Portal:Energy

Portal topics: Activities; Culture; Geography; Health; History; Mathematics; Nature; People; Philosophy; Religion; Society; Technology; Random portal

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

A plasma globe, using electrical energy to create plasma, light, heat, movement and a faint sound

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...)

Refresh with new selections below (purge)

edit

Selected article

World primary energy consumption 1998-1999

In 2004, the worldwide energy consumption of the human race was on average 15 terawatts (TW; 1 TW = 1 x 10¹² W) with 86.5% from burning fossil fuels. This is equivalent to 471,000 PJ (1 PJ = 1 x 10¹⁵ J) per year. There is at least 10% uncertainty in these figures due to national variations in tracking consumption, and due to variations in energy content between particular barrels of oil or tons of coal.

The remaining worldwide energy resources are large, with the remaining fossil fuels totaling an estimated 0.4 YJ (1 YJ = 10²⁴ J) and the available nuclear fuel such as uranium exceeding 2.5 YJ (1 YJ = 10²⁴ J). Mostly thanks to the Sun, the world also has a renewable usable energy flux that exceeds 120 PW (8,000 times 2004 total energy usage), or 3.8 YJ/yr, dwarfing all non-renewable resources.

Despite the abundance of fossil fuels there are a number of pressures that may move the world’s energy consumption to alternative energy sources. These include political considerations over energy security and potential pressure from energy superpowers, environmental concerns related to global warming and sustainability, and economic pressure resulting from energy price rises, carbon emissions trading and green taxation.

This move is already starting to happen in some countries, notably as a result of the Kyoto Protocol, and further steps in this direction are proposed. For example, the European Commission has proposed that the energy policy of the European Union should set a binding target of increasing the maximum level of renewable energy in the EU’s overall mix from less than 7% today to 20% by 2020.

More selected articles

More...

edit

Selected image

Photo credit: NASA
A Saturn V rocket launches Apollo 11, burning 3,580 U.S. gallons (13,552 liters) of kerosene per second.

More selected pictures

edit

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?

Estonia generates more than 90% of its electrical power from oil shale?

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?

More Did you know facts

edit

Selected biography

James E. Hansen (born March 29, 1941) heads the NASA Institute for Space Studies and is currently an adjunct professor in the Earth and Environmental Sciences department at Columbia University. He is best known for his testimony on climate change to congressional committees in the 1980s that helped raise broad awareness of global warming.

Hansen studied at the University of Iowa, obtaining a B.A. in Physics and Mathematics, an M.S. in Astronomy and a Ph.D. in Physics. He was elected to the National Academy of Sciences in 1996 and received the Heinz Environment Award for his research on global warming in 2001.

Hansen is a vocal critic of the Bush Administration's ideology on climate change. In 2005 and 2006, he claimed that NASA administrators have tried to influence his public statements about the causes of climate change. He has also claimed that the White House edited climate-related press releases from federal agencies to make global warming seem less threatening, and that he is unable to speak 'freely', without the backlash of other government officials.

Hansen has said that a global tipping point will be reached by 2016 if levels of greenhouse gases are not reduced. After this point global warming becomes unstoppable. As a result he claims that there may be a rise in sea levels by as much as 10 feet (3 metres) by 2100.

Introduction

Selected article

Selected image

Did you know?

Selected biography

In the news

General images