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
Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. The energy extracted from water depends on the volume and on the difference in height between the source and the water's outflow. Pumped storage hydroelectricity schemes produce electricity to supply high peak demands by moving water between reservoirs at different elevations. They currently provide the only commercially important means of grid energy storage. At times of low electrical demand, excess generation capacity is used to pump water back into the higher reservoir, from where it can be released through the turbines at short notice. Less common types of hydroelectricity include run-of-the-river, waterwheels, and tidal power schemes.
A major advantage of hydroelectricity is the elimination of fuel costs and the associated carbon emissions although, in tropical regions, decaying plant material behind the dam can sometimes result in greater greenhouse gas emissions than a conventional power station. Other issues include the need to relocate people from areas to be flooded and disruption caused to aquatic ecosystems.
Selected image
Photo credit: From an image by Arnold Paul
Coal-fired power stations transform chemical energy into 36%-48% electricity and 52%-64% waste heat.
Did you know?
- If atmospheric greenhouse gas concentrations can be stabilized at 450 ppm, it is thought that there will be a 50% chance of avoiding dangerous climate change?
- The Itaipu hydroelectric power plant is currently the second largest power plant in the world, supplying over 90% of Paraguay's electricity, and 25% of Brazil's?
- Libya's Sirte Basin—which in some places lies more than 47 metres below sea level—contains roughly 80% of the country's known crude oil reserves?
- Approximately 95% of the electricity consumed by a normal incandescent light bulb (example pictured) is emitted as heat, rather than as visible light?
- Saudi Aramco is the largest oil corporation in the world and the world's largest in terms of proven crude oil reserves and production?
- Newcastle, Australia, is the world's largest coal export port?
- Surplus income from oil production in Norway is invested by the Government Pension Fund, one of the World's largest funds with a value of around US$ 800 billion?
- Energy superpowers Russia and Venezuela have, respectively, the world's largest reserves of natural gas and petroleum?
Selected biography
Edison invented the first commercially practical electric light bulb which, by 1879 would burn for hundreds of hours. He was able to sell the concept to homes and businesses by mass-producing them and creating a complete system for the generation and distribution of electricity.
Edison patented an electric distribution system in 1880, and in January 1882 he switched on the first steam generating power station at Holborn Viaduct in London, UK. The direct current (DC) supply system provided electricity supplies to street lamps and a number of private dwellings within a short distance of the station. The first investor-owned electric utility, Pearl Street Station, New York City, started generating on September 4, 1882, providing 110 volts direct current to 59 customers in lower Manhattan.
Life magazine (USA), in a special double issue, placed Edison first in the list of the "100 Most Important People in the Last 1000 Years," noting that the light bulb he promoted "lit up the world." He was ranked thirty-fifth on Michael H. Hart's list of the most influential figures in history.
In the news
- 1 June 2024 – Russian invasion of Ukraine
- Russia launches missile and drone strikes across Ukraine, injuring at least four people and damaging critical infrastructure, including energy facilities. Ukraine says that it shot down 35 of 53 missiles and 46 of 47 drones. (Reuters)
General images
Quotations
- "We simply must balance our demand for energy with our rapidly shrinking resources. By acting now we can control our future instead of letting the future control us." – Jimmy Carter, 1977
- "It is sensible to improve energy efficiency and to develop alternative and sustainable sources of supply; it's sensible to replant the forests which we consume; it's sensible to re-examine industrial processes; it's sensible to tackle the problem of waste. I understand that the latest vogue is to call them 'no regrets' policies. Certainly we should have none in putting them into effect." – Margaret Thatcher, 1990
- "We have the opportunity and potential to create an oil-free future today, it is potentially right around the corner - and, more often than not, the technology is already here." – John Kerry, 2003
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