Photo credit: NASA/TRACE
Plasma being channeled by the magnetic field loops of a sunspot.

Photo credit: Charliebrown7034
Skyglow over New York City, one form of light pollution.

Photo credit: United States Department of Energy
The fireball created as energy is released in a nuclear explosion.

Photo credit: Luc Lviatour
Electricity ionizing the gas in a plasma lamp.

Photo credit: Postdlf
Lightning is a highly visible form of energy transfer.

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

Photo credit: Senior Airman Joshua Strang, United States Air Force
An aurora, caused by the release of energy as charged particles collide with atoms in the Earth's upper atmosphere.

Photo credit: Johnson Space Center/NASA
Tropical cyclones feed on the heat released when moist air rises and the water vapor condenses.

Photo credit: From an image by Wolfgang Beyer
Strombolian volcanic eruptions can eject incandescent cinder, lapilli and lava bombs to altitudes of tens to hundreds of meters.

Photo credit: From an image by Arnold Paul
Coal-fired power stations transform chemical energy into 36%-48% electricity and 52%-64% waste heat.

Photo credit: Andreas Tille
Geysers erupt periodically due to surface water being heated by geothermal heat.

Photo credit: Björn Appel
A solar furnace can be used to generate electricity, melt steel or make hydrogen fuel.

Photo credit: Stephen Codrington
Wood is an important fuel in many developing countries.

Photo credit: Flickr
The 11 MW PS10 solar power tower near Seville in Spain.

Photo credit: United States Department of Agriculture
Fire is a rapid oxidation process that creates heat and light, together with smoke and other products of combustion.

Photo credit: Jon Sullivan
Photosynthesis is a complex energy transformation process in which sunlight, carbon dioxide and water are converted to chemical energy by living organisms.

Photo credit: United States Air Force
The IPCC estimates that aviation will account for 4% of all carbon emissions released by human activity by 2050.

Photo credit: User:Minesweeper
The use of fuels for transport accounts for around 14% of world greenhouse gas emissions, but over 25% of emissions in some countries.

Photo credit: Cooldude110
Pipeline transport is the transportation of goods through a pipe, most commonly liquid and gases such as crude oil and natural gas.

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

Photo credit: From an image by Jonas Jordan, USACE
Oil wells in Kuwait were set alight by retreating Iraqi forces during the 1991 Gulf War.

Photo credit: From an image by Grétar Ívarsson
Geothermal power, the harnessing of geothermal heat to generate electricity, is used in over 20 countries.

Photo credit:
During the 2011 Fukushima nuclear emergency in Japan, three nuclear reactors were damaged by explosions.

Photo credit: Greenpeace
Oil shale is a source of unconventional oil, which combustion and thermal processing generate atmospheric emissions. Pictured is oil shale being mined by the Viru Keemia Grupp.

Photo credit: BDS2006
Wind farm is a group of wind turbines in the same location used for production of electric power.

Photo credit: A. Lepik
Wind power is the conversion of wind energy into useful form, such as electricity, using wind turbines.

Photo credit: George Louis
Electric power transmission is the bulk transfer of electrical energy, a process in the delivery of electricity to consumers

Photo credit: Diliff
An electrical grid is an interconnected network for delivering electricity from generation facilities such as wind farms to consumers.

Photo credit: Diliff
The Empire State Building is being transformed into a more energy efficient and eco-friendly structure, at a cost of $120 million.

Photo credit: kallerna
Andasol Solar Power Station is a 150-megawatt (MW) concentrated solar power station and Europe's first commercial plant to use parabolic troughs.