Energy development is the field of activities focused on obtaining sources of energy from natural resources. These activities include the production of fossil fuel-derived, nuclear, and renewable sources of energy, and for the recovery and reuse of energy that would otherwise be wasted. Energy conservation and efficiency measures reduce the demand for energy development and can benefit society by improving environmental issues.
Societies use energy for communication, heating, ventilation, and air conditioning, illumination, manufacturing, and transportation, for agricultural, commercial, domestic, and industrial purposes. Energy resources may be classified as primary resources, where the resource can be used in substantially its original form, or as secondary resources, where the energy source must be converted into a more conveniently usable form. Non-renewable resources are significantly depleted by human use, whereas renewable resources are produced by ongoing processes that can sustain indefinite human exploitation.
Thousands of people are employed in the energy industry. The conventional industry comprises the petroleum industry, the natural gas industry, the electrical power industry, and the nuclear industry. New energy industries include the renewable energy industry, comprising alternative and sustainable manufacture, distribution, and sale of alternative fuels.
Classification of resources
Energy resources may be classified as primary resources, suitable for end use without conversion to another form, or secondary resources, where the usable form of energy requires substantial conversion from a primary source. Examples of primary energy resources are wind power, solar power, wood fuel, fossil fuels such as coal, oil and natural gas, and uranium. Secondary resources are those such as electricity, hydrogen, and other synthetic fuels.
Another important classification is based on the time required to regenerate an energy resource. "Renewable resources" are those that recover their capacity in a time significant by human needs. Examples include hydroelectric power or wind power, when the natural phenomena that are the primary source of energy are ongoing and not depleted by human demand. Non-renewable resources are those that are significantly depleted by human usage and that will not recover their potential significantly during human lifetimes. An example of a non-renewable energy source is coal, which does not form naturally at a rate that would support human use.
Fossil fuels
Fossil fuel (primary non-renewable fossil) sources burn coal or hydrocarbon fuels, which are the remains of the decomposition of plants and animals. There are three main types of fossil fuels: coal, petroleum, and natural gas. Another fossil fuel, liquefied petroleum gas (LPG), is principally derived from the production of natural gas. Heat from burning fossil fuel is used either directly for space heating and process heating or converted to mechanical energy for vehicles, industrial processes, or electrical power generation. These fossil fuels are part of the carbon cycle and allow solar energy stored in the fuel to be released.
The use of fossil fuels in the 18th and 19th centuries set the stage for the Industrial Revolution.
Fossil fuels make up the bulk of the world's current primary energy sources. In 2024, 86% of the world's energy needs were met from fossil fuels, up from 81% in 2005.International Energy Agency: Key World Energy Statistics 2007. S. 6 The technology and infrastructure for the use of fossil fuels already exist. Liquid fuels derived from petroleum deliver much usable energy per unit of weight or volume, which is advantageous when compared with lower energy density sources such as batteries. Fossil fuels are currently economical for decentralized energy use.
Energy dependence on imported fossil fuels creates energy security risks for dependent countries.Energy Security and Climate Policy: Assessing Interactions. p125Energy Security: Economics, Politics, Strategies, and Implications. Edited by Carlos Pascual, Jonathan Elkind. p210Geothermal Energy Resources for Developing Countries. By D. Chandrasekharam, J. Bundschuh. p91Congressional Record, V. 153, PT. 2, January 18, 2007 to February 1, 2007 edited by U S Congress, Congress (U.S.). p 1618India s Energy Security. Edited by Ligia Noronha, Anant Sudarshan. Oil dependence in particular has led to war,National security, safety, technology, and employment implications of increasing CAFE standards : hearing before the Committee on Commerce, Science, and Transportation, United States Senate, One Hundred Seventh Congress, second session, January 24, 2002. DIANE Publishing. p10 funding of radicals,Ending our-Dependence on Oil - American Security Project. americansecurityproject.org monopolization,Energy Dependency, Politics and Corruption in the Former Soviet Union. By Margarita M. Balmaceda. Psychology Press, December 6, 2007. and socio-political instability.Oil-Led Development : Social, Political, and Economic Consequences. Terry Lynn Karl. Stanford University. Stanford, California, United States.
Fossil fuels are non-renewable resources, which will eventually decline in production Peaking of World Oil Production: Impacts, Mitigation, and Risk Management. Was at: www.pppl.gov/polImage.cfm?doc_Id=44&size_code=Doc and become exhausted. While the processes that created fossil fuels are ongoing, fuels are consumed far more quickly than the natural replenishment rate. Extracting fuels becomes increasingly costly as society consumes the most accessible fuel deposits. Extraction of fossil fuels results in environmental degradation, such as the strip mining and mountaintop removal for coal.
Fuel efficiency is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work. The fuel economy is the energy efficiency of a particular vehicle and is given as a ratio of distance travelled per unit of fuel consumed. Weight-specific efficiency (efficiency per unit weight) may be stated for freight, and passenger-specific efficiency (vehicle efficiency) per passenger. The inefficient atmospheric combustion (burning) of fossil fuels in vehicles, buildings, and power plants contributes to urban heat islands.
Conventional production of oil peaked, conservatively, between 2007 and 2010. In 2010, it was estimated that an investment of $8 trillion in non-renewable resources would be required to maintain current levels of production for 25 years. In 2010, governments subsidized fossil fuels by an estimated $500 billion a year.ScienceDaily.com (April 22, 2010) "Fossil-Fuel Subsidies Hurting Global Environment, Security, Study Finds" Fossil fuels are also a source of greenhouse gas emissions, leading to concerns about global warming if consumption is not reduced.
The combustion of fossil fuels leads to the release of pollution into the atmosphere. The fossil fuels are mainly carbon compounds. During combustion, carbon dioxide is released, and also nitrogen oxides, soot and other fine particulates. The carbon dioxide is the main contributor to recent climate change.Intergovernmental Panel on Climate Change (2007): IPCC Fourth Assessment Report - Working Group I Report on "The Physical Science Basis". Other emissions from fossil fuel power station include sulphur dioxide, carbon monoxide (CO), hydrocarbons, volatile organic compounds (VOC), mercury, arsenic, lead, cadmium, and other heavy metals including traces of uranium.NRDC: There Is No Such Thing as "Clean Coal"
A typical coal plant generates billions of kilowatt-hours of electrical power per year.How much electricity does a typical nuclear power plant generate ? - FAQ - U.S. Energy Information Administration (EIA)
Nuclear Fission
Nuclear power is the use of nuclear fission to generate useful heat and electricity. Fission of uranium produces nearly all economically significant nuclear power. Radioisotope thermoelectric generators form a very small component of energy generation, mostly in specialized applications such as deep-space vehicles.
Nuclear power plants, excluding naval reactors, provided about 5.7% of the world's energy and 13% of the world's electricity in 2012.
In 2013, the IAEA report that there are 437 operational nuclear power reactors, in 31 countries, although not every reactor is producing electricity. In addition, there are approximately 140 naval vessels using nuclear propulsion in operation, powered by some 180 reactors. Naval Nuclear Propulsion, Magdi Ragheb. As of 2001, about 235 naval reactors had been built As of 2013, attaining a net energy gain from sustained nuclear fusion reactions, excluding natural fusion power sources such as the Sun, remains an ongoing area of international physics and engineering research. More than 60 years after the first attempts, commercial fusion power production remains unlikely before 2050. - Projected fusion power timeline
There is an ongoing debate about nuclear power.James J. MacKenzie. Review of The Nuclear Power Controversy by Arthur W. Murphy The Quarterly Review of Biology, Vol. 52, No. 4 (Dec., 1977), pp. 467-468.In February 2010 the nuclear power debate played out on the pages of The New York Times, see A Reasonable Bet on Nuclear Power and Revisiting Nuclear Power: A Debate and A Comeback for Nuclear Power? Proponents, such as the World Nuclear Association, the IAEA and Environmentalists for Nuclear Energy contend that nuclear power is a safe, sustainable energy source that reduces carbon emissions.U.S. Energy Legislation May Be 'Renaissance' for Nuclear Power . Opponents contend that nuclear power poses many threats to people and the environment.
Nuclear power plant accidents include the Chernobyl disaster (1986), Fukushima Daiichi nuclear disaster (2011), and the Three Mile Island accident (1979). There have also been some nuclear submarine accidents.Strengthening the Safety of Radiation Sources p. 14. In terms of lives lost per unit of energy generated, analysis has determined that nuclear power has caused less fatalities per unit of energy generated than the other major sources of energy generation. Energy production from coal, petroleum, natural gas and hydropower has caused a greater number of fatalities per unit of energy generated due to air pollution and energy accident effects. with Chernobyl's total predicted linear no-threshold cancer deaths included, nuclear power is safer when compared to many alternative energy sources' immediate, death rate. Comparing Nuclear's latent cancer deaths, such as cancer with other energy sources immediate deaths per unit of energy generated(GWeyr). This study does not include fossil fuel-related cancer and other indirect deaths created by the use of fossil fuel consumption in its "severe accident" classification, an accident with more than 5 fatalities. However, the economic costs of nuclear power accidents is high, and meltdowns can take decades to clean up. The human costs of evacuations of affected populations and lost livelihoods is also significant.
Comparing Nuclear's latent cancer deaths, such as cancer with other energy sources' immediate deaths per unit of energy generated(GWeyr). This study does not include fossil fuel-related cancer and other indirect deaths created by the use of fossil fuel consumption in its "severe accident" classification, which would be an accident with more than 5 fatalities.