Portal:Energy
Main page | New articles & Tasks |
The Energy Portal Welcome to Wikipedia's Energy portal, your gateway to energy. This portal is aimed at giving you access to all energy related topics in all of its forms.
|
Page contents: Selected article • Selected image • Selected biography • Did you know? • General images • Quotations • Related portals • Wikiprojects • Major topics • Categories • Help • Associated Wikimedia |
Introduction
In physics, energy (from Ancient Greek ἐνέργεια (enérgeia) 'activity') is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat and light. Energy is a conserved quantity—the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The unit of measurement for energy in the International System of Units (SI) is the joule (J).
Common forms of energy include the kinetic energy of a moving object, the potential energy stored by an object (for instance due to its position in a field), the elastic energy stored in a solid object, chemical energy associated with chemical reactions, the radiant energy carried by electromagnetic radiation, and the internal energy contained within a thermodynamic system. All living organisms constantly take in and release energy.
Due to mass–energy equivalence, any object that has mass when stationary (called rest mass) also has an equivalent amount of energy whose form is called rest energy, and any additional energy (of any form) acquired by the object above that rest energy will increase the object's total mass just as it increases its total energy.
Human civilization requires energy to function, which it gets from energy resources such as fossil fuels, nuclear fuel, or renewable energy. The Earth's climate and ecosystems processes are driven by the energy the planet receives from the Sun (although a small amount is also contributed by geothermal energy). (Full article...)
Selected article
Nuclear (fission) power stations, provided 11% of the world's electricity in 2012, somewhat less than that generated by hydro-electric stations at 16%. Nuclear energy policy differs between countries, and some countries have no active nuclear power stations, or have phased them out. The first nuclear generated electricity, used to power four 200-watt light bulbs, was produced at the EBR-I reactor near Arco, Idaho, in 1951. This was followed in 1954 by the first grid-connected plant (in the USSR), and in 1956 by the first commercial plant (in the United Kingdom).
During the last decades of the 20th century, concerns about nuclear waste, nuclear accidents, radiation and nuclear proliferation led to an anti-nuclear movement. The 1979 Three Mile Island accident, the 1986 Chernobyl disaster, and the 2011 Fukushima disaster also played a part in stopping new plants in many countries, while the economics of nuclear generation and of nuclear decommissioning have also been factors. Despite this, some countries including China and India have continued to remain active in developing nuclear power, Germany will close its 19 nuclear plants by 2020, and is investing heavily in renewable energy commercialization instead.
Selected image
Photo credit: Johnson Space Center/NASA
Tropical cyclones feed on the heat released when moist air rises and the water vapor condenses.
Did you know?
- Buildings constructed to the German Passivhaus standard use 75% to 95% less energy for space heating and cooling than current new buildings in the United States?
- Crossing 4,000 km (2,500 miles), the Druzhba pipeline is the world's longest oil pipeline?
- Coal is ground to a powder before being burnt in fossil fuel power plants?
- Compact fluorescent lamps (pictured) use about 1/4 of the energy of normal incandescent light bulbs, and pay for themselves after about 500 hours of use?
- Nuclear power in France produces 78% of all the country's electricity - more than in any other nation?
- Positive lightning bolts are typically six to ten times more powerful than normal lightning — and aircraft are not designed to withstand them?
- Dark energy is a hypothetical form of energy which permeates all of space?
Selected biography
Born in Texas, Hubbert studied geology, mathematics, and physics at the University of Chicago. He pursued his Ph.D. while working for the Amerada Petroleum Company, then worked for the Shell Oil Company from 1943 until 1964. On leaving Shell he became a senior research geophysicist for the United States Geological Survey until retiring in 1976. Hubbert was also a professor at Stanford University and at UC Berkeley.
Hubbert is most well-known for his studies on the capacities of oil fields and natural gas reserves. He predicted that, for any given geographical area, the rate of petroleum production over time would resemble a bell curve. At the 1956 meeting of the American Petroleum Institute, Hubbert predicted that United States petroleum production would peak in the late 1960s or early 1970s. He became famous when his prediction came true in 1970.
In 1974, Hubbert projected that global oil production would peak in 1995 "if current trends continue". Various subsequent predictions have been made by others as trends have fluctuated in the intervening years. Hubbert's theory, and its implications for the world economy, remain controversial.
General images
Quotations
- "If we already have the Kyoto protocol, why invent another proposal and not just implement one that already exists? If a country is incapable of implementing the result of an international treaty that has established rules and regulations, it won't end up implementing those rules voluntarily."" – Luiz Inácio Lula da Silva, 2007
- "Climate change is a challenge China must cope with to realize sustainable development... Implementing a climate change containment policy may cost a fortune, but the cost will be even higher if we delay. Early action is imperative." – Ma Kai, 2007
- "The consequences of restricting the development of developing nations will be much more serious than the consequences of global warming." – Ma Kai, 2007
Related portals
WikiProjects
WikiProjects connected with energy:
Other WikiProjects that may be of interest:
Major topics
Major categories
National energy supply, use & conservation
National electricity sector
Politics, economics, environment
- Climate change
- Energy conservation
- Energy economics
- Energy crises
- Energy development
- Energy policy
- Peak oil
Energy sources
- Fuels
- Biofuels
- Fossil fuels
- Fusion power
- Nuclear technology
- Renewable energy
- Energy conversion
- Electric power
- Energy storage
Energy-related design
Scientific usage
Category browser
Help
Puzzled by energy?
Can't answer your question?
Don't understand the answer?
- Ask at the reference desk
- Read the Wikipedia help pages
For further ideas, to leave a comment, or to learn how you can help improve and update this portal, see the talk page.
Associated Wikimedia
The following Wikimedia Foundation sister projects provide more on this subject:
-
Commons
Free media repository -
Wikibooks
Free textbooks and manuals -
Wikidata
Free knowledge base -
Wikinews
Free-content news -
Wikiquote
Collection of quotations -
Wikisource
Free-content library -
Wikiversity
Free learning tools -
Wiktionary
Dictionary and thesaurus