VIBRATION ANALYSIS OF CYLINDRICAL THIN SHELL

Sunday 28 August 2011

GREEN ENERGY


WHAT IS GREEN ENERGY?
Green energy is energy that is produced in a manner that has less of a negative impact to the environment than energy sources like fossil fuels, which are often produced with harmful side effects. “Greener” types of energy that often come to mind are solar, wind, geothermal and hydro energy. There are several more, even including nuclear energy, that is sometimes considered a green energy source because of its lower waste output relative to energy sources such as coal or oil.

The goal of green energy is generally to create power with as little pollution as possible produced as a by-product. Every form of energy collection will result in some pollution, but those that are green are known to cause less than those that are not. Most people who advocate greener sources of energy claim that the result of worldwide use of green energy will result in the ability to preserve the planet for a longer time. Greenhouse gases, a by-product of traditional sources of energy such as fossil fuels are thought to be causing global warming, or the process of the Earth heating up at an accelerated pace.

It is not completely necessary for green energy sources to come from places like solar or wind fields, which are examples of green “power plants.” A green energy source can be a building that is designed in a way that it keeps itself cool in the daytime and heated in the night through its architectural design rather than having an air-conditioning or a heating system. The conservation of energy through architectural design becomes, itself, a green energy source.
Similarly, many sources of green energy can come directly from the area in which the energy is needed rather than from an outside source. A residence, for example, can be covered with solar panels for the purpose of collecting energy to be used for electricity. When utilized properly, surplus energy is often produced in this manner, which can be sent back through the local power grid and used at other destinations.

One of the goals of green energy technology is to take existing fossil fuel energy technology and clean it up so it is produced more cleanly. One such case is that of clean coal technology, where scientists are trying to find ways to extract energy from coal and other fossil fuels without all of the harmful side effects. The success of such these types of green energy depend upon the ability to extract harmful by-products from fossil fuels while not only being energy efficient, but by being cost efficient as well.

SUSTAINABLE ENERGY is the provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs. Sustainable energy sources are most often regarded as including all renewable energy sources, such as hydroelectricity, solar energy, wind energy, wave power, geothermal energy, bioenergy, and tidal power. It usually also includes technologies that improve energy efficiency.
DEFINITIONS
Energy efficiency and renewable energy are said to be the twin pillars of sustainable energy.[1] Some ways in which sustainable energy has been defined are:
  • "Effectively, the provision of energy such that it meets the needs of the future without compromising the ability of future generations to meet their own needs. ...Sustainable Energy has two key components: renewable energy and energy efficiency." – Renewable Energy and Efficiency Partnership (British)[2]
  • "Dynamic harmony between equitable availability of energy-intensive goods and services to all people and the preservation of the earth for future generations." And, "the solution will lie in finding sustainable energy sources and more efficient means of converting and utilizing energy." – Sustainable energy by J. W. Tester, et al, from MIT Press.
  • "Any energy generation, efficiency & conservation source where: Resources are available to enable massive scaling to become a significant portion of energy generation, long term, preferably 100 years.." – Invest, a green technology non-profit organization.[3]
  • "Energy which is replenishable within a human lifetime and causes no long-term damage to the environment." – Jamaica Sustainable Development Network[4]
This sets sustainable energy apart from other renewable energy terminology such as alternative energy and green energy, by focusing on the ability of an energy source to continue providing energy. Sustainable energy can produce some pollution of the environment, as long as it is not sufficient to prohibit heavy use of the source for an indefinite amount of time. Sustainable energy is also distinct from Low-carbon energy, which is sustainable only in the sense that it does not add to the CO2 in the atmosphere.

Green Energy is energy that can be extracted, generated, and/or consumed without any significant negative impact to the environment. The planet has a natural capability to recover which means pollution that does not go beyond that capability can still be termed green.

Green power is a subset of renewable energy and represents those renewable energy resources and technologies that provide the highest environmental benefit. The U.S. Environmental Protection Agency defines green power as electricity produced from solar, wind, geothermal, biogas, biomass, and low-impact small hydroelectric sources. Customers often buy green power for avoided environmental impacts and its greenhouse gas reduction benefits.[5]

 

RENEWABLE ENERGY TECHNOLOGIES

Main articles: Renewable energy and Renewable energy commercialization Renewable energy technologies are essential contributors to sustainable energy as they generally contribute to world energy security, reducing dependence on fossil fuel resources,[citation needed] and providing opportunities for mitigating greenhouse gases.[6] The International Energy Agency states that:
Conceptually, one can define three generations of renewables technologies, reaching back more than 100 years .

First-generation technologies emerged from the industrial revolution at the end of the 19th century and include hydropower, biomass combustion, and geothermal power and heat. Some of these technologies are still in widespread use.

Second-generation technologies include solar heating and cooling, wind power, modern forms of bioenergy, and solar photovoltaics. These are now entering markets as a result of research, development and demonstration (RD&D) investments since the 1980s. The initial investment was prompted by energy security concerns linked to the oil crises (1973 and 1979) of the 1970s but the continuing appeal of these renewables is due, at least in part, to environmental benefits. Many of the technologies reflect significant advancements in materials.

Third-generation technologies are still under development and include advanced biomass gasification, biorefinery technologies, concentrating solar thermal power, hot dry rock geothermal energy, and ocean energy. Advances in nanotechnology may also play a major role.
International Energy AgencyRENEWABLES IN GLOBAL ENERGY SUPPLY, An IEA Fact Sheet[6]

First- and second-generation technologies have entered the markets, and third-generation technologies heavily depend on long term research and development commitments, where the public sector has a role to play.[6]

A 2008 comprehensive cost-benefit analysis review of energy solutions in the context of global warming and other issues ranked wind power combined with battery electric vehicles (BEV) as the most efficient, followed by concentrated solar power, geothermal power, tidal power, photovoltaic, wave power, coal capture and storage, nuclear energy, and finally biofuels.[7]

[EDIT] FIRST-GENERATION TECHNOLOGIES

http://upload.wikimedia.org/wikipedia/commons/thumb/e/e7/West_Ford_Flat_Geothermal_Cooling_Tower.JPG/170px-West_Ford_Flat_Geothermal_Cooling_Tower.JPGOne of many power plants at The Geysers, a geothermal power field in northern California, with a total output of over 750 MW.

First-generation technologies are most competitive in locations with abundant resources. Their future use depends on the exploration of the available resource potential, particularly in developing countries, and on overcoming challenges related to the environment and social acceptance.
International Energy AgencyRENEWABLES IN GLOBAL ENERGY SUPPLY, An IEA Fact Sheet[6]

Among sources of renewable energy, hydroelectric plants have the advantages of being long-lived—many existing plants have operated for more than 100 years. Also, hydroelectric plants are clean and have few emissions. Criticisms directed at large-scale hydroelectric plants include: dislocation of people living where the reservoirs are planned, and release of significant amounts of carbon dioxide during construction and flooding of the reservoir.[8]
http://upload.wikimedia.org/wikipedia/commons/thumb/8/81/Nishidaira_Dam.jpg/220px-Nishidaira_Dam.jpg
Hydroelectric dams are one of the most widely deployed sources of sustainable energy.

However, it has been found that high emissions are associated only with shallow reservoirs in warm (tropical) locales. Generally speaking, hydroelectric plants produce much lower life-cycle emissions than other types of generation. Hydroelectric power, which underwent extensive development during growth of electrification in the 19th and 20th centuries, is experiencing resurgence of development in the 21st century. The areas of greatest hydroelectric growth are the booming economies of Asia. China is the development leader; however, other Asian nations are installing hydropower at a rapid pace. This growth is driven by much increased energy costs—especially for imported energy—and widespread desires for more domestically produced, clean, renewable, and economical generation.
http://upload.wikimedia.org/wikipedia/commons/thumb/8/81/Hydroelectric_dam.png/220px-Hydroelectric_dam.png

Hydroelectric dam in cross section
Geothermal power plants can operate 24 hours per day, providing base-load capacity, and the world potential capacity for geothermal power generation is estimated at 85 GW over the next 30 years. However, geothermal power is accessible only in limited areas of the world, including the United States, Central America, Indonesia, East Africa and the Philippines. The costs of geothermal energy have dropped substantially from the systems built in the 1970s.[6] Geothermal heat generation can be competitive in many countries producing geothermal power, or in other regions where the resource is of a lower temperature. Enhanced geothermal system (EGS) technology does not require natural convective hydrothermal resources, so it can be used in areas that were previously unsuitable for geothermal power, if the resource is very large. EGS is currently under research at the U.S. Department of Energy.

Biomass briquettes are increasingly being used in the developing world as an alternative to charcoal. The technique involves the conversion of almost any plant matter into compressed briquettes that typically have about 70% the calorific value of charcoal. There are relatively few examples of large scale briquette production. One exception is in North Kivu, in eastern Democratic Republic of Congo, where forest clearance for charcoal production is considered to be the biggest threat to Mountain Gorilla habitat. The staff of Virunga National Park have successfully trained and equipped over 3500 people to produce biomass briquettes, thereby replacing charcoal produced illegally inside the national park, and creating significant employment for people living in extreme poverty in conflict affected areas.[9]

Solar heating systems are a well known second-generation technology and generally consist of solar thermal collectors, a fluid system to move the heat from the collector to its point of usage, and a reservoir or tank for heat storage and subsequent use. The systems may be used to heat domestic hot water, swimming pool water, or for space heating.[11] The heat can also be used for industrial applications or as an energy input for other uses such as cooling equipment.[12] In many climates, a solar heating system can provide a very high percentage (50 to 75%) of domestic hot water energy. Energy received from the sun by the earth is that of electromagnetic radiation. Light ranges of visible, infrared, ultraviolet, x-rays, and radio waves received by the earth through solar energy. The highest power of radiation comes from visible light. Solar power is complicated due to changes in seasons and from day to night. Cloud cover can also add to complications of solar energy, and not all radiation from the sun reaches earth because it is absorbed and dispersed due to clouds and gases within the earth's atmospheres.[13]
In the 1980s and early 1990s, most photovoltaic modules provided remote-area power supply, but from around 1995, industry efforts have focused increasingly on developing building integrated photovoltaics and power plants for grid connected applications (see photovoltaic power stations article for details). Currently the largest photovoltaic power plant in North America is the Nellis Solar Power Plant (15 MW).[14][15] There is a proposal to build a Solar power station in Victoria, Australia, which would be the world's largest PV power station, at 154 MW.[16][17] Other large photovoltaic power stations include the Girassol solar power plant (62 MW),[18] and the Waldpolenz Solar Park (40 MW).[19]

http://bits.wikimedia.org/skins-1.17/common/images/magnify-clip.png
http://upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Solarpipe-scheme.svg/250px-Solarpipe-scheme.svg.pngSketch of a Parabolic Trough Collector
Some of the second-generation renewables, such as wind power, have high potential and have already realised relatively low production costs. At the end of 2008, worldwide wind farm capacity was 120,791 megawatts (MW), representing an increase of 28.8 percent during the year,[20] and wind power produced some 1.3% of global electricity consumption.[21] Wind power accounts for approximately 20% of electricity use in Denmark, 9% in Spain, and 7% in Germany.[22][23] However, it may be difficult to site wind turbines in some areas for aesthetic or environmental reasons, and it may be difficult to integrate wind power into electricity grids in some cases.[6]

Solar thermal power stations have been successfully operating in California commercially since the late 1980s, including the largest solar power plant of any kind, the 350 MW Solar Energy Generating Systems. Nevada Solar One is another 64MW plant which has recently opened.[24] Other parabolic trough power plants being proposed are two 50MW plants in Spain, and a 100MW plant in Israel.[25]
http://upload.wikimedia.org/wikipedia/commons/thumb/0/03/EthanolPetrol.jpg/220px-EthanolPetrol.jpgInformation on pump, California
Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18 percent of the country's automotive fuel. As a result of this, together with the exploitation of domestic deep water oil sources, Brazil, which years ago had to import a large share of the petroleum needed for domestic consumption, recently reached complete self-sufficiency in oil.[26][27][28]
Most cars on the road today in the U.S. can run on blends of up to 10% ethanol, and motor vehicle manufacturers already produce vehicles designed to run on much higher ethanol blends. Ford, DaimlerChrysler, and GM are among the automobile companies that sell “flexible-fuel” cars, trucks, and minivans that can use gasoline and ethanol blends ranging from pure gasoline up to 85% ethanol (E85). By mid-2006, there were approximately six million E85-compatible vehicles on U.S. roads.[29]

Green energy and labelling by region

European Union

Directive 2004/8/EC of the European Parliament and of the Council of 11 February 2004 on the promotion of cogeneration based on a useful heat demand in the internal energy market[58] includes the article 5 (Guarantee of origin of electricity from high-efficiency cogeneration).

Finnish electricity markets are among the most liberal of the world. Markets were partially opened for big electricity users in 1995 and for all users in 1997.[59] In 1998 the Finnish Association for Nature Conservation launched an ecolabel for electricity. The ecolabel is called EKOenergy. 10 out of 70 Finnish electricity retailers have managed to fulfill the criteria of EKOenergy. Almost 4% of the electricity in Finland was sold under the label in 2008. End users buying EKOenergy influence in profitability of different electricity production plants.[60] In 2009 25.7% of all the energy consumed in Finland was from renewable energy sources.[61] Only part of electricity produced by renewables fulfills the EKOenergy criteria.
A Green Energy Supply Certification Scheme was launched in the United Kingdom in February 2010. This implements guidelines from the Energy Regulator, Ofgem, and sets requirements on transparency, the matching of sales by renewable energy supplies, and additionality.

United States

The United States Department of Energy (DOE), the Environmental Protection Agency (EPA), and the Center for Resource Solutions (CRS)[63] recognizes the voluntary purchase of electricity from renewable energy sources (also called renewable electricity or green electricity) as green power.

The most popular way to purchase renewable energy as revealed by NREL data is through purchasing Renewable Energy Certificates (RECs). According to a Natural Marketing Institute (NMI)[65] survey 55 percent of American consumers want companies to increase their use of renewable energy.

DOE selected six companies for its 2007 Green Power Supplier Awards, including Constellation NewEnergy; 3Degrees; Sterling Planet; SunEdison; Pacific Power and Rocky Mountain Power; and Silicon Valley Power. The combined green power provided by those six winners equals more than 5 billion kilowatt-hours per year, which is enough to power nearly 465,000 average U.S. households.
The U.S. Environmental Protection Agency (USEPA) Green Power Partnership is a voluntary program that supports the organizational procurement of renewable electricity by offering expert advice, technical support, tools and resources. This can help organizations lower the transaction costs of buying renewable power, reduce carbon footprint, and communicate its leadership to key stakeholders.

Throughout the country, more than half of all U.S. electricity customers now have an option to purchase some type of green power product from a retail electricity provider. Roughly one-quarter of the nation's utilities offer green power programs to customers, and voluntary retail sales of renewable energy in the United States totaled more than 12 billion kilowatt-hours in 2006, a 40% increase over the previous year.

Clean energy investments

2010 was a record year for green energy investments. According to a report from Bloomberg New Energy Finance, nearly US $243 billion was invested in wind farms, solar power, electric cars, and other alternative technologies worldwide, representing a 30 percent increase from 2009 and nearly five times the money invested in 2004. China had $51.1 billion investment in clean energy projects in 2010, by far the largest figure for any country.
Within the emerging economies, Brazil comes second to China in terms of clean energy investments. Supported by strong energy policies, Brazil has one of the world’s highest biomass and small-hydro power capacities and is poised for significant growth in wind energy investment. The cumulative investment potential in Brazil from 2010 to 2020 is projected as $67 billion.

India is another rising clean energy leader. While India ranked the 10th in private clean energy investments among G-20 members in 2009, over the next 10 years it is expected to rise to the third position, with annual clean energy investment under current policies forecast to grow by 369 percent between 2010 and 2020.[67]
It is clear that the epicenter of growth has started to shift to the developing economies and they may lead the world in the new wave of clean energy investments.

Nuclear power

http://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/Deuterium-tritium_fusion.svg/150px-Deuterium-tritium_fusion.svg.pngThe deuterium-tritium (D-T) reaction is one of the more promising for producing fusion power.
Nuclear power has the potential to be a sustainable energy source, such as by the use of breeder reactors. However, this is often qualified with the argument that there are serious challenges that must be dealt with before it can drastically increase its role.[68]
There are potentially two sources of nuclear power. Fission is used in all current nuclear power plants. Fusion is the reaction that powers stars, including the sun, which remains impractical for use on earth with current technology, as current fusion reactors are less than 100% efficient. However, only fission with heavy elements create significant radioactive waste that is damaging to human health in the form of activated structural material, which is one of the sustainability issues. Note that Aneutronic fusion such as He3-D fusion or Boron-Proton fusion produce far less or virtually zero radioactivity but are more difficult to fuse.

Conventional fission power is sometimes referred to as sustainable, but this is controversial politically due to concerns about peak uranium, radioactive waste disposal and the risks of disaster due to accident, terrorism, or natural disaster.

 Conclusion
Future City - 12885783To make sure we have plenty of energy in the future, it's up to all of us to use energy wisely.

We must all conserve energy and use it efficiently. It's also up to those who will create the new energy technologies of the future.
All energy sources have an impact on the environment. Concerns about the greenhouse effect and global warming, air pollution, and energy security have led to increasing interest and more development in renewable energy sources such as solar, wind, geothermal, wave power and hydrogen.

But we'll need to continue to use fossil fuels and nuclear energy until new, cleaner technologies can replace them. One of you who is reading this might be another Albert Einstein or Marie Curie and find a new source of energy. Until then, it's up to all of us.
The future is ours, but we need energy to get there.

The opportunities for green marketing opened by restructuring of the electric sector may provide our best hope to enlighten the public. The amount of renewable energy capacity installed in response to green power markets is so far modest, although the total may grow in years to come. Potentially more important, we look to the substantial ability of the private sector to stimulate demand. Simply put, if the advertising industry can sell tail fins on Cadillacs, it should be able to sell Americans clean power for the sake of their children and grandchildren. We believe that the a healthy green power market will benefit from and in turn reinforce the campaign for sound environmental policy.