# Portal:Energy

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.
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 Page contents: Introduction • Energy news • Selected article • Selected picture • Selected biography • Did you know? • Quotations • Related portals • Wikiprojects • Associated Wikimedia • Help

## Introduction

The Sun is the source of energy for most of life on Earth. It derives its energy mainly from nuclear fusion in its core, converting mass to energy as protons are combined to form helium. This energy is transported to the sun's surface then released into space mainly in the form of radiant (light) energy.

In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object. 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 SI unit of energy is the joule, which is the energy transferred to an object by the work of moving it a distance of 1 metre against a force of 1 newton.

Common forms of energy include the kinetic energy of a moving object, the potential energy stored by an object's position in a force field (gravitational, electric or magnetic), the elastic energy stored by stretching solid objects, the chemical energy released when a fuel burns, the radiant energy carried by light, and the thermal energy due to an object's temperature.

Mass and energy are closely related. 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. For example, after heating an object, its increase in energy could be measured as a small increase in mass, with a sensitive enough scale.

Living organisms require energy to stay alive, such as the energy humans get from food. Human civilization requires energy to function, which it gets from energy resources such as fossil fuels, nuclear fuel, or renewable energy. The processes of Earth's climate and ecosystem are driven by the radiant energy Earth receives from the sun and the geothermal energy contained within the earth.

## Selected article

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.

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## Selected image

Photo credit: From an image by Contributor
This waste-to-energy plant is one of several that provides district heating in Vienna.

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## Did you know?

• Golar Spirit (pictured) is the world's first floating storage and regasification vessel converted from a LNG carrier?
• The scientific-technical journal Oil Shale is the only journal in the world that focuses on oil shale as a main subject?
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## Selected biography

Marion King Hubbert (1903–1989) was a geophysicist who made several important contributions to geology and geophysics, most notably the Hubbert curve and Hubbert peak theory (or peak oil), with important political ramifications.

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.

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