no consensus on how quickly any of this can happen or at what cost.Nor is the change likely to be smooth and quiet. Instead, it will probably be disruptive, breaking down existing ways of thinking and acting. Not that disruption is bad: Joseph Schumpeter, the famous Austro-Hungarian economist, once spoke of "creative destruction," whereby new technologies and ideas replace old ones, which themselves are overthrown by newer, more progressive ones.Already, 2009 has been a year of visions, of prophecies. President Barack Obama's inaugural address offered one such vision: doubling alternative energy production in the next three years, updating and expanding the nation's energy infrastructure, saving billions of dollars in energy costs through improved energy efficiency. Think tanks, businesses, industry groups, and environmentalists have laid out their own plans, some more aggressive and some less so.The sheer number of these plans, not to mention the interest percolating up from nearly all corners of American life, suggests, as Energy Secretary Steven Chu puts it, that "the landscape is changing."Clean energy is, of course, a narrative that has been slowly developing in the UnitedStates over the past four decades or so, at least since President Jimmy Carter's administration. In the past, its visibility and its urgency have ebbed and flowed with the price of oil. Today, however, it's not just the wild fluctuation in oil prices that is driving the discussion. There is the economic crisis. There is the burgeoning climate crisis, with its implicit call for global cooperation. And there are fresh concerns about national security in an age of emboldened oil cartels and nuclear ambitions. Addressing each of these priorities raises its own set of questions. At the moment, there is no consensus on how aggressively the United States should reduce greenhouse gas emissions over the few next decades or, more broadly still, the proper role of fossil fuels and renewable energy.Meanw hile, almost every potential contributor to a “green energy economy"--wind and solar power, befouls, nuclear power, energy efficiency--faces hurdles well beyond the technology of each system. Regulatory policies or economic issues stand in the way of massive, quick deployment of any of these.And so, today, a new mentality is emerging among almost all the major energy players, from wind developers in the Dakotas to coal-plant operators in North Carolina: Energy issues can no longer be treated as piecemeal policy items left up to states and hodgepodge federal legislation to decide but instead must be addressed nationally, in a sweeping manner.Want the country running on flex-fuel vehicles? "It's just a few hundred dollars more per vehicles," says retired Gen. Wesley Clark, the 2004 presidential candidate and now cochairman of Growth Energy, a group representing several of the nation's largest ethanol producers. "What would encourage an automobile manufacturer to believe he should do it would be a government policy that says we are moving in that direction."Want more wind power? "The critical thing we are talking about here is national policy and the signals it sends to people," says Denise Bode, CEO of the American Wind Energy Association. "There is tremendous demand for wind power, but there is not enough transmission."The idea that a nation should have a clear-cut national energy policy sounds obvious enough. In the United States, however, the truth is that energy has not always beenconsidered a national issue, and in some ways it still isn't.Nowhere is this more obvious than with the transmission grid, a sprawling jumble of wires and mechanical connections dating back 50, 80, even 100 years in some places. Today, the grid is divided into more than 140 "balancing areas" to help manage the distribution of power. But some are so localized that they can't communicate with their next-door neighbors. As a result, extra power in one region is often wasted rather than being sent to a place that needs it.So if wind power, solar power, and plug-in electric vehicles are to be big players in the country's energy future, as many hope, this antiquated system for delivering electricity will have to change. The grid must be retooled, and new high-capacity power lines are needed to carry wind-generated electricity from the Midwest to the East and West coasts. To get those high-power lines approved, Bode and other advocates say, the federal government needs more authority to override nasty squabbles between states, environmentalists, and other interest groups that have typically stalled such efforts. The federal government, the thinking goes, already has the authority to build natural gas pipelines across state lines, and electricity should be no different. That sentiment seems to be gaining ground even among regulators who once opposed it, although there are many issues still to be worked out. As Chu says, "If we just take the view that we are going to cram something down someone's throat, this is not a constructive way of doing business" (interview, Page 32). Infrastructure is only one part of the battle to make national energy problems a national issue. Another is technology. Even though wind power technology is relatively mature--it was the country's largest provider of clean electricity last year--most other renewable sources still need work. Improvements to photovoltaic cells could reduce solar power costs significantly. New drilling technologies could help geothermal spread across a larger geographic range. Advancements in befouls, in particular to the enzymes needed to break down grasses and woods to produce ethanol, would have a major impact. Meanwhile, fossil fuels face their own technological challenges. If coal is to stay around for a while, it'll most likely be because of still-developing methods to capture carbon dioxide emissions before they enter the atmosphere.Scientific breakthroughs don't come cheap. The economic stimulus package set aside $21.5 billion for scientific research, signaling that Washington is taking a much more active role in basic energy issues after years of declining budgets at national labs. But this is just the groundwork. The most powerful force to remake the energy America uses could be government policies: climate change legislation, which would set a price on carbon dioxide emissions, and a national renewable-electricity standard, which would require the United States to get a certain portion of its electricity from renewable energy. Both rules could have far-reaching impacts, forcing industries to massively reconsider their operations, giving financial investor’s confidence to pump money into wind farms, solar fields, and other industries, and convincing the coal industry that it's worth investing billions in technology to reduce emissions.The consequences of climate change legislation, in fact, are expected to be so great that companies typically opposed to government regulation are asking Congress to go ahead and act just so that they can have some certainty about where to put their money.What Washington won't do--not in theory, anyway--is pick specific winners. "The market will decide what the mix will be," says Matt Rogers, a former director at McKinsey & Co. and now one of Chu's top advisers. "It will be interesting to see what the market brings forward." Of course, in reality, Congress's record is one of subsidizing some industries but not others. Even within the befoul world, corn-based ethanol is heavily supported, but some others, such as befoul made from algae, receive almost no backing.In this new era of national energy, one of the primary questions facing the country is that of timing. When should things happen? And how soon can they occur? "Broadly, what scares me is that we want to do this in an incremental fashion. We want this to come across as painlessly as possible," say Rich Wells, vice president of energy at Dow Chemical. "We need a breakthrough mentality."It has become a cliché to say that there is no "silver bullet" for the nation's energy and climate problems. Most experts prefer to think about energy solutions as a collection of options to be deployed in tandem. Perhaps the most widely quoted example is the "wedge model," developed by Princeton University professors Stephen Pocola andRobert Soochow in 2004. It outlined 15 wedges, each one representing a way to significantly reduce greenhouse gas emissions over the next 50 years. Among them: raising the fuel economy of 2 billion cars from 30 mpg to 60 mpg and doubling nuclear capacity worldwide.Only some of these, of course, are realistic in the shorter term. "If you're only going to do one, the top one is always energy efficiency," says Dow's Wells. "It is for the most part the easiest, cheapest fuel out there." Amory Loins, chief scientist at the nonprofit Rocky Mountain Institute, agrees, saying that energy savings from highly fuel-efficient cars would be equivalent to "finding a Saudi Arabia under Detroit." Perhaps the biggest barrier for buildings has been the upfront cost of doing retrofits, with the need to convince people that the costs can be quickly recouped by lower energy bills. The stimulus package is taking a stab at this, setting aside $5 billion for home weatherization.Meanwhile, everyone else is jockeying for position. The befoul industry wants Congress to lift the cap on how much ethanol can be blended into gasoline. The nuclear industry is asking Congress to cough up billions to insure new nuclear power plants; wind and solar industries are asking for transmission superhighways. Detroit wants more in government bailout money. And coal wants money to research carbon capture technology. The great energy nationalization is here.译文：新能源经济每个国家都希望开发新能晕，但局限于开发的障碍以及技术问题。

wind energy作文Title: The Rising Potential of Wind EnergyIn today's world, the need for sustainable and renewable energy sources has become paramount. Among the various renewable energy options, wind energy stands out as a promising alternative to fossil fuels. It offers a clean, efficient, and environmentally friendly way to generate electricity, reducing our dependence on finite and polluting resources.Wind energy harnesses the power of the wind, converting it into mechanical energy and then into electricity. Giant turbines, known as windmills or wind turbines, are strategically placed in areas with strong and consistent wind patterns. These turbines have blades that rotate when the wind blows, driving a generator to produce electricity.The advantages of wind energy are numerous. Firstly, it is a virtually inexhaustible resource. Unlike fossil fuels, which are finite and diminishing, wind is constantly present and renewable. Secondly, wind energy generates no harmful emissions during its operation, making it a clean and green source of power. This helps mitigate the effects of climate change and air pollution caused by the burning of fossil fuels.Moreover, wind energy has the potential to create jobs and economic growth. The installation, maintenance, and operation of wind turbines require skilled workers, leading to job creation in both rural and urban areas. Additionally, the development of wind energy projects often attracts investment, which can stimulate local economies.Despite these significant advantages, there are some challenges associated with wind energy. One of the main challenges is the intermittency of the wind. Since wind speeds vary depending on weather conditions and seasons, it can be challenging to predict and stabilize electricity generation from wind turbines. However, advancements in technology, such as the use of larger turbines and more efficient energy storage systems, are helping to overcome these challenges.In conclusion, wind energy represents a viable and sustainable alternative to fossil fuels. Its potential is vast, and with continued investment in research and technology, it can play a significant role in meeting our energy needs while protecting the environment. As we move towards a more sustainable future, wind energy will be a crucial component in our energy mix.。

On some of the design aspects of wind energy conversion systemsAbstractIn the overall process of utilizing wind power, two essential components of technical data, i.e. one related to the engineering or performance characteristics of commercially available wind turbine generators, and the other related to the availability of wind resources ,are need .The performance of wind energy conversion systems(WECs) depends upon subsystems like wind turbine (aaerodynamic),gears(mechanical), and generator (electrical), The availability of wind resources is governed by the climatic conditions of the region ,for which the wind survey is extremely important to exploit wind energy .In this paper, design aspects, such as factor affecting wind power, siting requirements for WECs, problems related with grid connections, classification of wind electric generation schemes, criteria for selection of equipment for WECs, choice of generators, three basic design philosophies , main considerations in wind turbine design ,choice between two and three blade rotors, weight and size considerations and environmental aspects related with WECs have been presented.1. IntroductionWind powered systems have widely used since the tenth century for water pumping, grinding and other low power application. There were several early attempts to build large scale wind powered systems to generate electricity. In 1931,the Russians built a large windmill with a 100 ft(30.5 m) diameter blade, but it had a very low conversion efficiency and was abandoned. In 1945,a Vermount utility built a large wind powered generator to produce electricity. This system costed $1.25 million and had an electrical power output of 1.25 MW. This unit lasted for 23 days before one of the blades failed due to fatigue, and the project was abandoned.The National Aeronautics and Space Administration (NASA), in conjunction with the Energy Research and Development Administration (ERDA), has built andtested a large number of large wind powered generators .The first machine was a100KW unit built at Sandusky, Ohio, for around a million dollars. A number of other machines with power up to 2.5 MW and rotor diameter up to 350 ft(107m) have been constructed. During the 1980s, it became popular to invest money in wind systems because of the tax benefits. Consequently, a number of wind farms were built, particularly in the mountain passes of California. In 1985 ,about half of the world’s wind generated electricity was produced in the Altamount Passe area of California. This area has 6700 turbines with a total rated capacity of 630 MW. Among the renewable sources off energy available today for generation of electrical power, wind energy stands foremost because of the relatively low capital cost involved and the short gestation period required. The world has obtained the installed wind capacity of 13400MW by the end of 1992.The design and successful operation of large scale wind powered generators face a number of formidable problems. If the system is designed to produce a.c power, a constant angular velocity and force problems. Unfortunately, the wind velocity is neither constant in magnitude or direction nor is it constant from the top to bottom of a large rotor. This imposes severe cyclic loads on the turbine blades, creating fatigue problems. This problem is compounded if a downwind rotor system is used because the shadow of the support tower unloads the blade. This effect also produces a noticeable noise, which can be objectionable.The available wind resource is governed by the climatology of the region concerned and has a large variability from one location to the other and also from season to season at any fixed location. A lot of development has taken place in the design of wind energy conversion systems. Modern wind turbines are highly sophisticated machines built, on the aerodynamic principles developed from the aerospace industry, incorporating advanced materials and electronics and are designed to deliver energy across a wide range of speeds. In this paper, WECs related aspects, such as factors affecting wind power, siting requirements for WECs, criteria for selection of equipment for WECs, choice of generators, three basic design philosophies, main considerations in wind turbine design, choice between two and three blade rotors, weight and size considerations and environmental aspects related with WECs have been presented.2. Factors affecting wind powerOne of the most important tools in working with the wind, whether designing a wind turbine or using one, is the firm understanding of the factors affecting the wind power. Following are the important factors that must be considered:2.1. Wind statisticsWind is a highly variable power source, and there are several methods of characterizing this variability. The most common method is the power duration curve. This is a good concept but is not easily used to select Vc and Vr for a given wind site, which is an important design requirement. Another method is to use a statistical representation, particularly a Weibull function.2.2. Load factorThere are at least two major objectives in wind turbine design. One is to maximize the average power output. The other is to meet the necessary load (which is the ratio of average electrical power to the rated electrical power) requirement of the load. Load factor is not of major concern if the wind electric generator (WEG) is acting as a fuel saver on the electric network. But if the generator is pumping irrigation water in asynchronous mode, for example, the load factor is very important.2.3. Seasonal and diurnal variation of wind powerSeasonal and diurnal variations have significant effects in wind. Load duration data are required to judge the appropriate effects. Diurnal variation is less with increased height. Average power may vary from about 80% of the long term annual average power in the early morning hour to about 120% of the long term average power in the early afternoon hours.2.4. Variation with timeFor most applications of wind power, it is more important to know about the continuity of supply than the total amount of energy available in a year. In practice, when the wind blows strongly, e.g. more than 12 m/s, there is no shortage if power, and often, the generated power has to be dumped. Difficulties appear, however, ifthere are extended periods of light or zero winds. A rule of thumb for electricity generation is that sites with average wind speed less than 5 m/s will have unacceptably long periods without generation, and the sites of average 8 m/s or above will be considered very good. In all the cases it will be necessary to match carefully the machine characteristic to the local wind regime to give the type of supply required.3. Siting requirements for WECsIn addition to adequate availability of wind resources (a minimum of 18 km/h or 5 km/h wind speed ) the following factors have to be considered while locating a WEG :a. availability of land,b. availability of power grid (for a grid connected system),c. accessibility of site,d. terrain and soil,f. frequency of lightning strokes.Once the wind resource at a particular site has been established, the next factor to be considered is the availability of land. The area of land required depends upon the size of wind farm. The optimum spacing in a row is 8-12 times the rotor diameter in the wind directions and 1.5-3 times the rotor diameter in cross wind directions. As a rule of thumb, 10 ha/MW can be taken as the land requirement of wind farms, including infrastructure. In order to optimize the power output from a given site, additional information is needed, such as wind rose, wind speeds, vegetation, topography, ground roughness etc., besides the configuration of a set of wind turbines, which can be altered for reaching best array efficiencies and highest generation. Factors such as convenient access to the wind farm site, load bearing capacity of the soil, frequency of cyclones, earthquakes etc., also require consideration before siting the wind farm.4. Choice of generatorsThere are mainly the following three classes of generators:4.1. DC generatorsDC generators are relatively unusual wind/micro-hydro turbine applications because they are expensive and require regular maintenance. Nowadays, for most d.c. applications, for example, it is more common to employ an a.c. generator to generate a.c., which is then converted to d.c. with simple solid state rectifiers.4.2. Synchronous generatorThe major advantage of synchronous generator is that its reactive power characteristic can be controlled, and therefore such machines can be used to supply reactive power to other items of power systems that require reactive power. It is normal for a stand alone wind-Diesel system to have a synchronous generator, usually connected to the Diesel engine. Synchronous generators, when fitted to a wind turbine, must be controlled carefully to prevent the rotor speed accelerating through synchronous speed especially during turbulent winds. Moreover, it requires a flexible coupling in the drive train, or to mount the gearbox assembly on springs or dampers to absorb turbulence. Synchronous generators are costlier than induction generators, particularly in smaller size ranges. Synchronous generators are more prone to failures.4.3. Induction generatorsAn induction generator offers many advantages over a conventional synchronous generator as a source of isolated power supply. Reduced unit cost, ruggedness, brushless (in squirrel cage construction), reduced size, absence of separate DC source and ease of maintenance, self-protection against severe overloads and short circuits are the main advantages. Further, induction generators are loosely coupled devices, i.e. they are heavily damped and, therefore, have the ability to absorb slight changes in rotor speed, and drive train transients to some extent, can, therefore, be absorbed, whereas synchronous generators are closely coupled devices and when used in windturbines, are subjected to turbulence and require additional damping devices, such as flexible couplings in the drive train or mounting the gearbox assembly on springs and dampers. Reactive power consumption and poor voltage regulation under varying speed are the major drawbacks of the induction generators, but the development of static power converters has facilitated control of the output of voltage of the induction generator, within limits.5. Environmental aspects5.1. Audible noiseThe wind turbine is generally quiet. It poses no objectionable noise disturbance in the surrounding area. The wind turbine manufacturers generally supply the noise level data in dB versus the distance from the tower. A typical 600 kW wind turbine may produce 55 dB noise at 50 m distance from the turbine and 40 dB at a 250 m distance. This noise is, however, a steady state noise. The wind turbine makes loud noise while yawing under changing wind direction. Local noise ordinances must be satisfied before installing wind turbines.5.2. Electromagnetic interferenceAny stationary or moving structure in the proximity of a radio or TV station interferes with the signals. The wind turbine towers can cause objectionable electromagnetic interference (EMI) on the performance of the nearby transmitters or receivers.In other aspects, the visual impact of the wind farm can be of concern to some one. The breeding and feeding patterns of birds may be disturbed. They may even be injured and even killed if they collide with the blades.6. ConclusionsThe design of wind energy conversion systems is a very complex task and requires interdisciplinary skills, e.g. civil, mechanical, electrical and electronics, geography, aerospace, environmental etc. An attempt has been made to discuss theimportant design aspects of WECs. In this paper, design aspects, such as factors affecting wind power, siting requirements for WECs, problems related with grid connections, classification of wind electric generation schemes, criteria for selection of equipment for WECs, choice of generators, three basic design philosophies, main considerations and environmentally related aspects with WECs, have been critically discussed.风能转换系统方面的设计摘要要在整个过程中利用风能,需要有两个主要的技术指标，也就是说一个在市场可以买到的符合产品设计或运行特性的风力发电机，另一个是满足要求的风力资源。

给市长的环保建议的一封信的英语作文全文共3篇示例，供读者参考篇1Dear Mayor Johnson,I am writing to you as a concerned student and resident of our great city regarding the critical issue of environmental protection. As you know, we are facing unprecedented challenges from climate change, pollution, deforestation, and the unsustainable use of natural resources. These threats not only endanger the health of our planet but also jeopardize the well-being of our communities and future generations.As young people, we have a vested interest in ensuring a livable and sustainable world for ourselves and our children. It is our responsibility to take action and make our voices heard, demanding decisive measures to safeguard our environment. Through this letter, I hope to offer some constructive suggestions that I believe can make a meaningful difference in our city's environmental efforts.Firstly, I would like to emphasize the importance of promoting and investing in renewable energy sources. Ourreliance on fossil fuels is not only detrimental to the environment but also unsustainable in the long run. By transitioning to clean and renewable sources such as solar, wind, and hydroelectric power, we can significantly reduce our carbon footprint and mitigate the effects of climate change. I propose incentivizing the installation of solar panels on residential and commercial buildings, as well as exploring the potential for wind farms in suitable locations within our city limits.Secondly, we must prioritize the reduction of waste and the implementation of effective recycling programs. The accumulation of non-biodegradable waste in landfills and oceans is a significant environmental concern. By encouraging recycling and composting initiatives, we can divert a substantial portion of our waste from landfills and promote a circular economy. Additionally, I suggest implementing a ban on single-use plastics, such as straws, bags, and utensils, to minimize the production of unnecessary waste.Thirdly, we should focus on preserving and expanding our city's green spaces. Parks, urban forests, and community gardens not only provide recreational opportunities but also contribute to cleaner air, better mental health, and increased biodiversity. I propose investing in the development of new green spaces, aswell as the maintenance and protection of existing ones. Moreover, we could encourage urban agriculture initiatives, such as community gardens, to promote sustainable food production and foster a closer connection between our residents and nature.Fourthly, I believe that improving public transportation and encouraging alternative modes of transportation are crucial steps towards reducing our carbon emissions. By investing in an efficient and reliable public transit system, as well as creating bike-friendly infrastructure, we can reduce the number of vehicles on the road and lower our dependence on fossil fuels. Additionally, we could explore incentives for electric vehicle adoption and the installation of charging stations throughout the city.Lastly, and perhaps most importantly, we must prioritize environmental education and awareness campaigns. It is essential to engage and empower our citizens, particularly the younger generation, to become active participants in environmental protection efforts. I propose incorporating environmental studies into school curricula, organizing community workshops, and launching public awareness campaigns to educate residents on sustainable practices and theimportance of individual actions in combating environmental challenges.Mayor Johnson, I understand that implementing these recommendations will require significant effort, resources, and cooperation from various stakeholders. However, the urgency of addressing environmental issues cannot be overstated. We have a moral obligation to take decisive action to protect our planet and ensure a sustainable future for generations to come.I urge you to consider these suggestions and to make environmental protection a top priority in your administration's agenda. Our city has the potential to become a model of sustainability, setting an example for others to follow. Let us work together to create a greener, healthier, and more sustainable community for all.Thank you for your time and consideration.Sincerely,[Your Name]篇2Dear Mayor Johnson,I am writing to you today as a concerned student and resident of our city. The environment is an issue that weighs heavily on my mind and the minds of many of my peers. We are the generation that will inherit the consequences of the actions we take today regarding environmental protection and sustainability. I implore you to make this a top priority for our city government.One of the most pressing environmental issues we face is air pollution from vehicle emissions and industrial activities. The smog that often blankets our city is not only unsightly, but it poses serious risks to our health, especially for vulnerable groups like children, the elderly, and those with respiratory conditions. We need to take bold steps to reduce air pollution and improve air quality.Firstly, I would suggest investing in and incentivizing public transportation and other eco-friendly modes of transportation like cycling. By making it easier and more affordable for citizens to use buses, trains, and bike lanes, we can reduce the number of cars on the road and the emissions they produce. Additionally, we should explore the possibility of implementing low-emission zones or congestion charges in heavily trafficked areas to discourage unnecessary driving.Secondly, we need to work closely with local industries and businesses to reduce their carbon footprint and adopt more sustainable practices. This could involve offering tax incentives or subsidies for companies that invest in renewable energy sources, implement energy-efficient technologies, or reduce waste and emissions. We should also consider stricter regulations and penalties for businesses that fail to meet certain environmental standards.Another area of concern is waste management and recycling. Our city's landfills are quickly reaching capacity, and we are not doing enough to divert waste from these sites. We need to expand and improve our recycling programs, making them more accessible and convenient for residents. Additionally, we should explore composting initiatives and partnerships with organizations that specialize in repurposing or upcycling materials.Furthermore, we must address the issue of water conservation and quality. Climate change is leading to more frequent and severe droughts, making it essential that we use our water resources wisely. We should encourage the use of water-saving appliances and landscaping practices, and consider implementing tiered pricing structures that incentivizeconservation. Additionally, we need to invest in upgrading our water treatment facilities and infrastructure to ensure that our drinking water is clean and safe.Green spaces and urban forests are also crucial for a healthy environment and a livable city. Trees and parks not only provide recreational opportunities for residents, but they also help to combat air pollution, reduce urban heat island effects, and provide habitats for wildlife. We should prioritize the preservation and expansion of our city's green spaces, as well as planting more trees along streets and in neighborhoods.Education and community engagement are key to achieving lasting environmental change. We need to invest in environmental education programs in our schools and communities, teaching our citizens about the importance of sustainability and how they can make a difference through their daily actions. Additionally, we should encourage and support community-led initiatives, such as neighborhood clean-ups, community gardens, and environmental advocacy groups.Finally, we must lead by example as a city government. We should strive to make our municipal buildings and operations as eco-friendly as possible, using renewable energy sources, implementing waste reduction strategies, and adoptingsustainable procurement practices. By demonstrating our commitment to environmental stewardship, we can inspire our citizens and businesses to follow suit.These are just a few of the many suggestions I have for improving our city's environmental efforts. I understand that implementing these changes will require significant resources and commitment, but the long-term benefits to our health, quality of life, and the future of our planet are invaluable.As students and the future leaders of our community, we are counting on you, Mayor Johnson, to prioritize environmental protection and sustainability. We want to inherit a city that is clean, green, and thriving – a city that we can be proud to call home. Together, we can create a brighter, more sustainable future for our city and our world.Thank you for your time and consideration.Sincerely,[Your Name]篇3Dear Mayor [Name],I am writing to you as a concerned student and resident of our wonderful city. While I am tremendously grateful for all that our community has to offer, I fear that we are not doing enough to protect our environment and ensure a sustainable future for generations to come. The health of our planet and thewell-being of our citizens should be among our top priorities, and I humbly submit the following suggestions for your consideration.First and foremost, I believe we must take immediate and decisive action to reduce our city's carbon footprint and transition towards renewable energy sources. The science is clear – human activities, particularly the burning of fossil fuels, are the primary drivers of climate change, which poses an existential threat to life on Earth as we know it. Rising temperatures, sea levels, and extreme weather events are already causing immense suffering and displacement around the world, and if we fail to act now, the consequences will be catastrophic.To this end, I propose that our city establishes ambitious yet achievable goals for reducing greenhouse gas emissions, such as a commitment to achieving carbon neutrality by 2040. This could involve investing in solar, wind, and other clean energy projects, incentivizing the adoption of electric vehicles and publictransportation, and retrofitting buildings to improve energy efficiency. Additionally, we should explore the feasibility of implementing a carbon tax or cap-and-trade system to discourage pollution and encourage sustainable practices.Secondly, we must prioritize the protection and restoration of our local ecosystems and biodiversity. Healthy, diverse ecosystems not only provide invaluable services such as air and water purification, flood mitigation, and carbon sequestration, but they also contribute to our community's overall quality of life and well-being. Unfortunately, human activities such as deforestation, urbanization, and pollution have taken a significant toll on our natural environments.To address this issue, I propose that we establish new protected areas and green spaces within our city limits, and work to restore and connect existing natural habitats. This could involve planting more trees and native vegetation, creating urban gardens and community farms, and implementing policies to safeguard wetlands, waterways, and other critical ecosystems. Furthermore, we should strive to incorporate sustainable urban planning principles, such as green infrastructure and permeable surfaces, to reduce our impact on the environment.Thirdly, we must take concrete steps to reduce waste and promote a circular economy. Our current linear model of production and consumption, where resources are extracted, used, and discarded, is unsustainable and contributes significantly to pollution and environmental degradation. By embracing the principles of the circular economy, which focuses on redesigning, reusing, and recycling materials, we can dramatically reduce our environmental impact while also creating new economic opportunities.Specifically, I recommend that our city implements comprehensive recycling and composting programs, incentivizes the use of reusable and biodegradable materials, and supports local businesses and initiatives that promote repair, repurposing, and upcycling. Additionally, we should explore ways to encourage sustainable consumption habits, such as promoting sharing economies and advocating for product stewardship and extended producer responsibility.Finally, I believe that education and community engagement are crucial to the success of any environmental initiative. We must empower our citizens with the knowledge and tools to make informed, sustainable choices and foster a culture of environmental stewardship. This could involve incorporatingenvironmental education into our school curricula, organizing community clean-up events and workshops, and providing accessible information and resources on sustainable living practices.Furthermore, we should actively seek input and collaboration from various stakeholders, including businesses, community organizations, and indigenous groups, to ensure that our environmental policies and programs are inclusive, equitable, and responsive to the needs of our diverse population.I understand that implementing these suggestions will require significant resources, commitment, and political will. However, I firmly believe that the long-term benefits of protecting our environment and securing a sustainable future for our city far outweigh the initial costs and challenges. By taking bold, decisive action now, we can not only mitigate the immense risks posed by environmental degradation and climate change but also position our city as a leader in sustainability and resilience.Our generation has inherited a planet in crisis, but we also have the opportunity to be the generation that turns things around. We have the knowledge, the technology, and the collective will to create a better, more sustainable future, but wemust act urgently and decisively. As the leaders of our community, you have the power and responsibility to prioritize environmental protection and make the difficult but necessary choices to safeguard our planet for future generations.I implore you to carefully consider these suggestions and to work tirelessly towards a more sustainable and resilient city. Our children and grandchildren are counting on us to be good stewards of the Earth and to leave them a world that is not only habitable but thriving. Let us seize this opportunity and lead by example, inspiring other communities to join us in this urgent and noble cause.Thank you for your time and consideration. I look forward to your response and to working together towards a more sustainable future for our beloved city.Sincerely,[Your Name]。