Sources of Energy

Renewable EnergyA clean energy revolution is taking place across America, underscored by the steady expansion of the U.S. renewable energy sector.The clean energy industry generates hundreds of billions in economic activity, and is expected to continue to grow rapidly in the coming years. There is tremendous economic opportunity for the countries that invent, manufacture and export clean energy technologies. Responsible development of all of America’s rich energy resources -- including solar, wind, geothermal,

bioenergy and water -- is an important part of President Obama’s Climate Action Plan and will help ensure America’s continued leadership in clean energy. Moving forward, the Energy Department will continue to drive strategic investments in the transition to a cleaner, domestic and more secure energy future.

Renewable energy is energy generated from natural resources—such as sunlight, wind, rain, tides and geothermal heat—which are renewable (naturally replenished). Renewable energy technologies range from solar power, wind power, hydroelectricity/micro hydro, biomass and biofuels for transportation. Renewable energy is energy that is generated from natural processes that are continuously replenished. This includes sunlight, geothermal heat, wind, tides, water, and various forms of biomass. This energy cannot be exhausted and is constantly renewed.Alternative energy is a term used for an energy source that is an alternative to using fossil fuels. Generally, it indicates energies that are non-traditional and have low environmental impact. The term alternative is used to contrast with fossil fuels according to some sources. By most definitions alternative energy doesn't harm the environment, a distinction which separates it from renewable energy which may or may not have significant environmental impact.What is Biomass?Biomass, is a renewable organic matter, and can include biological material derived from living, or recently living organisms, such as wood, waste, and alcohol fuels.Wood energy is derived both from harvested wood as a fuel and from wood waste products. Waste energy can be generated from municipal waste, manufacturing waste, and landfill gas. Biomass alcohol fuel, or ethanol, is derived almost exclusively from corn.What is Biodiesel?Biodiesel is fuel made from plant oils that can be used in diesel engines. They are typically made of renewable organic raw materials such as soybean or rapeseed oils, animal fats, waste vegetable oils or microalgae oils.

Nuclear power is the use of nuclear reactions that release nuclear energy[5] to generate heat, which most frequently is then used in steam turbines to produce electricity in a nuclear power plant. The term includes nuclear fission, nuclear decay and nuclear fusion. Presently, the nuclear fission of elements in the actinide series of the periodic table produce the vast majority of nuclear energy in the direct service of humankind, with nuclear decay processes, primarily in the form of geothermal energy, and radioisotope thermoelectric generators, in niche uses making up the rest.

Fission-electric power stations are one of the leading low carbon power generation methods of producing electricity, and in terms of total life-cycle greenhouse gas emissions per unit of energy generated, has emission values lower than "renewable energy" when the latter is taken as a single energy source.[6][7] Since all electricity supplying technologies use cement, etc., during construction, emissions are yet to be brought to zero. A 2014 analysis of the carbon footprint literature by the Intergovernmental Panel on Climate Change (IPCC) reported that the embodied total life-cycle emission intensity of fission electricity has a median value of 12 g CO2 eq/kWh which is the lowest out of all commercial baseload energy sources,[8][9] and second lowest out of all commercial electricity technologies known, after wind power which is an Intermittent energy source with embodied greenhouse gas emissions, per unit of energy generated of 11 g CO2eq/kWh. Each result is contrasted with coal & fossil gas at 820 and 490 g CO2 eq/kWh.[8][9] With this translating into, from the beginning of Fission-electric power station commercialization in the 1970s, having prevented the emission of about 64 billion tonnes of carbon dioxide equivalent, greenhouse gases that would have otherwise resulted from the burning of fossil fuels in thermal power stations.[10]

There is a social debate about nuclear power.[11][12][13] Proponents, such as the World Nuclear Association and Environmentalists for Nuclear Energy, contend that nuclear power is a safe, sustainable energy source that reduces carbon emissions.[14] Opponents, such as Greenpeace International and NIRS, contend that nuclear power poses many threats to people and the environment.[15][16][17]

Far-reaching fission power reactor accidents, or accidents that resulted in medium to long-lived fission product contamination of inhabited areas, have occurred in Generation I & II reactor designs, blueprinted between 1950 and 1980. These include the Chernobyl disaster which occurred in 1986, the Fukushima Daiichi nuclear disaster (2011), and the more contained Three Mile Island accident (1979).[18] There have also been some nuclear submarine accidents. [18][19][20] In terms of lives lost per unit of energy generated, analysis has determined that fission-electric reactors have caused fewer fatalities per unit of energy generated than the other major sources of energy generation. Energy production from coal, petroleum, natural gas and hydroelectricity has caused a greater number of fatalities per unit of energy generated due to air pollution and energy accident effects.[21][22][23][24][25][26] Four years after the Fukushima-Daiichi accident, there have been no fatalities due to exposure to radiation, and no discernible increased incidence of radiation-related health effects are expected among exposed members of the public and their descendants. [27] The Japan Times estimated 1,600 deaths were the result of evacuation, due to physical and mental stress stemming from long stays at shelters, a lack of initial care as a result of hospitals being disabled by the tsunami, and suicides.[28]

In 2015:[29]

Ten new reactors were connected to the grid. Seven reactors were permanently shut down. 441 reactors had a worldwide net capacity of 382,855 megawatts of electricity. 67 new nuclear reactors were under construction.

Most of the new activity is in China where there is an urgent need to control pollution from coal plants.[30]

In October 2016, Watts Bar 2 became the first new United States reactor to enter commercial operation since 1996.

Electrical energy is the energy newly derived from electric potential energy or kinetic energy. When loosely used to describe energy absorbed or delivered by an electrical circuit (for example, one provided by an electric power utility) "electrical energy" talks about energy which has been converted from electric potential energy. This energy is supplied by the combination of electric current and electric potential that is delivered by the circuit. At the point that this electric potential energy has been converted to another type of energy, it ceases to be electric potential energy.

Thus, all electrical energy is potential energy before it is delivered to the end-use. Once converted from potential energy, electrical energy can always be called another type of energy (heat, light, motion, etc.).Electricity generationElectricity generation is the process of generating electrical energy from other forms of energy.

The fundamental principle of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday. His basic method is still used today: electricity is generated by the movement of a loop of wire, or disc of copper between the poles of a magnet.[1]

For electric utilities, it is the first step in the delivery of electricity to consumers. The other processes, electricity transmission, distribution, and electrical power storage and recovery using pumped-storage methods are normally carried out by the electric power industry.[2]

Electricity is most often generated at a power station by electromechanical generators, primarily driven by heat engines fueled by chemical combustion or nuclear fission but also by other means such as the kinetic energy of flowing water and wind. There are many other technologies that can be and are used to generate electricity such as solar photovoltaics and geothermal power.

Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms, containing energy originating in ancient photosynthesis.[1] The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years.[2] Fossil fuels contain high percentages of carbon and include petroleum, coal,

and natural gas.[3] Other commonly used derivatives include kerosene and propane. Fossil fuels range from volatile materials with low carbon:hydrogen ratios like methane, to liquids like petroleum, to nonvolatile materials composed of almost pure carbon, like anthracite coal. Methane can be found in hydrocarbon fields either alone, associated with oil, or in the form of methane clathrates.The theory that fossil fuels formed from the fossilized remains of dead plants[4] by exposure to heat and pressure in the Earth's crust over millions of years[5] was first introduced by Georgius Agricola in 1556 and later by Mikhail Lomonosov in the 18th century.The Energy Information Administration estimates that in 2007 the primary sources of energy consisted of petroleum 36.0%, coal 27.4%, natural gas 23.0%, amounting to an 86.4% share for fossil fuels in primary energy consumption in the world.[6] Non-fossil sources in 2006 included nuclear 8.5%, hydroelectric 6.3%, and others (geothermal, solar, tidal, wind, wood, waste) amounting to 0.9%.[7] World energy consumption was growing about 2.3% per year.Although fossil fuels are continually being formed via natural processes, they are generally considered to be non-renewable resources because they take millions of years to form and the known viable reserves are being depleted much faster than new ones are being made.[citation needed]

The use of fossil fuels raises serious environmental concerns. The burning of fossil fuels produces around 21.3 billion tonnes (21.3 gigatonnes) of carbon dioxide (CO2) per year, but it is estimated that natural processes can only absorb about half of that amount, so there is a net increase of 10.65 billion tonnes of atmospheric carbon dioxide per year (one tonne of atmospheric carbon is equivalent to 44/12 or 3.7 tonnes of carbon dioxide).[8] Carbon dioxide is one of the greenhouse gases that enhances radiative forcing and contributes to global warming, causing the average surface temperature of the Earth to rise in response, which the vast majority of climate scientists agree will cause major adverse effects. A global movement towards the generation of renewable energy is therefore under way to help reduce global greenhouse gas emissions.