Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Energy Development shopping experience:

1. Compare - without doubt the biggest advantage that the Energy Development offers shoppers today is the ability to compare thousands of Energy Development at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.

2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about

3. Testimonials - don't know anybody that has bought a Energy Development? Wrong! If the Energy Development is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.

4. Questions - Got a question about Energy Development then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....

5. Reputation - Never heard of the company selling Energy Development? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Energy Development and build up a picture of their reputation for sales, returns, customer service, delivery etc.

6. Returns - still worried that even after all of the above your Energy Development wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.

7. Feedback - happy with your Energy Development then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.

8. Security - check for the yellow padlock on the Energy Development site before you buy, and the s after http:/ /i.e. https:// = a secure site

9. Contact - got a question about Energy Development, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.

10. Payment - ready to pay for your Energy Development, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.

Energy development is the ongoing effort to provide sustainable energy resources through knowledge, skills, and constructions. When wikt:harnessing energy from primary energy sources and converting them into more convenient secondary energy forms, such as electrical energy and cleaner fuel, both emissions (reducing pollution) and quality (more efficient use) are important. Dependence on external energy sources Technologically advanced societies have become increasingly dependent on external energy sources for transportation, the production of many manufactured goods, and the delivery of energy services. This energy allows people, in general, to live under otherwise unfavorable climatic conditions through the use of HVAC. Level of use of external energy sources differs across societies, as do the climate, convenience, traffic congestion, pollution, Gross Domestic Product, and greenhouse gas emissions of each society.

Increased levels of human comfort generally induce increased dependence on external energy sources, although the application of energy efficiency and energy conservation approaches allows a certain degree of mitigation of the dependence. Wise energy use therefore embodies the idea of balancing human comfort with reasonable energy consumption levels by researching and implementing effective and sustainable energy harvesting and utilization measures.



Limitations to energy development A key limit to the development of any particular energy source is availability of the underlying resource. Most of the world's main energy sources are based on the consumption of non-renewable resources (petroleum, coal, natural gas, and uranium). While still a small segment of the energy supply, renewable sources such as wind power and solar power are growing rapidly in market share.

Closely linked to energy development are concerns about the possible The environment effects of energy use, such as climate changes. Energy development issues are part of the much debated sustainable development problem.

Primary energy sources Primary energy sources are substances or processes with concentrations of energy at a high enough potential to be feasibly encouraged to convert to lower energy forms under human control for human benefit. Except for nuclear fuels, tidal energy and geothermal energy, all terrestrial energy sources are from current solar insolation or from fossil remains of plant and animal life that relied directly and indirectly upon sunlight, respectively. And ultimately, solar power itself is the result of the Sun's nuclear fusion. Geothermal power from hot, hardened Rock (geology) above the magma of the earth's core is the result of the accumulation of radioactive materials during the formation of Earth which was the Supernova#Source of heavy elements of a previous supernova event.

Fossil fuels Fossil fuels, in terms of energy, involve the burning of coal or hydrocarbon fuels, which are the remains of the decomposition of plants and animals. Steam power plant combustion heats water to create steam, which turns a turbine, which, in turn, generates electricity, waste heat, and pollution. There are three main types of fossil fuels: coal, petroleum, and natural gas. Another fossil fuel, liquefied petroleum gas (LPG), is principally derived from the production of natural gas.

Pros

• Because it is based on the simple process of combustion, the burning of fossil fuels can generate large amounts of electricity with a small amount of fuel. Gas-fired power plants are more efficient than coal fired power plants.
• Fossil fuels such as coal are readily available and are currently plentiful. Excluding external costs, coal is less expensive than most other sources of energy because there are large deposits of coal in the world.
• The technology already exists for the use of fossil fuels, though oil and natural gas are approaching peak production and will require a transition to other fuels and/or other measures.
• Commonly used fossil fuels in liquid form such as light crude oil, gasoline, and LPG are easy to distribute.
• LPG can be transported, stored and used virtually anywhere. It does not require a fixed network and will not deteriorate over time. As a result, it is particularly useful in regions which are not connected to fixed energy networks.
• LPG is clean burning and has lower greenhouse gas emissions than any other fossil fuel when measured on a total fuel cycle. In fact, by 2010, all buses and taxis in the Southern Chinese city of Guangzhou will be LP Gas fueled. The city will host the 2010 Asian games and has taken the step in a bid to reduce air pollution in advance of the games.Zhan Lisheng, Date set for LPG-fueled buses, taxis China Daily, July 6, 2007. Retrieved September 7 2007. LPG is also non-toxic and will not contaminate soil or aquifers in the event of a leak.
• LPG can be accessible to everyone everywhere today without major infrastructure investment. There are enough reserves to last many decades.
• LPG can be up to 5 times more efficient than traditional fuels, resulting in less energy wastage and better use of our planet’s resources.

Cons

• The combustion of fossil fuels leads to the release of pollution into the Earth's atmosphere. According to the Union of Concerned Scientists, a typical coal plant produces in one year:http://www.ucsusa.org/clean_energy/coalvswind/c02c.html
• 3,700,000 tons of carbon dioxide (CO2), the primary human cause of global warming.
• 10,000 tons of sulfur dioxide (SO2), the leading cause of acid rain.
• 500 tons of small airborne particles, which result in chronic bronchitis, aggravated asthma, and premature death, in addition to haze-obstructed visibility.
• 10,200 tons of nitrogen oxides (NOx), leading to formation of ozone (smog) which inflames the lungs, burning lung tissue making people more susceptible to respiratory illness.
• 720 tons of carbon monoxide (CO), resulting in headaches and additional stress on people with heart disease.
• 220 tons of hydrocarbons, volatile organic compounds (VOC), which form ozone.
• 170 pounds of mercury, where just 1/70th of a teaspoon deposited on a 25-acre lake can make the fish unsafe to eat.
• 225 pounds of arsenic, which will cause cancer in one out of 100 people who drink water containing 50 parts per billion.
• 114 pounds of lead, 4 pounds of cadmium, other toxic heavy metals, and trace amounts of uranium.
• Dependence on fossil fuels from volatile regions or countries creates energy security risks for dependent countries. Oil dependence in particular has led to monopolization, war, and socio-political instability.
• They are considered non-renewable energy resources, which will eventually Peak oil and become exhausted, with dire consequences to societies that remain highly dependent on them. Fossil fuels are actually slowly forming continuously, but we are using them up at a rate approximately 100,000 times faster than they are formed.

burns natural gas to produce electricity in California.

• Extracting fossil fuels is becoming more difficult as we consume the most accessible fuel deposits. Extraction of fossil fuels is becoming more expensive and more dangerous as Minings get deeper and oil rigs go further out to sea.http://www.rigzone.com/analysis/rigs/insight.asp?i_id=213
• Extraction of fossil fuels can result in extensive environmental degradation, such as the strip mining and mountaintop removal of coal.

from an oil refinery.

• The drilling and transportation of petroleum can result in accidents that result in the despoilation of hundreds of kilometers of beaches and the death or elimination of many forms of wildlife in the area.
• Safety measures are necessary in order to use LPG without incident.
• The storage of these fuels can result in accidents with explosions and poisoning of the atmosphere and groundwater.

Biomass, biofuels, and vegetable oil residue can be used as a biofuel Main articles: Alcohol fuel, Biomass, Vegetable oil economy, vegetable oil as fuel, biodiesel

Biomass production involves using waste or other renewable energy resources such as corn or other vegetation, to generate electricity. When garbage decomposition the methane produced is captured in pipes and later burned to produce electricity. Vegetation and wood can be burned directly, like fossil fuels, to generate energy, or processed to form alcohols.

Vegetable oil is generated from sunlight and CO2 by plants. It is safer to use and store than gasoline or diesel as it has a higher flash point. Straight vegetable oil works in diesel engines if it is heated first. Vegetable oil can also be transesterified to make biodiesel which burns like normal diesel.

Pros

• Biomass production can be used to burn organic waste products resulting from agriculture. This type of recycling encourages the philosophy that nothing on this Earth should be wasted. The result is less demand on the Earth's resources, and a higher carrying capacity for Earth because non-renewable fossil fuels are not consumed.
• Biomass is abundant on Earth and is generally renewable. In theory, we will never run out of organic waste products as fuel, because we are continuously producing them. In addition, biomass is found throughout the world, a fact that should alleviate energy pressures in third world nations.
• When methods of biomass production other than direct combustion of plant mass, such as Fermentation (biochemistry) and pyrolysis, are used, there is little effect on the environment. Alcohols and other fuels produced by these alternative methods are clean burning and are feasible replacements to fossil fuels.

• Since CO2 is first taken out of the atmosphere to make the vegetable oil and then put back after it is burned in the engine, there is no net increase in CO2. So vegetable oil does not contribute to the problem of greenhouse gas.
• It has a high flash point and is safer than most fuels.
• Transitioning to vegetable oil could be relatively easy as biodiesel works where diesel works, and straight vegetable oil takes relatively minor modifications.
• The World already produces more than 100 billion gallons a year for food industry, so we have experience making it.
• Algaculture has the potential to produce far more vegetable oil per acre than current plants.
• Infrastructure for biodiesel around the World is significant and growing.

Cons

• Direct combustion without emissions filtering generally leads to air pollution similar to Flue gas emissions from fossil fuel combustion.
• Producing Biomass to liquid from biomass is generally less cost-effectiveness than from petroleum, since the production of biomass and its subsequent conversion to alcohols is particularly expensive.
• Some researchers claim that, when biomass crops are the product of intensive farming, ethanol fuel production results in a net loss of energy after one accounts for the fuel costs of fertilizer production, farm equipment, and the distillation process.
• Direct competition with land use for food production.

• Current production methods would require enormous amounts of land to replace all gasoline and diesel. With current technology, it is unfeasible for biofuels to replace the demand for petroleum.
• Growth in vegetable oil production is already resulting in deforestation.
• Converting forest land to vegetable oil production can result in a net increase in CO2.
• Demand for vegetable oil used as a fuel may drive up prices of vegetable oils in the food industry
• Costs to modify existing engines may outweigh fuel cost savings

Hydroelectric energy In hydro energy, the gravitational descent of a river is compressed from a long run to a single location with a dam or a flume. This creates a location where concentrated pressure and flow can be used to turn turbines or water wheels, which drive a mechanical watermill or an electric generator.

Pros

• Hydroelectric power stations can promptly increase to full capacity, unlike other types of power stations. This is because water can be accumulated above the dam and released to coincide with peaks in demand.
• Electricity can be generated constantly, so long as sufficient water is available.
• Hydroelectric power produces no primary waste or pollution.
• Hydropower is a renewable resource.
• Hydroelectricity assists in securing a country's access to energy supplies.

Cons

• The construction of a dam can have a serious environmental impact on the surrounding areas. The amount and the quality of water downstream can be affected, which affects plant life both aquatic plant, and land-based. Because a river valley is being flooded, the delicate local habitat of many species are destroyed, while people living nearby may have to relocate their homes.
• Hydroelectricity can only be used in areas where there is a sufficient supply of water.
• Flooding submerges large forests (if they have not been harvested). The resulting anaerobic decomposition of the carboniferous materials releases methane, a GHG.
• Dams can contain huge amounts of water. As with every energy storage system, failure of containment can lead to catastrophic results, e.g. flooding.
• Hydroelectric plants rarely can be erected near load centres, requiring large transmission lines.

Nuclear energy Nuclear power station.

Nuclear power plant use nuclear fission to generate energy by the reaction of uranium-235 inside a nuclear reactor. The reactor uses uranium rod (shaft)s, the atoms of which are split in the process of nuclear fission, releasing a large amount of energy. The process continues as a chain reaction with other atomic nucleus. The heat released heats water to create steam, which spins a turbine generator, producing electricity. A relatively small number of nuclear power plants (about 50) has the potential to supply the entire U.S. (or other nation) with relatively clean electricity.(1997). Developing nations score much lower on these variables than developed nations. The continued rapid economic growth and increase in living standards in developing nations with large populations, like China and India, is dependent on a rapid and large expansion of energy production capacity. and Eastern Europe. Source: EIA.. Source: EIA.

Depending on the type of fission fuel considered, estimates for existing supply at known usage rates varies from thousands of years for uranium-238 to several decades for the currently popular Uranium-235. At the present use rate, there are (as of 2007) about 70 years left of known uranium-235 reserves economically recoverable at an uranium price of US$ 130/kg. The nuclear industry argue that the cost of fuel is a minor cost factor for fission power, more expensive, more difficult to extract sources of uranium could be used in the future, such as lower-grade ores, and if prices increased enough, from sources such as granite and seawater. Increasing the price of uranium would have little effect on the overall cost of nuclear power; a doubling in the cost of natural uranium would increase the total cost of nuclear power by 5 percent. On the other hand, if the price of natural gas was doubled, the cost of gas-fired power would increase by about 60 percent. Another alternative would be to use thorium as fission fuel. Thorium is three times more abundant in Earth's crust than uranium, and much more of the thorium can be used (or, more precisely, converted into Uranium-233 and then used).

Current light water reactors burn the nuclear fuel poorly, leading to energy waste. Nuclear reprocessing or burning the fuel better using different reactor designs would reduce the amount of waste material generated and allow better use of the available resources. As opposed to current light water reactors which use uranium-235 (0.7 percent of all natural uranium), fast breeder convert the more abundant uranium-238 (99.3 percent of all natural uranium) into plutonium for fuel. It has been estimated that there is anywhere from 10,000 to five billion years worth of Uranium-238 for use in these power plants . Breeder technology has been used in several reactors. However, the breeder reactor at Dounreay in Scotland, Monju in Japan and the Superphénix at Creys-Malville in France, in particular, have all had difficulties and were not economically competitive and have been Nuclear decommissioning. The People's Republic of China intends to build breeders.http://www.nti.org/db/china/fbrprog.htm

The possibility of nuclear meltdowns and other reactor accidents, such as the Three Mile Island accident and the Chernobyl disaster, have caused much public fear. Research is being done to lessen the known problems of current reactor technology by developing automated and Passive nuclear safety reactors. Historically, however, coal and hydropower power generation have both been the cause of more deaths per energy unit produced than nuclear power generation. Various kinds of energy infrastructure might be attacked by Terrorism, including nuclear power plants, hydropower plants, and liquified natural gas tankers. Nuclear proliferation is the spread from nation to nation of nuclear technology, including nuclear power plants but especially nuclear weapons. New technology like SSTAR ("small, sealed, transportable, autonomous reactor") may lessen this risk.

The long-term radioactive waste storage problems of nuclear power have not been fully solved. Several countries have considered using underground repositories. Nuclear waste takes up little space compared to wastes from the chemical industry which remain toxic indefinitely. Spent fuel rods are now stored in concrete casks close to the nuclear reactors. The amounts of waste can be reduced in several ways. Both nuclear reprocessing and fast breeder reactors can reduce the amounts of waste. Subcritical reactors or fusion reactors could greatly reduce the time the waste has to be stored. Subcritical reactors may also be able to do the same to already existing waste.

The Economics of new nuclear power plants of nuclear power is not simple to evaluate, because of high capital costs for building and very low fuel costs. Comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear plants. See Economics of new nuclear power plants.

Depending on the source different energy return on energy investment (EROI) are claimed. Advocates (using life cycle analysis) argue that it takes 4-5 months of energy production from the nuclear plant to fully pay back the initial energy investment. Opponents claim that it depends on the grades of the ores ,the fuel came from, so a fully pay back can vary from 10 to 18 years. http://www10.antenna.nl/wise/537/gl/clean.html "World Information Service on Energy" 10-18 years for payback on nuclear energy

Advocates also claim that it is possible to relatively rapidly increase the number of plants. Typical new reactor designs have a construction time of three to four years. In 1983, 43 plants were being built, before an unexpected fall in fossil fuel prices stopped most new construction. Developing countries like India and China are rapidly increasing their nuclear energy use. However, a Council on Foreign Relations report on nuclear energy argues that a rapid expansion of nuclear power may create shortages in building materials such as reactor-quality concrete and steel, skilled workers and engineers, and safety controls by skilled inspectors. This would drive up current prices.

Pros

• The energy content of a kilogram of uranium or thorium, if spent nuclear fuel is nuclear reprocessing and fully utilized, is equivalent to about 3.5 million kilograms of coal.

• The cost of making nuclear power, with current legislation, is about the same as making coal power, which is considered very inexpensive (see Economics of new nuclear power plants). If a carbon tax is applied, nuclear does not have to pay anything because nuclear does not emit toxic gases such as CO2, NO, CO, SO2, arsenic, etc. that are emitted by coal power plants.

• Nuclear power plants are guarded with the nuclear reactor inside a reinforced containment building, and thus are relatively impervious to terrorist attack or adverse weather conditions (see Nuclear safety in the U.S.).

• Because of the fear of a nuclear disaster, nuclear safety has become a major issue.

• Nuclear power does not produce any primary air pollution or release carbon dioxide and sulfur dioxide into the Earth's atmosphere. Therefore, it contributes only a small amount to global warming or acid rain.

• Coal mining is the second most dangerous occupation in the United States. http://www.msnbc.msn.com/id/10725454/ Nuclear energy is much safer per capita than coal derived energy.

• For the same amount of electricity, the life cycle emissions of nuclear is about 4% of coal power. Depending on the report, hydro, wind, and geothermal are sometimes ranked lower, while wind and hydro are sometimes ranked higher (by life cycle emissions).http://www.nei.org/keyissues/protectingtheenvironment/lifecycleemissionsanalysis/ http://dailyreferendum.blogspot.com/2007/08/go-nuclear-go-green-life-cycle.html

• According to a Stanford study, fast breeder have the potential to power humans on earth for billions of years, making it sustainable.

Cons

• The operation of an Containment building nuclear reactor near human settlements can be catastrophic, as shown by the Chernobyl disaster in the Ukraine (former USSR), where large areas of land were affected by radioactive contamination.

• Spent nuclear fuel produced from nuclear fission of uranium is both poisonous and highly radioactive, requiring Maintenance, repair and operations and monitoring at the storage sites. Moreover, the long-term radioactive waste of the long-lived nuclear waste causes serious problems, since (unless the spent fuel is reprocessed) it takes from one to three thousand years for the spent fuel to come back to the natural radioactivity of the uranium ore body that was mined to produce it.

• There can be connections between nuclear power and nuclear weapon proliferation, since both require large-scale uranium enrichment facilities. While civilian nuclear facilities are normally overseen internationally by the IAEA, a couple of countries with such facilities refuse oversight.

• Large capital cost. Building a nuclear power plant requires a huge investment and the costs of safe disassembling (called decommissioning) after it reaches end of usable life must be factored into the full lifecycle budget (see Economics of new nuclear power plants).

• Nuclear fuels are a non-renewable energy source, with unknown high concentration ore reserves. There is a large amount of trace concentration nuclear material in seawater and most rocks; however, extraction from these is not currently economically competitive.

• The limited liability for the owner of a nuclear power plant in case of a nuclear accident differs per nation while nuclear installations are sometimes built close to national borders.Schwartz, J. 2004. "Emergency preparedness and response: compensating victims of a nuclear accident." Journal of Hazardous Materials, Volume 111, Issues 1-3, July, 89-96.

• Waste heat disposal becomes an issue at high ambient temperature thus at a time of peak demand the reactor may need to be shut down or have reduced output "TVA reactor shut down; cooling water from river too hot"

Fusion power Fusion power could solve many of the problems of nuclear fission (the technology mentioned above) but, despite research having started in the 1950s, no commercial fusion reactor is expected before 2050 . Many technical problems remain unsolved. Proposed fusion reactors commonly use deuterium, an isotope of hydrogen, as fuel and in most current designs also lithium. Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years.

Wind power ]

This type of energy harnesses the power of the wind to propel the blades of wind turbines. These turbines cause the rotation of magnets, which creates electricity. Wind towers are usually built together on wind farms.

Pros

• Wind power produces no water or air pollution that can contaminate the environment, because there are no chemical reaction involved in wind power generation. Hence, there are no waste by-products, such as carbon dioxide.

• Power from the wind does not contribute to global warming because it does not generate greenhouse gases.

• Wind generation is a renewable energy source of energy, which means that we will never run out of it.

• Wind towers can be beneficial for people living permanently, or temporarily, in remote areas. It may be difficult to transport electricity through wires from a power plant to a far-away location and thus, wind towers can be set up at the remote setting.

• Farming and grazing can still take place on land occupied by wind turbines.

• Those utilizing wind power in a grid-tie configuration will have backup power in the event of a grid outage.

• Due to the ability of wind turbines to coexist within agricultural fields, siting costs are frequently low.

Cons

• Wind is unpredictable, therefore wind power is not predictably available. When the wind speed decreases less electricity is generated.

• Wind farms may be challenged in communities that consider them an eyesore or view obstructor.

• Wind farms, depending on the location and type of turbine, may negatively affect bird migration patterns and may pose a danger to the birds themselves. Newer, larger wind turbines have slower moving blades which are visible to birds.

Solar power , Manchester, England, was clad in PV panels at a cost of £5.5 million. It started feeding electricity to the national grid in November 2005. Main articles: Solar power, Photovoltaics

Solar power involves using solar cells to convert sunlight into electricity, using sunlight hitting solar thermal panels to convert sunlight to heat water or air, using sunlight hitting a parabolic mirror to heat water (producing steam), or using sunlight entering windows for passive solar heating of a building. It would be advantageous to place solar panels in the regions of highest solar radiation. In the Phoenix, Arizona area, for example, the average annual solar radiation is 5.7 kWh/m2/day www.nwic-research.org/npsec/html/human/renew/solar.htm, or 2080.5 kWh/m2/year. Electricity demand in the continental U.S. is 3.7*1012 kW·h per year. Thus, at 100% efficiency, an area of 1.8x10^9 sq. m (around 700 sq miles) would need to be covered with solar panels to replace all current electricity production in the US with solar power, and at 20% efficiency, an area of approximately 3500 sq miles (3% of Arizona's land area). The average solar radiation in the United States is 4.8 kwh/m2/day http://ocsenergy.anl.gov/documents/docs/OCS_EIS_WhitePaper_Solar.pdf, but reaches 8-9 kWh/m2/day in parts of Southwest.

The monetary cost, assuming $500/meter², would be about $5-10 trillion dollars.

Pros

• Solar power imparts no fuel costs.
• Solar power is a renewable energy resource. As long as the Sun exists, its energy will reach Earth.
• Solar power generation releases no water or air pollution, because there is no combustion of fuels.
• In sunny countries, solar power can be used in remote locations, like a wind turbine. This way, isolated places can receive electricity, when there is no way to connect to the electric power transmissions from a plant.
• Solar energy can be used very efficiently for heating (solar ovens, solar water and home heaters) and daylighting.
• Requires no fuel.
• Coincidently, solar energy is abundant in regions that have relatively largest number of people living off grid - in developing regions of Africa, Solar power in India and Latin America. Hence cheap solar, when availabile, opens the opportunity to enhance global electricity access considerably, and possibly in a relatively short time period. Solar Revolution, by Travis Bradford

Cons

• Solar electricity is expensive compared to grid electricity.
• Solar heat and electricity are not available at night and may be unavailable due to weather conditions; therefore, a Intermittent power source#Intermittency: solar energy is required for most applications.
• Limited power density: Average daily insolation in the contiguous U.S. is 3-7 kW·h/m² DOE's Energy Efficiency and Renewable Energy Solar FAQ (see picture)
• Solar cells produce Direct Current which must be converted to Alternating Current (using a grid tie inverter) when used in currently existing distribution grids. This incurs an energy loss of 4-12%. Renewable Resource Data Center - PV Correction Factors
• A photovoltaic power station is expensive to build, and the energy payback time - the time necessary for producing the same amount of energy as needed for building the power device - for photovoltaic cells is about 1-5 years, depending primarily on location.
• Solar panels collect dust and require cleaning. Dust on the panels significantly reduces the transfer of energy from solar radiation to electric current.

Geothermal energy Geothermal energy harnesses the heat energy present underneath the Earth. The hot rock (geology) heat water to produce steam. When holes are drilled in the region, the steam that shoots up is purified and is used to drive turbines, which power electric generators. When the water temperature is below the boiling point of water a binary system is used. A low boiling point liquid is used to drive a turbine and generator in a closed system similar to a refrigeration unit running in reverse.

Pros

• Geothermal energy does not produce air or water pollution if performed correctly.
• Geothermal power plants run continuously day and night with an uptime typically exceeding 95%.
• Once a geothermal power station is implemented, the energy produced from the station is practically free. A small amount of energy is required in order to run a pump, although this pump can be powered by excess energy generated at the plant.
• Geothermal power stations are relatively small, and have a lesser impact on the environment than tidal or hydroelectric plants. Because geothermal technology does not rely on large bodies of water, but rather, small, but powerful jets of water, like geysers, large generating stations can be avoided without losing functionality.

Cons

• Geothermal energy extraction is only practical in certain areas of the world, usually volcanic, where the heated Rock (geology) is sufficiently close to the surface such as to be reached by current drilling technology . Enhanced geothermal technology uses deeper drilling and water injection to generate geothermal power in areas where the earth's crust is thicker.
• Drilling holes underground may release hazardous gases and minerals from deep inside the Earth. It can be problematic to dispose of these subsidiary products in a safe manner.

Energy transportation While new sources of energy are only rarely discovered or made possible by new technologies, distribution (business) technology continually evolves. The use of fuel cells in cars, for example, is an anticipated delivery technology. This section presents some of the more common delivery technologies that have been important to historic energy development. They all rely in some way on the energy sources listed in the previous section..

• Fuels

Shipping is a flexible delivery technology that is used in the whole range of energy development regimes from primitive to highly advanced. Currently, coal, petroleum and their derivatives are delivered by shipping via boat, Rail transport, or road. Petroleum and natural gas may also be delivered via pipeline transport and coal via a Slurry pipeline. Refined hydrocarbon fuels such as gasoline and Liquified petroleum gas may also be delivered via aircraft. Natural gas pipelines must maintain a certain minimum pressure to function correctly

• Electric grids

Electricity grids are the electrical network used to Electric power transmission and Electricity distribution electric power from production source to end user, when the two may be hundreds of kilometres away. Sources include electrical generation plants such as a nuclear reactor, coal burning power plant, etc. A combination of sub-stations, transformers, towers, cables, and piping are used to maintain a constant flow of electricity. Grids may suffer from transient Power blackouts and power outage, often due to weather damage. During certain extreme space weather events solar wind can interfere with transmissions. Grids also have a predefined carrying capacity or load that cannot safely be exceeded. When power requirements exceed what's available, failures are inevitable. To prevent problems, power is then rationed.

Industrialised countries such as Canada, the United States, and Australia are among the highest per capita consumers of electricity in the world, which is possible thanks to a widespread electrical distribution network. The US grid is one of the most advanced, although infrastructure maintenance is becoming a problem. The electrical power industry is one of the most heavily subsidized.

CurrentEnergy provides a realtime overview of the electricity supply and demand for California, Texas, and the Northeast of the US. African countries with small scale electrical grids have a correspondingly low annual per capita usage of electricity. One of the most powerful power grids in the world supplies power to the state of Queensland, Australia.

Energy storage Main articles: Energy storage, grid energy storage

Methods of energy storage have been developed, which transform electrical energy into forms of potential energy. A method of energy storage may be chosen based on stability, ease of transport, ease of energy release, or ease of converting free energy from the natural form to the stable form.

Battery-powered Vehicles Main articles: battery (electricity), battery electric vehicle Batteries are used to store energy in a chemical form. As an alternative energy, batteries can be used to store energy in battery electric vehicles. Battery electric vehicles can be charged from the grid when the vehicle is not in use. Because the energy is derived from electricity, battery electric vehicles make it possible to use other forms of alternative energy such as wind, solar, geothermal, nuclear, or hydroelectric.

Pros

• Produces zero emissions to help counteract the effects of global warming.
• Batteries are a mature technology, no new expensive research and development is needed to implement technology.
• Current lead acid battery technology offers 50+ miles range on one charge. http://www.kingoftheroad.net/charge_across_america/charge_html/nimh_test2.html
• The Tesla Roadster has a 200 mile range on one charge.
• Batteries make it possible for stationary alternative energy generation such as solar, wind, hydroelectric, nuclear, or hydroelectric.
• Electric motors are 90% efficient compared to about 20% efficiency of an internal combustion engine. http://ffden-2.phys.uaf.edu/102spring2002_Web_projects/Z.Yates/Zach's%20Web%20Project%20Folder/EICE%20-%20Main.htm
• No new major infrastructure is needed to charge battery electric vehicles.
• Battery electric vehicles have fewer moving parts than internal combustion engines, thus improving the reliability of the vehicle.
• Battery electric vehicles are quiet compared to internal combustion engines.
• Multiple electric vehicles sold out including the General Motors EV1 and the Tesla Roadster proving the demand for battery electric vehicles.
• Operation of a battery electric vehicle is approximately 2 to 4 cents per mile. About a sixth the price of operating a gasoline vehicle. Idaho National Laboratory (2005) "Comparing Energy Costs per Mile for Electric and Gasoline-Fueled Vehicles" Advanced Vehicle Testing Activity report at avt.inel.gov accessed 11 July 2006.
• The use of Battery Electric Vehicles eliminates the dependency on foreign oil.

Cons

• The energy used in electric vehicles needs to be derived from other sources.
• Current battery technology is expensive.
• Battery electric vehicles have a relative short range compared to internal combustion engine vehicles.

Hydrogen economy Hydrogen can be manufactured at roughly 77 percent thermal efficiency by the method of steam reforming of natural gas http://cta.ornl.gov/data/index.shtml. When manufactured by this method it is a derivative fuel like gasoline; when produced by electrolysis of water, it is a form of chemical energy storage as are storage battery (electricity), though hydrogen is the more versatile storage mode since there are two options for its conversion to useful work: (1) a fuel cell can convert the chemicals hydrogen and oxygen into water, and in the process, produce electricity, or (2) hydrogen can be burned (less efficiently than in a fuel cell) in an internal combustion engine.

Pros

• Hydrogen is colorless, odorless and entirely non-polluting, yielding pure water vapor (with minimal NOx) as exhaust when combusted in air. This eliminates the direct production of exhaust gases that lead to smog, and carbon dioxide emissions that enhance the effect of global warming.
• Hydrogen is the lightest chemical element and has the best energy-to-weight ratio of any fuel (not counting tank mass).
• Hydrogen can be produced anywhere; it can be produced domestically from the decomposition of water. Hydrogen can be produced from domestic sources and the price can be established within the country.
• Electrolysis combined with fuel-cell regeneration is more than 50% efficient.

Cons

• Other than some volcanic emanations, hydrogen does not exist in its pure form in the environment, because it reacts so strongly with oxygen and other elements.
• It is impossible to obtain hydrogen gas without expending energy in the process. There are three ways to manufacture hydrogen;
• By breaking down hydrocarbons — mainly methane. If oil or gases are used to provide this energy, fossil fuels are consumed, forming pollution and nullifying the value of using a fuel cell. It would be more efficient to use fossil fuel directly.
• By electrolysis from water — The process of splitting water into oxygen and hydrogen using electrolysis consumes large amounts of energy. It has been calculated that it takes 1.4 joules of electricity to produce 1 joule of hydrogen (Pimentel, 2002).
• By reacting water with a metal such as sodium, potassium, or boron. Chemical by-products would be sodium oxide, potassium oxide, and boron oxide. Processes exist which could recycle these elements back into their metal form for re-use with additional energy input, further eroding the EROEI.
• There is currently modest infrastructure for distribution (business) of hydrogen that is centrally produced,http://www.praxair.com/praxair.nsf/d63afe71c771b0d785256519006c5ea1/2a5df393598d7f3b85256baf000827be?OpenDocument&Highlight=2,hydrogen amounting to several hundred kilometers of pipeline. An alternative would be transmission of electricity over the existing electrical network to small-scale electrolyzers to support the widespread use of hydrogen as a fuel.
• Hydrogen is difficult to handle, store, and transport. It requires heavy, cumbersome tanks when stored as a gas, and complex insulating bottles if stored as a cryogenic liquid. If it is needed at a moderate temperature and pressure, a metal hydride absorber may be needed. The transportation of hydrogen is also a problem because hydrogen leaks effortlessly from containers.
• Some current fuel cell designs, such as proton exchange membrane fuel cells, use platinum as a catalyst. Widescale deployment of such fuel cells could place a strain on available platinum resources. Study: World May Run Out of Copper Reducing the platinum loading, per fuel cell stack, is the focus of R&D.
• Electrical power industry and battery electric vehicles are far more efficient for storage, transmission and use of energy for transportation, neglecting the energy conversion at the electric power plant. As with distributed production of hydrogen via electrolysis, battery electric vehicles could utilize the existing electricity grid until widespread use dictated an expansion of the grid.

Energy Storage Types

• Chemical

Some natural forms of energy are found in stable chemical compounds such as fossil fuels. Most systems of chemical energy storage result from Biology activity, which store energy in chemical bonds. Man-made forms of chemical energy storage include hydrogen fuel, battery (electricity) and explosives such as cordite and dynamite.

• Gravitational

Dams can be used to store energy, by using excess energy to pump water into the reservoir. When electrical energy is required, the process is reversed. The water then turns a turbine, generating electricity. Hydroelectric power is currently an important part of the world's energy supply, generating one-fifth of the world's electricity. :.

• Electrical capacitance

Electrical energy may be stored in capacitors. Capacitors are often used to produce high intensity releases of energy (such as a camera's flash).

• Mechanical

*Pressure: :Energy may also be stored pressure gases or alternatively in a vacuum. Compressed air, for example, may be used to operate vehicles and power tools. Large scale compressed air energy storage facilities are used to smooth out demands on electricity generation by providing energy during peak hours and storing energy during off-peak hours. Such systems save on expensive generating capacity since it only needs to meet average consumption rather than peak consumption. *Flywheels and springs Energy development is the ongoing effort to provide sustainable energy resources through knowledge, skills, and constructions. When wikt:harnessing energy from primary energy sources and converting them into more convenient secondary energy forms, such as electrical energy and cleaner fuel, both emissions (reducing pollution) and quality (more efficient use) are important. Dependence on external energy sources Technologically advanced societies have become increasingly dependent on external energy sources for transportation, the production of many manufactured goods, and the delivery of energy services. This energy allows people, in general, to live under otherwise unfavorable climatic conditions through the use of HVAC. Level of use of external energy sources differs across societies, as do the climate, convenience, traffic congestion, pollution, Gross Domestic Product, and greenhouse gas emissions of each society.

Increased levels of human comfort generally induce increased dependence on external energy sources, although the application of energy efficiency and energy conservation approaches allows a certain degree of mitigation of the dependence. Wise energy use therefore embodies the idea of balancing human comfort with reasonable energy consumption levels by researching and implementing effective and sustainable energy harvesting and utilization measures.



Limitations to energy development A key limit to the development of any particular energy source is availability of the underlying resource. Most of the world's main energy sources are based on the consumption of non-renewable resources (petroleum, coal, natural gas, and uranium). While still a small segment of the energy supply, renewable sources such as wind power and solar power are growing rapidly in market share.

Closely linked to energy development are concerns about the possible The environment effects of energy use, such as climate changes. Energy development issues are part of the much debated sustainable development problem.

Primary energy sources Primary energy sources are substances or processes with concentrations of energy at a high enough potential to be feasibly encouraged to convert to lower energy forms under human control for human benefit. Except for nuclear fuels, tidal energy and geothermal energy, all terrestrial energy sources are from current solar insolation or from fossil remains of plant and animal life that relied directly and indirectly upon sunlight, respectively. And ultimately, solar power itself is the result of the Sun's nuclear fusion. Geothermal power from hot, hardened Rock (geology) above the magma of the earth's core is the result of the accumulation of radioactive materials during the formation of Earth which was the Supernova#Source of heavy elements of a previous supernova event.

Fossil fuels Fossil fuels, in terms of energy, involve the burning of coal or hydrocarbon fuels, which are the remains of the decomposition of plants and animals. Steam power plant combustion heats water to create steam, which turns a turbine, which, in turn, generates electricity, waste heat, and pollution. There are three main types of fossil fuels: coal, petroleum, and natural gas. Another fossil fuel, liquefied petroleum gas (LPG), is principally derived from the production of natural gas.

Pros

• Because it is based on the simple process of combustion, the burning of fossil fuels can generate large amounts of electricity with a small amount of fuel. Gas-fired power plants are more efficient than coal fired power plants.
• Fossil fuels such as coal are readily available and are currently plentiful. Excluding external costs, coal is less expensive than most other sources of energy because there are large deposits of coal in the world.
• The technology already exists for the use of fossil fuels, though oil and natural gas are approaching peak production and will require a transition to other fuels and/or other measures.
• Commonly used fossil fuels in liquid form such as light crude oil, gasoline, and LPG are easy to distribute.
• LPG can be transported, stored and used virtually anywhere. It does not require a fixed network and will not deteriorate over time. As a result, it is particularly useful in regions which are not connected to fixed energy networks.
• LPG is clean burning and has lower greenhouse gas emissions than any other fossil fuel when measured on a total fuel cycle. In fact, by 2010, all buses and taxis in the Southern Chinese city of Guangzhou will be LP Gas fueled. The city will host the 2010 Asian games and has taken the step in a bid to reduce air pollution in advance of the games.Zhan Lisheng, Date set for LPG-fueled buses, taxis China Daily, July 6, 2007. Retrieved September 7 2007. LPG is also non-toxic and will not contaminate soil or aquifers in the event of a leak.
• LPG can be accessible to everyone everywhere today without major infrastructure investment. There are enough reserves to last many decades.
• LPG can be up to 5 times more efficient than traditional fuels, resulting in less energy wastage and better use of our planet’s resources.

Cons

• The combustion of fossil fuels leads to the release of pollution into the Earth's atmosphere. According to the Union of Concerned Scientists, a typical coal plant produces in one year:http://www.ucsusa.org/clean_energy/coalvswind/c02c.html
• 3,700,000 tons of carbon dioxide (CO2), the primary human cause of global warming.
• 10,000 tons of sulfur dioxide (SO2), the leading cause of acid rain.
• 500 tons of small airborne particles, which result in chronic bronchitis, aggravated asthma, and premature death, in addition to haze-obstructed visibility.
• 10,200 tons of nitrogen oxides (NOx), leading to formation of ozone (smog) which inflames the lungs, burning lung tissue making people more susceptible to respiratory illness.
• 720 tons of carbon monoxide (CO), resulting in headaches and additional stress on people with heart disease.
• 220 tons of hydrocarbons, volatile organic compounds (VOC), which form ozone.
• 170 pounds of mercury, where just 1/70th of a teaspoon deposited on a 25-acre lake can make the fish unsafe to eat.
• 225 pounds of arsenic, which will cause cancer in one out of 100 people who drink water containing 50 parts per billion.
• 114 pounds of lead, 4 pounds of cadmium, other toxic heavy metals, and trace amounts of uranium.
• Dependence on fossil fuels from volatile regions or countries creates energy security risks for dependent countries. Oil dependence in particular has led to monopolization, war, and socio-political instability.
• They are considered non-renewable energy resources, which will eventually Peak oil and become exhausted, with dire consequences to societies that remain highly dependent on them. Fossil fuels are actually slowly forming continuously, but we are using them up at a rate approximately 100,000 times faster than they are formed.

burns natural gas to produce electricity in California.

• Extracting fossil fuels is becoming more difficult as we consume the most accessible fuel deposits. Extraction of fossil fuels is becoming more expensive and more dangerous as Minings get deeper and oil rigs go further out to sea.http://www.rigzone.com/analysis/rigs/insight.asp?i_id=213
• Extraction of fossil fuels can result in extensive environmental degradation, such as the strip mining and mountaintop removal of coal.

from an oil refinery.

• The drilling and transportation of petroleum can result in accidents that result in the despoilation of hundreds of kilometers of beaches and the death or elimination of many forms of wildlife in the area.
• Safety measures are necessary in order to use LPG without incident.
• The storage of these fuels can result in accidents with explosions and poisoning of the atmosphere and groundwater.

Biomass, biofuels, and vegetable oil residue can be used as a biofuel Main articles: Alcohol fuel, Biomass, Vegetable oil economy, vegetable oil as fuel, biodiesel

Biomass production involves using waste or other renewable energy resources such as corn or other vegetation, to generate electricity. When garbage decomposition the methane produced is captured in pipes and later burned to produce electricity. Vegetation and wood can be burned directly, like fossil fuels, to generate energy, or processed to form alcohols.

Vegetable oil is generated from sunlight and CO2 by plants. It is safer to use and store than gasoline or diesel as it has a higher flash point. Straight vegetable oil works in diesel engines if it is heated first. Vegetable oil can also be transesterified to make biodiesel which burns like normal diesel.

Pros

• Biomass production can be used to burn organic waste products resulting from agriculture. This type of recycling encourages the philosophy that nothing on this Earth should be wasted. The result is less demand on the Earth's resources, and a higher carrying capacity for Earth because non-renewable fossil fuels are not consumed.
• Biomass is abundant on Earth and is generally renewable. In theory, we will never run out of organic waste products as fuel, because we are continuously producing them. In addition, biomass is found throughout the world, a fact that should alleviate energy pressures in third world nations.
• When methods of biomass production other than direct combustion of plant mass, such as Fermentation (biochemistry) and pyrolysis, are used, there is little effect on the environment. Alcohols and other fuels produced by these alternative methods are clean burning and are feasible replacements to fossil fuels.

• Since CO2 is first taken out of the atmosphere to make the vegetable oil and then put back after it is burned in the engine, there is no net increase in CO2. So vegetable oil does not contribute to the problem of greenhouse gas.
• It has a high flash point and is safer than most fuels.
• Transitioning to vegetable oil could be relatively easy as biodiesel works where diesel works, and straight vegetable oil takes relatively minor modifications.
• The World already produces more than 100 billion gallons a year for food industry, so we have experience making it.
• Algaculture has the potential to produce far more vegetable oil per acre than current plants.
• Infrastructure for biodiesel around the World is significant and growing.

Cons

• Direct combustion without emissions filtering generally leads to air pollution similar to Flue gas emissions from fossil fuel combustion.
• Producing Biomass to liquid from biomass is generally less cost-effectiveness than from petroleum, since the production of biomass and its subsequent conversion to alcohols is particularly expensive.
• Some researchers claim that, when biomass crops are the product of intensive farming, ethanol fuel production results in a net loss of energy after one accounts for the fuel costs of fertilizer production, farm equipment, and the distillation process.
• Direct competition with land use for food production.

• Current production methods would require enormous amounts of land to replace all gasoline and diesel. With current technology, it is unfeasible for biofuels to replace the demand for petroleum.
• Growth in vegetable oil production is already resulting in deforestation.
• Converting forest land to vegetable oil production can result in a net increase in CO2.
• Demand for vegetable oil used as a fuel may drive up prices of vegetable oils in the food industry
• Costs to modify existing engines may outweigh fuel cost savings

Hydroelectric energy In hydro energy, the gravitational descent of a river is compressed from a long run to a single location with a dam or a flume. This creates a location where concentrated pressure and flow can be used to turn turbines or water wheels, which drive a mechanical watermill or an electric generator.

Pros

• Hydroelectric power stations can promptly increase to full capacity, unlike other types of power stations. This is because water can be accumulated above the dam and released to coincide with peaks in demand.
• Electricity can be generated constantly, so long as sufficient water is available.
• Hydroelectric power produces no primary waste or pollution.
• Hydropower is a renewable resource.
• Hydroelectricity assists in securing a country's access to energy supplies.

Cons

• The construction of a dam can have a serious environmental impact on the surrounding areas. The amount and the quality of water downstream can be affected, which affects plant life both aquatic plant, and land-based. Because a river valley is being flooded, the delicate local habitat of many species are destroyed, while people living nearby may have to relocate their homes.
• Hydroelectricity can only be used in areas where there is a sufficient supply of water.
• Flooding submerges large forests (if they have not been harvested). The resulting anaerobic decomposition of the carboniferous materials releases methane, a GHG.
• Dams can contain huge amounts of water. As with every energy storage system, failure of containment can lead to catastrophic results, e.g. flooding.
• Hydroelectric plants rarely can be erected near load centres, requiring large transmission lines.

Nuclear energy Nuclear power station.

Nuclear power plant use nuclear fission to generate energy by the reaction of uranium-235 inside a nuclear reactor. The reactor uses uranium rod (shaft)s, the atoms of which are split in the process of nuclear fission, releasing a large amount of energy. The process continues as a chain reaction with other atomic nucleus. The heat released heats water to create steam, which spins a turbine generator, producing electricity. A relatively small number of nuclear power plants (about 50) has the potential to supply the entire U.S. (or other nation) with relatively clean electricity.(1997). Developing nations score much lower on these variables than developed nations. The continued rapid economic growth and increase in living standards in developing nations with large populations, like China and India, is dependent on a rapid and large expansion of energy production capacity. and Eastern Europe. Source: EIA.. Source: EIA.

Depending on the type of fission fuel considered, estimates for existing supply at known usage rates varies from thousands of years for uranium-238 to several decades for the currently popular Uranium-235. At the present use rate, there are (as of 2007) about 70 years left of known uranium-235 reserves economically recoverable at an uranium price of US$ 130/kg. The nuclear industry argue that the cost of fuel is a minor cost factor for fission power, more expensive, more difficult to extract sources of uranium could be used in the future, such as lower-grade ores, and if prices increased enough, from sources such as granite and seawater. Increasing the price of uranium would have little effect on the overall cost of nuclear power; a doubling in the cost of natural uranium would increase the total cost of nuclear power by 5 percent. On the other hand, if the price of natural gas was doubled, the cost of gas-fired power would increase by about 60 percent. Another alternative would be to use thorium as fission fuel. Thorium is three times more abundant in Earth's crust than uranium, and much more of the thorium can be used (or, more precisely, converted into Uranium-233 and then used).

Current light water reactors burn the nuclear fuel poorly, leading to energy waste. Nuclear reprocessing or burning the fuel better using different reactor designs would reduce the amount of waste material generated and allow better use of the available resources. As opposed to current light water reactors which use uranium-235 (0.7 percent of all natural uranium), fast breeder convert the more abundant uranium-238 (99.3 percent of all natural uranium) into plutonium for fuel. It has been estimated that there is anywhere from 10,000 to five billion years worth of Uranium-238 for use in these power plants . Breeder technology has been used in several reactors. However, the breeder reactor at Dounreay in Scotland, Monju in Japan and the Superphénix at Creys-Malville in France, in particular, have all had difficulties and were not economically competitive and have been Nuclear decommissioning. The People's Republic of China intends to build breeders.http://www.nti.org/db/china/fbrprog.htm

The possibility of nuclear meltdowns and other reactor accidents, such as the Three Mile Island accident and the Chernobyl disaster, have caused much public fear. Research is being done to lessen the known problems of current reactor technology by developing automated and Passive nuclear safety reactors. Historically, however, coal and hydropower power generation have both been the cause of more deaths per energy unit produced than nuclear power generation. Various kinds of energy infrastructure might be attacked by Terrorism, including nuclear power plants, hydropower plants, and liquified natural gas tankers. Nuclear proliferation is the spread from nation to nation of nuclear technology, including nuclear power plants but especially nuclear weapons. New technology like SSTAR ("small, sealed, transportable, autonomous reactor") may lessen this risk.

The long-term radioactive waste storage problems of nuclear power have not been fully solved. Several countries have considered using underground repositories. Nuclear waste takes up little space compared to wastes from the chemical industry which remain toxic indefinitely. Spent fuel rods are now stored in concrete casks close to the nuclear reactors. The amounts of waste can be reduced in several ways. Both nuclear reprocessing and fast breeder reactors can reduce the amounts of waste. Subcritical reactors or fusion reactors could greatly reduce the time the waste has to be stored. Subcritical reactors may also be able to do the same to already existing waste.

The Economics of new nuclear power plants of nuclear power is not simple to evaluate, because of high capital costs for building and very low fuel costs. Comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear plants. See Economics of new nuclear power plants.

Depending on the source different energy return on energy investment (EROI) are claimed. Advocates (using life cycle analysis) argue that it takes 4-5 months of energy production from the nuclear plant to fully pay back the initial energy investment. Opponents claim that it depends on the grades of the ores ,the fuel came from, so a fully pay back can vary from 10 to 18 years. http://www10.antenna.nl/wise/537/gl/clean.html "World Information Service on Energy" 10-18 years for payback on nuclear energy

Advocates also claim that it is possible to relatively rapidly increase the number of plants. Typical new reactor designs have a construction time of three to four years. In 1983, 43 plants were being built, before an unexpected fall in fossil fuel prices stopped most new construction. Developing countries like India and China are rapidly increasing their nuclear energy use. However, a Council on Foreign Relations report on nuclear energy argues that a rapid expansion of nuclear power may create shortages in building materials such as reactor-quality concrete and steel, skilled workers and engineers, and safety controls by skilled inspectors. This would drive up current prices.

Pros

• The energy content of a kilogram of uranium or thorium, if spent nuclear fuel is nuclear reprocessing and fully utilized, is equivalent to about 3.5 million kilograms of coal.

• The cost of making nuclear power, with current legislation, is about the same as making coal power, which is considered very inexpensive (see Economics of new nuclear power plants). If a carbon tax is applied, nuclear does not have to pay anything because nuclear does not emit toxic gases such as CO2, NO, CO, SO2, arsenic, etc. that are emitted by coal power plants.

• Nuclear power plants are guarded with the nuclear reactor inside a reinforced containment building, and thus are relatively impervious to terrorist attack or adverse weather conditions (see Nuclear safety in the U.S.).

• Because of the fear of a nuclear disaster, nuclear safety has become a major issue.

• Nuclear power does not produce any primary air pollution or release carbon dioxide and sulfur dioxide into the Earth's atmosphere. Therefore, it contributes only a small amount to global warming or acid rain.

• Coal mining is the second most dangerous occupation in the United States. http://www.msnbc.msn.com/id/10725454/ Nuclear energy is much safer per capita than coal derived energy.

• For the same amount of electricity, the life cycle emissions of nuclear is about 4% of coal power. Depending on the report, hydro, wind, and geothermal are sometimes ranked lower, while wind and hydro are sometimes ranked higher (by life cycle emissions).http://www.nei.org/keyissues/protectingtheenvironment/lifecycleemissionsanalysis/ http://dailyreferendum.blogspot.com/2007/08/go-nuclear-go-green-life-cycle.html

• According to a Stanford study, fast breeder have the potential to power humans on earth for billions of years, making it sustainable.

Cons

• The operation of an Containment building nuclear reactor near human settlements can be catastrophic, as shown by the Chernobyl disaster in the Ukraine (former USSR), where large areas of land were affected by radioactive contamination.

• Spent nuclear fuel produced from nuclear fission of uranium is both poisonous and highly radioactive, requiring Maintenance, repair and operations and monitoring at the storage sites. Moreover, the long-term radioactive waste of the long-lived nuclear waste causes serious problems, since (unless the spent fuel is reprocessed) it takes from one to three thousand years for the spent fuel to come back to the natural radioactivity of the uranium ore body that was mined to produce it.

• There can be connections between nuclear power and nuclear weapon proliferation, since both require large-scale uranium enrichment facilities. While civilian nuclear facilities are normally overseen internationally by the IAEA, a couple of countries with such facilities refuse oversight.

• Large capital cost. Building a nuclear power plant requires a huge investment and the costs of safe disassembling (called decommissioning) after it reaches end of usable life must be factored into the full lifecycle budget (see Economics of new nuclear power plants).

• Nuclear fuels are a non-renewable energy source, with unknown high concentration ore reserves. There is a large amount of trace concentration nuclear material in seawater and most rocks; however, extraction from these is not currently economically competitive.

• The limited liability for the owner of a nuclear power plant in case of a nuclear accident differs per nation while nuclear installations are sometimes built close to national borders.Schwartz, J. 2004. "Emergency preparedness and response: compensating victims of a nuclear accident." Journal of Hazardous Materials, Volume 111, Issues 1-3, July, 89-96.

• Waste heat disposal becomes an issue at high ambient temperature thus at a time of peak demand the reactor may need to be shut down or have reduced output "TVA reactor shut down; cooling water from river too hot"

Fusion power Fusion power could solve many of the problems of nuclear fission (the technology mentioned above) but, despite research having started in the 1950s, no commercial fusion reactor is expected before 2050 . Many technical problems remain unsolved. Proposed fusion reactors commonly use deuterium, an isotope of hydrogen, as fuel and in most current designs also lithium. Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years.

Wind power ]

This type of energy harnesses the power of the wind to propel the blades of wind turbines. These turbines cause the rotation of magnets, which creates electricity. Wind towers are usually built together on wind farms.

Pros

• Wind power produces no water or air pollution that can contaminate the environment, because there are no chemical reaction involved in wind power generation. Hence, there are no waste by-products, such as carbon dioxide.

• Power from the wind does not contribute to global warming because it does not generate greenhouse gases.

• Wind generation is a renewable energy source of energy, which means that we will never run out of it.

• Wind towers can be beneficial for people living permanently, or temporarily, in remote areas. It may be difficult to transport electricity through wires from a power plant to a far-away location and thus, wind towers can be set up at the remote setting.

• Farming and grazing can still take place on land occupied by wind turbines.

• Those utilizing wind power in a grid-tie configuration will have backup power in the event of a grid outage.

• Due to the ability of wind turbines to coexist within agricultural fields, siting costs are frequently low.

Cons

• Wind is unpredictable, therefore wind power is not predictably available. When the wind speed decreases less electricity is generated.

• Wind farms may be challenged in communities that consider them an eyesore or view obstructor.

• Wind farms, depending on the location and type of turbine, may negatively affect bird migration patterns and may pose a danger to the birds themselves. Newer, larger wind turbines have slower moving blades which are visible to birds.

Solar power , Manchester, England, was clad in PV panels at a cost of £5.5 million. It started feeding electricity to the national grid in November 2005. Main articles: Solar power, Photovoltaics

Solar power involves using solar cells to convert sunlight into electricity, using sunlight hitting solar thermal panels to convert sunlight to heat water or air, using sunlight hitting a parabolic mirror to heat water (producing steam), or using sunlight entering windows for passive solar heating of a building. It would be advantageous to place solar panels in the regions of highest solar radiation. In the Phoenix, Arizona area, for example, the average annual solar radiation is 5.7 kWh/m2/day www.nwic-research.org/npsec/html/human/renew/solar.htm, or 2080.5 kWh/m2/year. Electricity demand in the continental U.S. is 3.7*1012 kW·h per year. Thus, at 100% efficiency, an area of 1.8x10^9 sq. m (around 700 sq miles) would need to be covered with solar panels to replace all current electricity production in the US with solar power, and at 20% efficiency, an area of approximately 3500 sq miles (3% of Arizona's land area). The average solar radiation in the United States is 4.8 kwh/m2/day http://ocsenergy.anl.gov/documents/docs/OCS_EIS_WhitePaper_Solar.pdf, but reaches 8-9 kWh/m2/day in parts of Southwest.

The monetary cost, assuming $500/meter², would be about $5-10 trillion dollars.

Pros

• Solar power imparts no fuel costs.
• Solar power is a renewable energy resource. As long as the Sun exists, its energy will reach Earth.
• Solar power generation releases no water or air pollution, because there is no combustion of fuels.
• In sunny countries, solar power can be used in remote locations, like a wind turbine. This way, isolated places can receive electricity, when there is no way to connect to the electric power transmissions from a plant.
• Solar energy can be used very efficiently for heating (solar ovens, solar water and home heaters) and daylighting.
• Requires no fuel.
• Coincidently, solar energy is abundant in regions that have relatively largest number of people living off grid - in developing regions of Africa, Solar power in India and Latin America. Hence cheap solar, when availabile, opens the opportunity to enhance global electricity access considerably, and possibly in a relatively short time period. Solar Revolution, by Travis Bradford

Cons

• Solar electricity is expensive compared to grid electricity.
• Solar heat and electricity are not available at night and may be unavailable due to weather conditions; therefore, a Intermittent power source#Intermittency: solar energy is required for most applications.
• Limited power density: Average daily insolation in the contiguous U.S. is 3-7 kW·h/m² DOE's Energy Efficiency and Renewable Energy Solar FAQ (see picture)
• Solar cells produce Direct Current which must be converted to Alternating Current (using a grid tie inverter) when used in currently existing distribution grids. This incurs an energy loss of 4-12%. Renewable Resource Data Center - PV Correction Factors
• A photovoltaic power station is expensive to build, and the energy payback time - the time necessary for producing the same amount of energy as needed for building the power device - for photovoltaic cells is about 1-5 years, depending primarily on location.
• Solar panels collect dust and require cleaning. Dust on the panels significantly reduces the transfer of energy from solar radiation to electric current.

Geothermal energy Geothermal energy harnesses the heat energy present underneath the Earth. The hot rock (geology) heat water to produce steam. When holes are drilled in the region, the steam that shoots up is purified and is used to drive turbines, which power electric generators. When the water temperature is below the boiling point of water a binary system is used. A low boiling point liquid is used to drive a turbine and generator in a closed system similar to a refrigeration unit running in reverse.

Pros

• Geothermal energy does not produce air or water pollution if performed correctly.
• Geothermal power plants run continuously day and night with an uptime typically exceeding 95%.
• Once a geothermal power station is implemented, the energy produced from the station is practically free. A small amount of energy is required in order to run a pump, although this pump can be powered by excess energy generated at the plant.
• Geothermal power stations are relatively small, and have a lesser impact on the environment than tidal or hydroelectric plants. Because geothermal technology does not rely on large bodies of water, but rather, small, but powerful jets of water, like geysers, large generating stations can be avoided without losing functionality.

Cons

• Geothermal energy extraction is only practical in certain areas of the world, usually volcanic, where the heated Rock (geology) is sufficiently close to the surface such as to be reached by current drilling technology . Enhanced geothermal technology uses deeper drilling and water injection to generate geothermal power in areas where the earth's crust is thicker.
• Drilling holes underground may release hazardous gases and minerals from deep inside the Earth. It can be problematic to dispose of these subsidiary products in a safe manner.

Energy transportation While new sources of energy are only rarely discovered or made possible by new technologies, distribution (business) technology continually evolves. The use of fuel cells in cars, for example, is an anticipated delivery technology. This section presents some of the more common delivery technologies that have been important to historic energy development. They all rely in some way on the energy sources listed in the previous section..

• Fuels

Shipping is a flexible delivery technology that is used in the whole range of energy development regimes from primitive to highly advanced. Currently, coal, petroleum and their derivatives are delivered by shipping via boat, Rail transport, or road. Petroleum and natural gas may also be delivered via pipeline transport and coal via a Slurry pipeline. Refined hydrocarbon fuels such as gasoline and Liquified petroleum gas may also be delivered via aircraft. Natural gas pipelines must maintain a certain minimum pressure to function correctly

• Electric grids

Electricity grids are the electrical network used to Electric power transmission and Electricity distribution electric power from production source to end user, when the two may be hundreds of kilometres away. Sources include electrical generation plants such as a nuclear reactor, coal burning power plant, etc. A combination of sub-stations, transformers, towers, cables, and piping are used to maintain a constant flow of electricity. Grids may suffer from transient Power blackouts and power outage, often due to weather damage. During certain extreme space weather events solar wind can interfere with transmissions. Grids also have a predefined carrying capacity or load that cannot safely be exceeded. When power requirements exceed what's available, failures are inevitable. To prevent problems, power is then rationed.

Industrialised countries such as Canada, the United States, and Australia are among the highest per capita consumers of electricity in the world, which is possible thanks to a widespread electrical distribution network. The US grid is one of the most advanced, although infrastructure maintenance is becoming a problem. The electrical power industry is one of the most heavily subsidized.

CurrentEnergy provides a realtime overview of the electricity supply and demand for California, Texas, and the Northeast of the US. African countries with small scale electrical grids have a correspondingly low annual per capita usage of electricity. One of the most powerful power grids in the world supplies power to the state of Queensland, Australia.

Energy storage Main articles: Energy storage, grid energy storage

Methods of energy storage have been developed, which transform electrical energy into forms of potential energy. A method of energy storage may be chosen based on stability, ease of transport, ease of energy release, or ease of converting free energy from the natural form to the stable form.

Battery-powered Vehicles Main articles: battery (electricity), battery electric vehicle Batteries are used to store energy in a chemical form. As an alternative energy, batteries can be used to store energy in battery electric vehicles. Battery electric vehicles can be charged from the grid when the vehicle is not in use. Because the energy is derived from electricity, battery electric vehicles make it possible to use other forms of alternative energy such as wind, solar, geothermal, nuclear, or hydroelectric.

Pros

• Produces zero emissions to help counteract the effects of global warming.
• Batteries are a mature technology, no new expensive research and development is needed to implement technology.
• Current lead acid battery technology offers 50+ miles range on one charge. http://www.kingoftheroad.net/charge_across_america/charge_html/nimh_test2.html
• The Tesla Roadster has a 200 mile range on one charge.
• Batteries make it possible for stationary alternative energy generation such as solar, wind, hydroelectric, nuclear, or hydroelectric.
• Electric motors are 90% efficient compared to about 20% efficiency of an internal combustion engine. http://ffden-2.phys.uaf.edu/102spring2002_Web_projects/Z.Yates/Zach's%20Web%20Project%20Folder/EICE%20-%20Main.htm
• No new major infrastructure is needed to charge battery electric vehicles.
• Battery electric vehicles have fewer moving parts than internal combustion engines, thus improving the reliability of the vehicle.
• Battery electric vehicles are quiet compared to internal combustion engines.
• Multiple electric vehicles sold out including the General Motors EV1 and the Tesla Roadster proving the demand for battery electric vehicles.
• Operation of a battery electric vehicle is approximately 2 to 4 cents per mile. About a sixth the price of operating a gasoline vehicle. Idaho National Laboratory (2005) "Comparing Energy Costs per Mile for Electric and Gasoline-Fueled Vehicles" Advanced Vehicle Testing Activity report at avt.inel.gov accessed 11 July 2006.
• The use of Battery Electric Vehicles eliminates the dependency on foreign oil.

Cons

• The energy used in electric vehicles needs to be derived from other sources.
• Current battery technology is expensive.
• Battery electric vehicles have a relative short range compared to internal combustion engine vehicles.

Hydrogen economy Hydrogen can be manufactured at roughly 77 percent thermal efficiency by the method of steam reforming of natural gas http://cta.ornl.gov/data/index.shtml. When manufactured by this method it is a derivative fuel like gasoline; when produced by electrolysis of water, it is a form of chemical energy storage as are storage battery (electricity), though hydrogen is the more versatile storage mode since there are two options for its conversion to useful work: (1) a fuel cell can convert the chemicals hydrogen and oxygen into water, and in the process, produce electricity, or (2) hydrogen can be burned (less efficiently than in a fuel cell) in an internal combustion engine.

Pros

• Hydrogen is colorless, odorless and entirely non-polluting, yielding pure water vapor (with minimal NOx) as exhaust when combusted in air. This eliminates the direct production of exhaust gases that lead to smog, and carbon dioxide emissions that enhance the effect of global warming.
• Hydrogen is the lightest chemical element and has the best energy-to-weight ratio of any fuel (not counting tank mass).
• Hydrogen can be produced anywhere; it can be produced domestically from the decomposition of water. Hydrogen can be produced from domestic sources and the price can be established within the country.
• Electrolysis combined with fuel-cell regeneration is more than 50% efficient.

Cons

• Other than some volcanic emanations, hydrogen does not exist in its pure form in the environment, because it reacts so strongly with oxygen and other elements.
• It is impossible to obtain hydrogen gas without expending energy in the process. There are three ways to manufacture hydrogen;
• By breaking down hydrocarbons — mainly methane. If oil or gases are used to provide this energy, fossil fuels are consumed, forming pollution and nullifying the value of using a fuel cell. It would be more efficient to use fossil fuel directly.
• By electrolysis from water — The process of splitting water into oxygen and hydrogen using electrolysis consumes large amounts of energy. It has been calculated that it takes 1.4 joules of electricity to produce 1 joule of hydrogen (Pimentel, 2002).
• By reacting water with a metal such as sodium, potassium, or boron. Chemical by-products would be sodium oxide, potassium oxide, and boron oxide. Processes exist which could recycle these elements back into their metal form for re-use with additional energy input, further eroding the EROEI.
• There is currently modest infrastructure for distribution (business) of hydrogen that is centrally produced,http://www.praxair.com/praxair.nsf/d63afe71c771b0d785256519006c5ea1/2a5df393598d7f3b85256baf000827be?OpenDocument&Highlight=2,hydrogen amounting to several hundred kilometers of pipeline. An alternative would be transmission of electricity over the existing electrical network to small-scale electrolyzers to support the widespread use of hydrogen as a fuel.
• Hydrogen is difficult to handle, store, and transport. It requires heavy, cumbersome tanks when stored as a gas, and complex insulating bottles if stored as a cryogenic liquid. If it is needed at a moderate temperature and pressure, a metal hydride absorber may be needed. The transportation of hydrogen is also a problem because hydrogen leaks effortlessly from containers.
• Some current fuel cell designs, such as proton exchange membrane fuel cells, use platinum as a catalyst. Widescale deployment of such fuel cells could place a strain on available platinum resources. Study: World May Run Out of Copper Reducing the platinum loading, per fuel cell stack, is the focus of R&D.
• Electrical power industry and battery electric vehicles are far more efficient for storage, transmission and use of energy for transportation, neglecting the energy conversion at the electric power plant. As with distributed production of hydrogen via electrolysis, battery electric vehicles could utilize the existing electricity grid until widespread use dictated an expansion of the grid.

Energy Storage Types

• Chemical

Some natural forms of energy are found in stable chemical compounds such as fossil fuels. Most systems of chemical energy storage result from Biology activity, which store energy in chemical bonds. Man-made forms of chemical energy storage include hydrogen fuel, battery (electricity) and explosives such as cordite and dynamite.

• Gravitational

Dams can be used to store energy, by using excess energy to pump water into the reservoir. When electrical energy is required, the process is reversed. The water then turns a turbine, generating electricity. Hydroelectric power is currently an important part of the world's energy supply, generating one-fifth of the world's electricity. :.

• Electrical capacitance

Electrical energy may be stored in capacitors. Capacitors are often used to produce high intensity releases of energy (such as a camera's flash).

• Mechanical

*Pressure: :Energy may also be stored pressure gases or alternatively in a vacuum. Compressed air, for example, may be used to operate vehicles and power tools. Large scale compressed air energy storage facilities are used to smooth out demands on electricity generation by providing energy during peak hours and storing energy during off-peak hours. Such systems save on expensive generating capacity since it only needs to meet average consumption rather than peak consumption. *Flywheels and springs

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