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− | '''Renewable energy (sources)''' or '''RES''' capture their energy from existing flows of energy, from ''on-going natural processes'', such as [[solar power|sunshine]], [[wind power|wind]], [[hydro power|flowing water]], [[biomass|biological processes]], and [[geothermal]] heat flows.
| + | <!--{{Honor_Master|honor=Renewable Energy|master=Conservation}}--> |
− | The most common definition is that renewable energy is from an energy resource that is replaced rapidly by a natural process such as power generated from the sun or from the wind.
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| + | <!-- 1. What is renewable energy? --> |
| + | Renewable energy is energy whose origins are continually and naturally replenished without human intervention. Examples of renewable energy sources include sunlight, wind, and waves. |
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− | Most renewable forms of energy, other than geothermal and [[tidal power]], ultimately come from the [[Sun]]. Some forms are stored solar energy such as [[rain]]fall and wind power which are considered short-term solar-energy storage, whereas the energy in biomass is accumulated over a period of months, as in [[straw]], or through many years as in [[wood]]. Capturing renewable energy by plants, animals and humans does not permanently deplete the resource. [[Fossil fuel]]s, while theoretically renewable on a very long time-scale, are exploited at rates that may deplete these resources in the near future (see: [[Hubbert peak]]).
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| + | <!-- 2. Why is renewable energy important? --> |
| + | As the demand for energy resources continues to climb, mankind is faced with the dilemma of depleting the earth's resources to meet the demand. With the discovery of processes designed to harness clean and renewable energy, depletion of such resources will not be an issue, since they are naturally replenished. In addition, these processes have much less of an environmental impact than conventional methods used to harness resources such as oil. |
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− | Renewable energy resources may be used directly, or used to create other more convenient forms of energy. Examples of direct use are [[solar oven]]s, geothermal heating, and [[watermill|water-]] and [[windmill]]s. Examples of indirect use which require [[energy harvesting]] are [[electricity generation]] through [[wind turbine]]s or [[photovoltaic]] cells, or production of fuels such as ethanol from biomass (see [[alcohol as a fuel]]).
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− | A parameter sometimes used in renewable energy is the [[tonne of oil equivalent]] (toe). This is equal to 10,000 [[Calorie|Mcal]] or 41,868 MJ of energy.<ref> Unit Converter [http://www.iea.org/Textbase/stats/unit.asp IEA Statistics] (URL accessed [[January 30]], [[2006]])</ref>
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| + | <!-- 3. Describe how each of the following sources is used as a renewable source of energy. Draw an illustration depicting the usage of at least 3 of these renewable sources of energy. --> |
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− | For aspects of renewable energy use in modern societies see [[Renewable energy development]]. For a general discussion, see [[future energy development]].
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| + | Wind Power is energy that has been converted from the natural movement of wind by the use of devices such as wind turbines. It is clean, largely available, and produces no greenhouse gas emissions. |
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− | == Modern sources of renewable energy == | + | <!--T:48--> |
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| + | Bioenergy is biomass energy, which is energy from organic matter. Wood, plants, even the fumes from landfills can be used as a biomass energy source. |
| + | Ethanol is a fuel made from corn, sugar cane and other sources used in auto and jet fuel. |
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− | === Wind energy === | + | <!--T:50--> |
− | {{main article|[[Wind power]]}} | + | <noinclude></translate></noinclude> |
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| + | Geothermal energy is energy that is created and stored in the earth. It can be used for heating for large areas, mineral recovery, and industrial process heating. |
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− | As the sun heats up the Earth unevenly, winds are formed. The kinetic energy in the [[wind]] can be used to run [[wind turbine]]s, some capable of producing 5 MW of power. The power output is a function of the cube of the wind speed, so such turbines generally require a wind in the range 5.5 m/s (20 km/h), and in practice relatively few land areas have significant prevailing winds. Luckily, offshore or at high altitudes, the winds are much more constant.
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| + | Hydropower is energy that is comes from falling water. Most commonly electricity from dams or run of the river generation turbines is created. Other uses are irrigation and (in pioneer times) falling water was directly harnessed with water wheels for the operation of gristmills and sawmills. |
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− | There are now many thousands of wind turbines operating in various parts of the world, with utility companies having a total capacity of over 47317 MW<ref>"<cite>Wind energy is a relatively young but rapidly expanding industry. Over the past decade, global installed capacity has increased from 2,500 megawatts (MW) in 1992 to just over 40,000 MW at the end of 2003, at an annual growth rate of near 30%.</cite>" [http://www.ewea.org/fileadmin/ewea_documents/documents/publications/WETF/Facts_Summary.pdf EWEA Excecutive summary (pdf)] (URL accessed [[January 30]], [[2006]])</ref>. Capacity in this case means maximum possible output which does not count load factor.
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| + | Ocean Energy is energy that is comes from the ocean, which can be responsible for two types of energy: mechanical energy from the tides and waves, and thermal energy from the heat of the sun. It can be used for generating electricity. |
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− | New wind farms and offshore wind parks are being planned and built all over the world. This has been the most rapidly-growing means of electricity generation at the turn of the [[21st century]] and provides a complement to large-scale base-load power stations. Most deployed turbines produce electricity about 25% of the time (load factor 25%), but some reach 35%. The load factor is generally higher in winter. It means that a 5 MW turbine can have average output of 1.7 MW in the best case.
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| + | Solar Power is light and heat that is derived from the sun and collected through solar panels. It can be used to generate electricity for a variety of useful applications. |
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− | Global winds long-term technical potential is believed to be 5 times current global energy consumption or 40 times current electricity demand. This requires 12.7% of all land area, or that land area with Class 3 or greater potential at a height of 80 meters. It assumes that the land is covered with 6 large wind turbines per square kilometer. Offshore resources experience mean wind speeds of ~90% greater than that of land, so offshore resources could contribute substantially more energy.<ref>"<cite>Offshore stations experience mean wind speeds at 80 m that are ~90% greater than over land on average.</cite> [http://www.stanford.edu/group/efmh/winds/global_winds.html Evaluation of global wind power]<br />"<cite>Overall, the researchers calculated winds at 80 meters [300 feet] traveled over the ocean at approximately 8.6 meters per second and at nearly 4.5 meters per second over land [20 and 10 miles per hour, respectively].</cite>" [http://www.ens-newswire.com/ens/may2005/2005-05-17-09.asp#anchor6 Global Wind Map Shows Best Wind Farm Locations] (URL accessed [[January 30]], [[2006]])</ref> This number could also increase with higher altitude ground based or airborne wind turbines.<ref>"<cite>High-altitude winds could provide a potentially enormous renewable energy source, and scientists like Roberts believe flying windmills could put an end to dependence on fossil fuels. At 15,000 feet, winds are strong and constant. On the ground, wind is often unreliable -- the biggest problem for ground-based wind turbines.</cite>" [http://www.wired.com/news/planet/0,2782,67121,00.html?tw=wn_tophead_2 Windmills in the Sky] (URL accessed [[January 30]], [[2006]])</ref>
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− | There is resistance to the establishment of land based wind farms owing initially to perceptions that they are noisy and contribute to "visual pollution," i.e., they are considered to be eyesores. Many people also claim that turbines kill birds, and that they in general do little for the environment.
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| + | <!-- 4. Individually or as a group, discuss some of the earliest forms of renewable energy. Are there energy forms that might have been used before sin? By Noah? By the patriarchs? --> |
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− | Others have argued that they find the turbines beautiful, that turbines out at sea are invisible to anyone on the shore, that cars or plate glass windows kill far more birds annually and that turbines are continuing to evolve.
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| + | The earliest form of renewable energy was probably the burning of biomass in the form of wood and dried animal dung. The fuel could be stored, and energy was available for immediate use, but the energy could not be kept in storage for afterwards. |
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− | Wind strengths vary and thus cannot guarantee continuous power. Some estimates suggest that 1,000MW of wind generation capacity can be relied on for just 333 MW of continuous power. While this might change as technology evolves, advocates have suggested incorporating wind power with other power sources, or the use of energy storage techniques, with this in mind. It is best used in the context of a system that has significant reserve capacity such as hydro, or reserve load, such as a desalination plant, to mitigate the economic effects of resource variability.
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| + | Some people believe that the pre-flood culture had advanced technologies. Out of place artifacts like machined balls and gold chains inside coal suggest this. Consider how much knowledge a person living hundreds of years and so close to God's perfect creation of Adam and Eve could amass and what they could create with that knowledge. The world had one language as well, and many overlapping generations, facilitating communication. |
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− | [[Wind power]] is renewable and is one of the few energy sources that contributes to [[greenhouse gas]] mitigation, because it removes energy directly from the atmosphere without producing net emissions of greenhouse gases such as [[carbon dioxide]] and [[methane]] (others greenhouse gas mitagating energy sources include [[solar thermal]] and [[ocean thermal]]).
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| + | Additional references are available from the Bible which can provide further insight into this. For example, the sun, the movement of water through rivers, etc. |
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− | === Water power === | + | <!--T:60--> |
− | {{main article|[[Water power]]}} | + | <noinclude></translate></noinclude> |
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| + | <!-- 5. Individually or as a group, show at least five important events in the history of renewable energy through:<br>a. Presentation<br>b. Video<br>c. Interactive game<br>d. Speech<br>e. Display --> |
| + | For this requirement, you will need to research the history of renewable energy, and then present your findings using one of the techniques listed in the requirement. |
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− | Energy in water can be harnessed and used, in the form of motive energy or temperature differences. Since water is about a thousand times heavier than air, even a slow flowing stream of water can yield great amounts of energy.
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| + | Prior to the development of coal in the mid 19th century, nearly all energy used was renewable. Almost without a doubt the oldest known use of renewable energy, in the form of traditional biomass to fuel fires, dates from the beginning of history. |
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− | There are many forms:
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− | * [[Hydroelectric]] energy, a term usually reserved for hydroelectric dams.
| + | Probably the second oldest usage of renewable energy is harnessing the wind in order to drive ships over water. This practice can be traced back to ships on the Nile. |
− | * [[Tidal power]], which captures energy from the tides in horizontal direction. Tides come in, raise waterlevels in a basin, and tides roll out. The water must pass through a [[turbine]] to get out of the basin.
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− | * [[Tidal stream power]], which does the same vertically, capturing the stream of water as it is pushed around the world by the tides.
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− | * [[Wave power]], which uses the energy in waves. The waves will usually make large [[pontoon]]s go up and down in the water.
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− | * [[Ocean thermal energy conversion]] (OTEC), which uses the temperature difference between the warmer surface of the ocean and the cool (or cold) lower recesses. To this end, it employs a [[heat engine | cyclic heat engine]].
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− | * [[Deep lake water cooling]], not technically an energy generation method, though it can save a lot of energy in summer. It uses submerged pipes as a [[heat sink]] for [[air conditioning|climate control systems]]. Lake-bottom water is a year-round local constant of about 4 °[[Celsius|C]].
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− | Hydroelectric power is probably not a major option for the future of energy production in the developed nations because most major sites within these nations with the potential for harnessing gravity in this way are either already being exploited or are unavailable for other reasons such as environmental considerations. However, [[micro hydro]] may be an option for small scale applications such as single farms, homes or small businesses.
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| + | The primary sources of traditional renewable energy were human labor, animal power, water power, wind, in grain crushing windmills, and firewood, a traditional biomass. A graph of energy use in the United States up until 1900 shows oil and natural gas with about the same importance in 1900 as wind and solar played in 2010. |
− | Building a dam often involves flooding large areas of land, changing habitats, and while hydroelectric energy produces essentially no carbon dioxide, recent reports have linked hydroelectric power to methane, which forms out of decaying submerged plants which grow in the dried up parts of the basis in times of drought. Methane is a potent greenhouse gas.
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− | The other methods of energy generation (and cooling) have had varying degrees of success in the field. Wave and tidal power prove hard to tap, while OTEC has not been field tested on a large scale. | + | <!--T:19--> |
| + | By 1873, concerns of running out of coal prompted experiments with using solar energy. Development of solar engines continued until the outbreak of World War I. The importance of solar energy was recognized in a 1911 Scientific American article: "in the far distant future, natural fuels having been exhausted [solar power] will remain as the only means of existence of the human race". |
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− | The general public mostly considers water power energy to be renewable. | + | <!--T:20--> |
| + | The theory of peak oil was published in 1956. In the 1970s environmentalists promoted the development of renewable energy both as a replacement for the eventual depletion of oil, as well as for an escape from dependence on oil, and the first electricity generating wind turbines appeared. Solar had long been used for heating and cooling, but solar panels were too costly to build solar farms until 1980. |
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− | ===Solar energy burns peoples hair in tradjic yatch acident=== | + | <!--T:62--> |
− | [[Image:Solar_panels_on_yacht_at_sea.jpg|thumb|right|300px|The solar panels (photovoltaic arrays) on this small yacht at sea can charge the 12 V batteries at up to 9 amperes in full, direct sunlight.]]
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− | {{main article|[[Solar power]]}}
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| + | <!-- 6. Discover the source of most reusable energy. --> |
| + | The source of most renewable energy comes from the sun. |
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− | Since most renewable energy is ultimately "solar energy" this term is slightly confusing and used in two different ways: firstly as a synonym for "renewable energies" as a whole and secondly for the energy that is directly collected from sunlight. In this section it is used in the latter category.
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− | Solar power can be used to:
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− | * generate electricity using [[solar cells]]
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− | * generate electricity using [[Solar power#Solar thermal power plants|thermal power plants]]
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− | * generate electricity using [[Solar Tower|solar towers]]
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− | * heat buildings, directly
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− | * heat buildings, through [[heat pump]]s
| + | <!-- 7. What are some commercial and industrial uses of renewable energy? --> |
− | * heat foodstuffs, through [[solar oven]]s.
| + | Renewable energy such as solar energy can be used to supply power larger communities through a solar power station. Tanks of molten salt can be used to store the energy harnessed from the sun for the purpose of generating electricity during cloud cover, or through the night. Renewable energy can also be used for agricultural purposes, providing social services, education, and health care. |
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− | Obviously the sun does not provide constant energy to any spot on the Earth, so its use is limited. Solar cells are often used to power batteries, as most other applications would require a secondary energy source, to cope with outages. Some homeowners use a solar system which sells energy to the grid during the day, and draw energy from the grid at night; this is to everyone's advantage, since power demand for air conditioning is highest during the day.
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| + | Fuel made from bio sources like corn is now a common ingredient in automotive fuel. |
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− | Problems generally associated with solar energy:
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− | <ul>
| + | Hydro electric power (electricity) is a renewable energy used everywhere the grid goes. |
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− | <li>It is not available in dark or cloudy conditions, hence producing variable voltages. | + | <!--T:66--> |
− | <li>Solar panels are expensive and energy collection is not yet optimized. | + | <noinclude></translate></noinclude> |
− | <li>The current generated is only of DC type. It must be converted to AC current before transmission. | + | {{CloseReq}} <!-- 7 --> |
− | </ul>
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| + | <!-- 8. Why have many governments invested in renewable energy sources? Be able to cite at least two examples. --> |
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− | === Geothermal energy ===
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− | {{main article|[[Geothermal energy]]}}
| + | There are positive incentives for governments to invest in renewable energy sources. |
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− | Geothermal energy ultimately comes from [[radioactive decay]] in the core of the [[Earth]], which heats the Earth from the inside out, and from the sun, which heats the surface. It can be used in three ways:
| + | ===The Overall Impact on the Planet=== <!--T:27--> |
− | * Geothermal electricity
| + | Most sources of renewable energy pose no noxious by-products (the main exception being the burning of biomass). As a result, there is less pollution, waste, and less of a threat concerning extremely destructive natural disasters. |
− | * Geothermal heating, through deep Earth pipes
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− | * Geothermal heating, through a [[heat pump]].
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− | Usually, the term 'geothermal' is reserved for thermal energy from within the Earth.
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| + | The reality of global warming has also become a considerable factor with regard to the harmful effects of carbon dioxide (CO2) on the balance of the planet’s ecosystem. The less CO2, the better of our planet would be. |
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− | Geothermal electricity is created by pumping a fluid (oil or water) into the Earth, allowing it to evaporate and using the hot gases vented from the earth's crust to run [[turbine]]s linked to [[electrical generator]]s.
| + | ===The Failure of its Technology More Minimized=== <!--T:29--> |
| + | The technology used to harness energy from renewable resources is essentially stable. As a result, insurance companies are more inclined to issue warranties for performance of panels and turbines for 20 years or more. Once these items are installed, they can be relied upon to start working straight away and not stop for years. |
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− | The geothermal energy from the core of the Earth is closer to the surface in some areas than in others. Where hot underground steam or water can be tapped and brought to the surface it may be used to generate electricity. Such [[geothermal power]] sources exist in certain geologically unstable parts of the world such as [[Iceland]], [[New Zealand]], [[United States]], [[Philippines|the Philippines]] and [[Italy]]. The two most prominent areas for this in the United States are in the [[Yellowstone National Park|Yellowstone]] basin and in northern [[California]]. [[Iceland]] produced 170 MW geothermal power and heated 86% of all houses in the year 2000 through geothermal energy. Some 8000 MW of capacity is operational in total.
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| + | <!-- 9. What are some of the issues facing the use of renewable energy? What are some of the advantages and potential disadvantages of moving away from fossil fuel energy sources to renewable energy? --> |
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− | Geothermal heat from the surface of the Earth can be used on most of the globe directly to heat and cool buildings. The temperature of the crust a few feet below the surface is buffered to a constant 7 to 14 °C (45 to 58 °F), so a liquid can be pre-heated or pre-cooled in underground pipelines, providing free cooling in the summer and, via a [[heat pump]], heating in the winter. Other direct uses are in agriculture (greenhouses), aquaculture and industry.
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− | | + | Although renewable energy has many advantages with regard to its environmental impact, there are concerns that must be considered as well. The ability to supply energy to meet the demand may pose a problem. Providing renewable energy requires designing and building equipment that will harness and extract it once found. The entire manufacturing process must be considered as well. |
− | Although geothermal sites are capable of providing heat for many decades, eventually specific locations cool down. Some interpret this as meaning a specific geothermal location can undergo depletion. Others see such an interpretation as an inaccurate usage of the word depletion because the overall supply of geothermal energy on Earth, and its source, remain nearly constant. Geothermal energy depends on local geological instability, which, by definition, is unpredictable, and might stabilise. | + | |
− | | + | The general population has grown accustomed to current resources such as oil for heating. As such, although the development of an cleaner, alternative means that present less of an environmental impact may not gain the momentum desired. Some renewable resources have not been around long and tested long enough for individuals to give up what they are comfortable with for something that may be cleaner. |
− | The present consumption of geothermal energy does not in any way threaten or diminish the quality of life for future generations, consequently, it is considered a renewable energy source.
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− | === Biomass ===
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− | {{main article|[[Biofuel]]}}
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− | Plants use [[photosynthesis]] to store solar energy in the form of [[chemical energy]]. Biofuel is any fuel that derives from biomass - recently living organisms or their metabolic byproducts, such as manure from cows. It is a renewable energy.
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− | Typically biofuel is burned to release its stored chemical energy. Research into more efficient methods of converting biofuels and other fuels into electricity utilizing fuel cells is an area of very active work.
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− | [[Biomass]], also known as biomatter, can be used directly as fuel or to produce liquid [[biofuel]]. Agriculturally produced biomass fuels, such as [[biodiesel]], [[ethanol]] and [[bagasse]] (often a by-product of [[sugar cane]] cultivation) can be burned in [[internal combustion engine]]s or [[boiler]]s.
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− | A drawback is that all biomass needs to go through some of these steps: it needs to be grown, collected, dried, fermented and burned. All of these steps require resources and an infrastructure. However, since the government passed legislation that requires the integration of 7.5 billion U.S. gallons (28,000,000 m³) of ethanol into the gasoline supply experts estimate that six million dollars of investment will be created along with 200,000 additional jobs in the United States.
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− | Biomatter energy, under the right conditions, is considered to be renewable.
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− | ==== Liquid biofuel ====
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− | Liquid biofuel is usually bioalcohol such as [[methanol]], [[ethanol]] and [[biodiesel]]. Biodiesel can be used in modern diesel vehicles with little or no modification and can be obtained from waste and crude vegetable and animal oil and fats ([[lipid]]s). A major benefit of biodiesel is lower emissions. The use of biodiesel reduces emission of carbon monoxide and other hydrocarbons by 20 to 40 percent. In some areas [[maize|corn]], [[sugarbeet]]s, cane and grasses are grown specifically to produce ethanol (also known as alcohol) a liquid which can be used in [[internal combustion engine]]s and [[fuel cells]]. Ethanol is being phased into the current energy infrastructure. E85 is a fuel composed of 85% ethanol and 15% gasoline that is currently being sold to consumers.
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− | The EU plans to add 5% [[bioethanol]] to Europe's petrol by 2010. For the UK alone the production would require 12,000 square kilometres of the country's 65,000 square kilometres of arable land assuming that no biofuels are created using waste produces from other agriculture. The [[supermarket]] chain [[Tesco]] has started adding the 5% bioethanol to the petrol it sells as of January 2006.
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− | ==== Solid biomass ====
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− | Direct use is usually in the form of combustible solids, either firewood or combustible field crops. Field crops may be grown specifically for combustion or may be used for other purposes, and the processed plant waste then used for combustion. Most sorts of biomatter, including dried manure, can actually be burnt to heat water and to drive turbines.
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− | [[Sugar cane]] residue, [[wheat]] chaff, [[maize|corn cobs]] and other plant matter can be, and is, burnt quite successfully. The process releases no net CO<sub>2</sub>.
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− | Solid biomass can also be [[gasification|gasified]], and used as described in the next section.
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− | ==== Biogas ====
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− | {{main article|[[biogas]]}}
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− | Many organic materials can release gases, due to metabolisation of organic matter by bacteria ([[fermentation]]). [[Landfills]] actually need to release this gas to prevent dangerous explosions. Animal feces releases methane under the influence of [[anaerobic bacteria]].
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− | Also, under high pressure, high temperature, [[anaerobic]] conditions many organic materials such as wood can be [[gasification|gasified]] to produce gas. This is often found to be more efficient than direct burning.
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− | The gas can then be used to generate electricity and/or heat. | |
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− | Biogas can easily be produced from current waste streams, such as: paper production, sugar production, sewage, animal waste and so forth. These various waste streams have to be slurried together and allowed to naturally ferment, producing methane gas. We just need to convert current sewage plants to biogas plants, build more locally centered smaller biogas plants and plan for the future. Biogas production has the capacity to provide us with about half of our energy needs, either burned for electrical productions or piped into current gas lines for use. It just has to be done and made a priority. Besides, when a plant has extracted all the methane it can, we are left with a better fertilizer for our farms than we started with.
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− | == Small scale energy sources ==
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− | There are many small scale energy sources that generally cannot be scaled up to industrial size. A short list:
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− | * [[piezoelectricity|Piezo electric]] crystals generate a small voltage whenever they are mechanically deformed. Vibration from [[internal combustion engine|engines]] can stimulate piezo electric crystals, as can the heels of shoes
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− | * Some watches are already powered by kinetics, in this case movement of the arm
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− | * [[Electrokinetics]] generate electricity from the kinetic energy in water that is pumped through tiny channels
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− | * Special [[antenna (electronics)|antennae]] can collect energy from stray radio waves or theoretically even light ([[Electromagnetic radiation|EM radiation]]).
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− | | |
− | == Issues ==
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− | === Aesthetics, habitat hazards and land use ===
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− | Some people dislike the aesthetics of [[wind turbines]] or bring up nature conservation issues when it comes to large solar-electric installations outside of cities. Some people try to utilize these renewable technologies in an efficient and aesthetically pleasing way: fixed solar collectors can double as noise barriers along highways, roof-tops are available already and could even be replaced totally by solar collectors, [[photovoltaic cell|amorphous photovoltaic cells]] can be used to tint windows and produce energy etc.
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− | | |
− | Some renewable energy capture systems entail unique environmental problems. For instance, wind turbines can be hazardous to flying birds, while hydroelectric dams can create barriers for migrating fish - a serious problem in the Pacific Northwest that has decimated the numbers of many salmon populations. Burning biomass and biofuels causes air pollution similar to that of burning fossil fuels, although it causes a lower greenhouse effect since the carbon placed in the atmosphere was already there before the plants were grown, rather than being "new" carbon from fossil fuels <!-- this could prolly be phrased better... -->.
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− | | |
− | Another problem with many renewables, especially biomass and biofuels, is the large amount of land required, which otherwise could be left as wilderness.
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− | | |
− | === Concentration ===
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− | Another inherent difficulty with renewables is their variable and diffuse nature (the exception being [[geothermal energy]], which is however only accessible in exceptional locations). Since renewable energy sources are providing relatively low-intensity energy, the new kinds of "power plants" needed to convert the sources into usable energy need to be distributed over large areas.
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− | | |
− | Electrical power consumption in Western countries averages about 100 watts continuously per person (i.e. about 1 MWh per year). In cloudy [[Europe]] this would require about eight square meters of [[solar panel]]s, assuming a below-average solar conversion rate of 12.5%. Systematic electrical generation requires reliable overlapping sources or some means of [[grid energy storage|storage]] on a reasonable scale ([[hydroelectricity|pumped-storage hydro system]]s, batteries, hydrogen [[fuel cell]]s, etc). So, because of current costs of such energy storage systems, a stand-alone system is only economic in rare cases, or where a connection to a public grid would be impractical.
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− | | |
− | === Proximity to demand ===
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− | The geographic diversity of resources is also significant. Some countries and regions have significantly better resources than others in particular RE sectors. Some nations have significant resources at distance from the major population centers where electricity demand exists. Exploiting such resources on a large scale is likely to require considerable investment in transmission and distribution networks as well as in the technology itself.
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− | | |
− | Rooftop photovoltaic arrays are especially attractive in that most of the power they produce is consumed in the structure on which they are mounted or in other nearby buildings.
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− | | |
− | === Availability ===
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− | One recurring criticism of renewable sources is their intermittent nature. Sunlight is only available during the day (50% of the time, on a yearly basis). Wind energy is somewhat more available, while geothermal and wave energy are continuously available, although wave intensity varies by season. A wave energy scheme installed in Australia is generating electricity with an 80% availability factor.
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− | | |
− | === Fossil fuels ===
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− | {{main article|[[Fossil fuel]]}}
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− | Renewable energy sources are fundamentally different from fossil fuel or nuclear power plants because the Sun will 'power' these 'power plants' (meaning sunlight, the wind, flowing water, etc.) for the next 4 billion years. They also do not directly produce greenhouse gases and other emissions, as fossil fuel combustion does. Most do not introduce any global new risks such as [[nuclear waste]].
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− | | |
− | Fossil fuels are not considered a renewable energy source, but are often compared and contrasted with renewables in the context of [[future energy development]].
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− | | |
− | The traditionally, though not universally, held Western (biogenic) theory postulates that fossil fuels are the altered remnants of ancient plant and animal life deposited in sedimentary rocks. They were formed millions of years ago and have rested underground, mostly dormant, since that time.
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− | | |
− | In contrast, the [[Abiogenic petroleum origin]] theory states that [[petroleum]] (or [[crude oil]]) is primarily created from non-[[biology|biological]] sources of [[hydrocarbon]]s located deep in the [[Earth]]. This view was championed by [[Fred Hoyle]] in his book ''The Unity of the Universe''.
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− | | |
− | Though it is possible to produce complex [[hydrocarbons]] artificially by using the [[Fischer-Tropsch process]], this process does not generate energy, and cannot be considered a large scale solution to the energy problem.
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− | The coal industry in the US is publicly claiming coal is renewable energy because the coal was originally biomass. However, the biomass of fossil fuels was produced on the time scale of millions of years through a series of events and it is considered to be a deposit of energy, not an energy flow. Some scientist hold the view that the formation of fossil fuels was a one-time event, made possible by unique conditions during the [[Devonian]] period, such as increased oxygen levels and huge swamps.
| + | <!--T:70--> |
− |
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− | When the term renewable was introduced (see [[Renewable energy#Defining renewable|Defining renewable]] within this article), it was a generally held belief that the Earth's sources would be depleted within some 50 years. Since then, large deposits of deep-Earth oil have been found, which has extended this timetable. Because the current rate of consumption exceeds the rate of renewal (if, indeed, there is renewal of fossil fuels), the Earth will eventually run out of fossil fuels (''see [[peak oil]]'').
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| + | <!-- 10. Individually or as a group, build, not from a kit, a device to harness some form of renewable energy. These devices may include:<br>a. Potato clock<br>b. Solar or wind powered motor<br>c. Hydropower lift<br>d. Your choice. --> |
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− | === Transmission ===
| + | <!--T:72--> |
− | If renewable and [[distributed generation]] were to become widespread, [[electric power transmission]] and [[electricity distribution]] systems might no longer be the main distributors of electrical energy but would operate to balance the electricity needs of local communities. Those with surplus energy would sell to areas needing "top ups". That is, network operation would require a shift from 'passive management' - where generators are hooked up and the system is operated to get electricity 'downstream' to the consumer - to 'active management', wherein generators are spread across a network and inputs and outputs need to be constantly monitored to ensure proper balancing occurs within the system. Some Governments and regulators are moving to address this, though much remains to be done. One potential solution is the increased use of active management of electricity transmission and distribution networks. This will require significant changes in the way that such networks are operated.
| + | Note: Internet search engines provide tons of information when you type one of the sources of renewable power and “science experiment.” Thus for hydropower you would search for “hydropower science experiment.” |
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− | However, on a small scale, use of renewable energy that can often be produced "on the spot" lowers the requirements [[electricity distribution]] systems have to fulfill. Current systems, while rarely economically efficient, have proven an average household with a solar panel array and energy storage system of the right size needs electricity from outside sources for only a few hours every week. Hence, advocates of renewable energy believe electricity distribution systems will become smaller and easier to manage, rather than the opposite.
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| + | <!-- 11. Brainstorm a list of at least four Biblical texts/stories that illustrate the use of renewable energy. --> |
| | | |
− | == Historical usage of renewable energy == | + | ===Wind - to move ships through the waters.=== <!--T:34--> |
− | Throughout history, various forms of renewable and non-renewable energies have been employed.
| + | {{Bible verse |
| + | |book=Jonah |
| + | |chapter=1 |
| + | |verse=4 |
| + | |version=KJV |
| + | |text= |
| + | “But the Lord sent out a great wind into the sea, and there was a mighty tempest in the sea, so that the ship was like to be broken.” |
| + | }} |
| | | |
− | *[[Wood fuel|Wood]] was the earliest manipulated energy source in human history, being used as a thermal energy source through burning, and it is still important in this context today. Burning wood was important for both [[cooking]] and providing heat, enabling human presence in cold climates. Special types of wood cooking, [[drying (food)|food dehydration]] and [[smoking (food)|smoke curing]], also enabled human societies to safely store perishable foodstuffs through the year. Eventually, it was discovered that partial combustion in the relative absence of oxygen could produce [[charcoal]], which provided a hotter and more compact and portable energy source. However, this was not a more efficient energy source, because it required a large input in wood to create the charcoal.
| + | ===In Job, Satan used a wind power for evil.=== <!--T:35--> |
− | *[[Animal power]] for vehicles and mechanical devices was originally produced through [[animal traction]]. Animals such as horses and oxen not only provided transportation but also powered mills. Animals are still extensively in use in many parts of the world for these purposes.
| + | {{Bible verse |
− | *[[Human power]] for vehicles, mechanical devices and individual non-machine-aided transportation has been employed throughout human history. Slaves have been used for powering boats and powering construction machinery such as that used to build the Egypian pyramids. Today, slaves have largely been replaced by other sources of power to the degree that the average American accesses the same amount of power that otherwise would require 50 slaves. One of the largest uses of human power today is bicycling.
| + | |book=Job |
− | *[[Water power]] eventually supplanted animal power for mills, wherever the power of falling water in rivers was exploitable . Water power through [[hydroelectricity]] continues to be the least expensive method of storing and generating dispatchable energy throughout the world. Historically as well as presently, hydroelectricity provides more renewable energy than any other renewable source.
| + | |chapter=1 |
− | *[[Animal oil]], especially [[whale oil]] was long burned as an oil for light.
| + | |verse=19 |
− | *[[Wind power]] has been used for several hundred years. It was originally used via large sail-blade [[windmill]]s with slow-moving blades, such as those seen in the [[Netherlands]] and mentioned in [[Don Quixote]]. These large mills usually either pumped water or powered small mills. Newer windmills featured smaller, faster-turning, more compact units with more blades, such as those seen throughout the [[Great Plains]]. These were mostly used for pumping water from wells. Recent years have seen the rapid development of wind generation farms by mainstream power companies, using a new generation of large, high wind turbines with two or three immense and relatively slow-moving blades. Today, wind power is the fastest growing energy source in the world.
| + | |version=KJV |
− | *[[Solar power]] as a direct energy source has been not been captured by mechanical systems until recent human history, but was captured as an energy source through architecture in certain societies for many centuries. Not until the twentieth century was direct solar input extensively explored via more carefully planned architecture (passive solar) or via heat capture in mechanical systems (active solar) or electrical conversion (photovoltaic). Increasingly today the sun is harnessed for heat and electricity.
| + | |text= |
− | *Attempts to harness the power of [[Wave power|ocean waves]] appears in drawings and patents back to the 19th century. Modern attempts to capture wave power began in the 1970's by Professor Steven Salter who started the Wave Energy Group at the University of Edinburgh in Scotland. There are several pilot plants generating power into the grid, and many new and curious designs are in various stages of development and testing.
| + | “And, behold, there came a great wind from the wilderness, and smote the four corners of the house, and it fell upon the young men, and they are dead; and I only am escaped alone to tell thee.” |
| + | }} |
| | | |
− | == See also == | + | ===Biomass - from firewood=== <!--T:36--> |
| + | {{Bible verse |
| + | |book=Leviticus |
| + | |chapter=1 |
| + | |verse=6-8 |
| + | |version=KJV |
| + | |text= |
| + | “And the sons of Aaron the priest shall put fire upon the altar, and lay the wood in order upon the fire: And the priests, Aaron's sons, shall lay the parts, the head, and the fat, in order upon the wood that is on the fire which is upon the altar.” |
| + | }} |
| | | |
− | * [[Nuclear power phase-out]]
| + | <!--T:37--> |
− | * [[Renewable energy development]]
| + | {{Bible verse |
− | * [[Renewable energy links]]
| + | |book=1 Kings |
− | * [[Soft energy path]]
| + | |chapter=17 |
− | * [[Sustainable energy]]
| + | |verse=10-12 |
− | * [[Wind power]]
| + | |version=KJV |
− | * [[Tidal power]]
| + | |text= |
| + | “And when he came to the gate of the city, indeed a widow was there gathering sticks. And he called to her and said, “Please bring me a little water in a cup, that I may drink.” And as she was going to get it, he called to her and said, “Please bring me a morsel of bread in your hand.” |
| | | |
− | == External links ==
| + | <!--T:38--> |
− | * [http://www.world-council-for-renewable-energy.org/ World Coucil for Renewable Energy WCRE]
| + | So she said, “As the Lord your God lives, I do not have bread, only a handful of flour in a bin, and a little oil in a jar; and see, I am gathering a couple of sticks that I may go in and prepare it for myself and my son, that we may eat it, and die.” |
− | * [http://eosweb.larc.nasa.gov/sse Surface meteorology and Solar Energy - a renewable energy resource for data and images]
| + | }} |
− | * [http://www.greenmountain.com Green Mountain Energy]
| |
− | * [http://www.renewableenergyaccess.com Renewable Energy News from around the world]
| |
− | * [http://www.futurecrisis.com/alternative-energy-plans.php Renewable Energy Projects and Daily News]
| |
− | * [http://energia.co.nr/ Renewable Energy Projects (site in spanish)]
| |
− | * [http://www.cus.net/ Renewable Energy]
| |
− | * [http://groups.yahoo.com/group/worldoilboycott World Oil Boycott Grassroots Organization]
| |
− | * [http://www.greenprogress.com/alternative_energy.php Green Progress - alternative energy news]
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− | * [http://www.solardrome.com SolarDrome Renewable Energy from Around the Web]
| |
− | * [http://www.greenfuelonline.com/enterprise4.htm Technology turns greenhouse gas emissions to clean air biofuels]
| |
− | * [http://www.ief-energy.org/ International Energy Foundation]
| |
− | * [http://www.inboxrobot.com/news/AlternativeEnergy Alternative Energy newsletter for Research Professionals]
| |
− | * [http://www.nrel.gov/ National Renewable Energy Laboratory (American)]
| |
− | * [http://www.GenomeNewsNetwork.org/categories/index/energy.php Genome News Network (GNN) Energy News] Collection of articles about how advances in genomics is leading to advances in energy production.
| |
− | * [http://www.cat.org.uk/ Centre for Alternative Energy (European)]
| |
− | * [http://www.activistmagazine.com/index.php?option=content&task=view&id=120 Carbon Activism for Beginners].
| |
− | * [http://www.ecoresearch.net/election2004/report/sentence?s=1 Renewable Energy Media Analysis] — US Election 2004 Web Monitor
| |
− | * [http://europa.eu.int/comm/energy/intelligent/index_en.html EU Intelligent Energy], [[energy efficiency]] and [[renewables]].
| |
− | * [http://www.ademe.fr/ French Agency for the Environment and Energy Management], fields of activity : air quality, wastes, energy-efficiency and renewables, environmental management, polluted soils, transportation
| |
− | * [http://www.itdg.org/ Intermediate Technology Development Group]
| |
− | * [http://www.thehydrogenexpedition.com/ The Hydrogen Expedition] Renewable energy world record
| |
− | * [http://www.aapg.org/explorer/2002/11nov/abiogenic.cfm Abiogenic Gas Debate] On the possible abiogenic origin of fossil fuels
| |
− | * [http://wiki.greenpowered.org Green Wiki] Collective articles on renewable energy and other topics related to sustainable living
| |
− | * [http://energy.sourceguides.com/index.shtml The Source for Renewable Energy] A directory to more than 9000 renewable energy businesses worldwide
| |
− | * [http://environmental-finance.com Environmental Finance magazine]
| |
− | * [http://climatechangeaction.blogspot.com/2005/09/energy-efficiency-vs-small-scale.html Renewables vs Energy Efficiency] Where should i spend my money if i want to have a low carbon home?
| |
− | * [http://europa.eu.int/comm/energy/res/index_en.htm European Union website about renewable energy]
| |
− | * [http://www.rengen.info/?p=6 The wide world of renewable energy]
| |
− | * [http://www.offshorewind.net Offshorewind.net] Information on offshore wind energy in the United States.
| |
− | * [http://www.sterlingplanet.com sterling Planet]
| |
− | * [http://www.southerngrease.com Renewable Energy - Beginner's tutorial on using renewable fuel in a diesel engine]
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| | | |
− | == References == | + | <!--T:39--> |
− | <references/>
| + | {{Bible verse |
− | *[http://eia.doe.gov/ U.S. Energy Information Administration] provides a wide range of statistics and information on the industry.
| + | |book=2 Kings |
− | *Boyle, G. (ed.), ''Renewable Energy: Power for a Sustainable Future''. Open University, UK, 1996.
| + | |chapter=1 |
− | *[http://www.eere.energy.gov/ U.S. DOE Energy Efficiency and Renewable Energy (EERE) Home Page]
| + | |verse=12 |
| + | |version=KJV |
| + | |text= |
| + | “And Elijah answered and said unto them, If I be a man of God, let fire come down from heaven, and consume thee and thy fifty. And the fire of God came down from heaven, and consumed him and his fifty.” |
| + | }} |
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− | [[Category:Climate change]]
| + | <!--T:75--> |
− | [[Category:Renewable energy|*]]
| + | <noinclude></translate></noinclude> |
− | [[Category:Sustainability]]
| + | {{CloseReq}} <!-- 11 --> |
| + | <noinclude><translate></noinclude> |
| + | ==References== <!--T:40--> |
| + | <noinclude></translate></noinclude> |
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− | [[cy:Egni cynaliadwy]] | + | [[Category:Adventist Youth Honors Answer Book/Do at home{{GetLangSuffix}}]] |
− | [[da:Vedvarende energi]]
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− | [[de:Erneuerbare Energie]]
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− | [[es:Energía renovable]]
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− | [[eo:Renoviĝanta energio]]
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− | [[fr:Énergie renouvelable]]
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− | [[id:Energi terbaharui]]
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− | [[it:Energie rinnovabili]]
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− | [[he:אנרגיה חלופית]]
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− | [[lb:Erneierbar Energie]]
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− | [[nl:Duurzame energie]]
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− | [[ja:再生可能エネルギー]]
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− | [[no:Fornybar energi]]
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− | [[pl:Odnawialne źródła energii]]
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− | [[pt:Energia renovável]]
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− | [[ro:Energie reînnoibilă]]
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− | [[sl:Obnovljivi viri energije]]
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− | [[fi:Uusiutuva luonnonvara]]
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− | [[th:พลังงานทดแทน]]
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− | [[vi:Năng lượng tái tạo]]
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− | [[zh:可再生能源]]
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