Future energy development

From Wikipedia, the free encyclopedia

It has been suggested that this article or section be merged into energy development. (Discuss)

Future energy development, providing for the world's future energy needs, currently faces great challenges. These include an increasing world population, demands for higher standards of living, a need for less pollution, a need to avert global warming, and a possible end to fossil fuels (see Hubbert peak theory). Without energy, the world's entire industrialized infrastructure would collapse; agriculture, transportation, waste collection, information technology, communications and much of the prerequisites that a developed nation takes for granted. A shortage of the energy needed to sustain this infrastructure could lead to a Malthusian catastrophe.

Energy Portal

[edit] General considerations

Main article: Energy development

Almost all forms of terrestrial energy, such as fossil fuels, solar, wind, ocean thermal, and hydropower, can be traced back to energy received from the sun's fusion reactions. The only exceptions are tidal, nuclear, and geothermal power. Tidal energy comes from the gravitational potential energy of the Earth/Moon system. Geothermal energy is believed to be generated primarily by radioactive decay inside the Earth.^[1]

Most human energy sources today use energy from sunlight, in the form of fossil fuels (coal, oil and gas). Once the stored forms are used up (assuming no contribution from the three previous energy sources and no energy from space exploration) then the long-term energy usage of humanity is limited to that from the sunlight falling on Earth. The total energy consumption of humanity today is equivalent to about 0.1-0.01 percent of that. Covering a vast area like the Gobi Desert with solar power generation would provide the total current world energy usage.^{[2] [3]}

U.S. energy consumption by sectors.

World energy production by source in 2004: Oil 40%, coal 23.3%, natural gas 22.5%, hydroelectric 7.0%, nuclear 6.5%, biomass and other 0.7%.^[4] In the U.S., transportation accounted for 28% of all energy use and 70% of petroleum use in 2001; 97% of transportation fuel was petroleum.^[5]

The United Nations projects that world population will stabilize in 2075 at nine billion due to the demographic transition. Birth rates are now falling in most developing nations and the population would decrease in several developed nations if there was no immigration.^[6] Since 1970, each 1 percent increase in the gross world product has yielded a 0.64 percent increase in energy consumption.^[7]

In geology, resources refer to the amount of a specific substance that may be present in a deposit. This definition does not take into account the economic feasibility of exploitation or the fact that resources may not be recoverable using current or future technology. Reserves constitute those resources that are recoverable using current technology. They can be recovered economically under current market conditions. This definition takes into account current mining technology and the economics of recovery, including mining and transport costs, government royalties and current market prices. Reserves decrease when prices are too low for some of the substance to be recovered economically, and increase when higher prices make more of the substance economically recoverable. Neither of these terms consider the energy required for exploitation (except as reflected in economic costs) or whether there is a net energy gain or loss.

Energy production usually requires an energy investment. Drilling for oil or building a wind power plant requires energy. The fossil fuel resources (see above) that are left are often increasingly difficult to extract and convert. They may thus require increasingly higher energy investments. If the investment is greater than the energy produced, then the fossil resource is no longer an energy source. This means that a large part of the fossil fuel resources and especially the non-conventional ones cannot be used for energy production today. Such resources may still be exploited economically in order to produce raw materials for plastics, fertilizers or even transportation fuel but now more energy is consumed than produced. (They then become similar to ordinary mining reserves, economically recoverable but not net positive energy sources.) New technology may ameliorate this problem if it can lower the energy investment required to extract and convert the resources, although ultimately basic physics sets limits that cannot be exceeded.

The classification of energy sources into renewables and non-renewables is not without problems. Geothermal power and hydroelectric power are classified as renewable energy but geothermal sites eventually cool down and hydroelectric dams gradually become filled with silt, which may be very expensive to remove. Although it can be argued that while a specific location may be depleted, the total amount of potential geothermal and hydroelectric power is not and a new power plant may sometimes be built on a different location. Nuclear power is not classified as a renewable but the amount of uranium in the seas may continue to be replenished by rivers through erosion of underground resources for as long as the remaining life of the Sun. Fossil fuels are finite but hydrocarbon fuel may be produced in several ways as described below.

Many of the current or potential future power production numbers given below do not subtract the energy consumed due to loss of energy from constructing the power facilities and distribution network, energy distribution itself, maintenance, inevitable replacement of old power production facilities and distribution network, backup capacity due to intermittent output, and energy required to reverse damage to the environment and other externalities. Net power production using life cycle analysis is more correct but more difficult and has many new uncertain factors.

[edit] History of predictions about future energy development

Ever since the beginning of the Industrial Revolution, the question of the future of energy supplies has occupied economists.

• 1865 - William Stanley Jevons published The Coal Question in which he claimed that reserves of coal would soon be exhausted and that there was no prospect of oil being an effective replacement.
• 1885 - U.S. Geological Survey: Little or no chance of oil in California.
• 1891 - U.S. Geological Survey: Little or no chance of oil in Kansas or Texas.
• 1914 - U.S. Bureau of Mines: Total future production of 5.7 billion barrels.
• 1939 - U.S. Department of the Interior: Reserves to last only 13 years.
• 1951 - U.S. Department of the Interior, Oil and Gas Division: Reserves to last 13 years.

(Data from Kahn et al. (1976) pp.94-5 infra)

• 1956 - Geophysicist M. King Hubbert predicts U.S. oil production will peak between 1965 and 1970 (peaked in 1971). Also predicts world oil production will peak "within half a century" based on 1956 data. This is Hubbert peak theory.
• 1989 - Predicted peak by Colin Campbell ("Oil Price Leap in the Early Nineties," Noroil, December 1989, pages 35-38.)
• 2004 - OPEC estimates it will nearly double oil output by 2025 (Opec Oil Outlook to 2025 Table 4, Page 12)

The history of perpetual motion machines is a long list of failed and sometimes fraudulent inventions of machines which produce useful energy "from nowhere" - that is, without requiring additional energy input.

[edit] Sustainable Energy

[edit] Nuclear power

Higher electricity use per capita correlates with a higher score on the Human Development Index(1997). Developing nations score much lower on these variables than developed nations. The continued rapid economic growth and increase in living standards in developing nations with large populations, like China and India, is dependent on a rapid and large expansion of energy production capacity.

Developing nations also use less total energy per capita. FSU/EE stands for Former Soviet Union and Eastern Europe. Source: EIA.

Developing nations use their energy less efficiently than developed nation, getting less GDP for the same amount of energy. One important cause is old technology. Notable is the very low energy efficiency in the former communist states. Source: EIA.

An increasing share of world energy consumption is predicted to be used by developing nations. Source: EIA.

Main article: Nuclear power

Depending on the type of fission fuel considered, estimates for existing supply at known usage rates varies from thousands of years for uranium-238 to several decades for the currently popular Uranium-235. At the present use rate, there are (as of 2007) about 70 years left of known uranium-235 reserves economically recoverable at an uranium price of US$ 130/kg.^[8] The nuclear industry argue that the cost of fuel is a minor cost factor for fission power, more expensive, more difficult to extract sources of uranium could be used in the future, such as lower-grade ores, and if prices increased enough, from sources such as granite and seawater.^[9] Increasing the price of uranium would have little effect on the overall cost of nuclear power; a doubling in the cost of natural uranium would increase the total cost of nuclear power by 5 percent. On the other hand, if the price of natural gas was doubled, the cost of gas-fired power would increase by about 60 percent.^[10] Another alternative would be to use thorium as fission fuel. Thorium is three times more abundant in Earth's crust than uranium,^[11] and much more of the thorium can be used (or, more precisely, converted into Uranium-233 and then used).

Current light water reactors burn the nuclear fuel poorly, leading to energy waste. Nuclear reprocessing ^[12] or burning the fuel better using different reactor designs would reduce the amount of waste material generated and allow better use of the available resources. As opposed to current light water reactors which use uranium-235 (0.7 percent of all natural uranium), fast breeder reactors convert the more abundant uranium-238 (99.3 percent of all natural uranium) into plutonium for fuel. It has been estimated that there is anywhere from 10,000 to five billion years worth of Uranium-238 for use in these power plants^[13] . Breeder technology has been used in several reactors. However, the breeder reactor at Dounreay in Scotland, Monju in Japan and the Superphénix at Creys-Malville in France, in particular, have all had difficulties and were not economically competitive and have been decommissioned. The People's Republic of China intends to build breeders.^[14]

The possibility of nuclear meltdowns and other reactor accidents, such as the Three Mile Island accident and the Chernobyl disaster, have caused much public fear. Research is being done to lessen the known problems of current reactor technology by developing automated and passively-safe reactors. Historically, however, coal and hydropower power generation have both been the cause of more deaths per energy unit produced than nuclear power generation.^{[15] [16]} Various kinds of energy infrastructure might be attacked by terrorists, including nuclear power plants, hydropower plants, and liquified natural gas tankers. Nuclear proliferation is the spread from nation to nation of nuclear technology, including nuclear power plants but especially nuclear weapons. New technology like SSTAR ("small, sealed, transportable, autonomous reactor") may lessen this risk.

The long-term radioactive waste storage problems of nuclear power have not been fully solved. Several countries have considered using underground repositories. Nuclear waste takes up little space compared to wastes from the chemical industry which remain toxic indefinitely.^[17] Spent fuel rods are now stored in concrete casks close to the nuclear reactors.^[18] The amounts of waste can be reduced in several ways. Both nuclear reprocessing and fast breeder reactors can reduce the amounts of waste. Subcritical reactors or fusion reactors could greatly reduce the time the waste has to be stored.^[19] Subcritical reactors may also be able to do the same to already existing waste.

The economics of nuclear power is not simple to evaluate, because of high capital costs for building and very low fuel costs. Comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear plants. See Economics of new nuclear power plants.

Depending on the source different energy return on energy investment (EROI) are claimed. Advocates (using life cycle analysis) argue that it takes 4-5 months of energy production from the nuclear plant to fully pay back the initial energy investment.^[20] Opponents claim that it depends on the grades of the ores the fuel came from, so a fully pay back can vary from 10 to 18 years.^[21]

Advocates also claim that it is possible to relatively rapidly increase the number of plants. Typical new reactor designs have a construction time of three to four years.^[22] In 1983, 43 plants were being built, before an unexpected fall in fossil fuel prices stopped most new construction. Developing countries like India and China are rapidly increasing their nuclear energy use.^[23][24] However, a Council on Foreign Relations report on nuclear energy argues that a rapid expansion of nuclear power may create shortages in building materials such as reactor-quality concrete and steel, skilled workers and engineers, and safety controls by skilled inspectors. This would drive up current prices.^[25]

Fusion power could solve many of the problems of fission power (the technology mentioned above) but, despite research having started in the 1950s, no commercial fusion reactor is expected before 2050^[26] . Many technical problems remain unsolved. Proposed fusion reactors commonly use deuterium, an isotope of hydrogen, as fuel and in most current designs also lithium. Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years.^[27]

[edit] Hydroelectricity

Main article: Hydroelectricity

Hydroelectricity is the only renewable energy used today that makes a large contribution to world energy production. The long-term technical potential is believed to be 9 to 12 times current hydropower production, but environmental concerns increasingly block new dam construction.^[28] There is a growing interest in mini-hydro projects^[29], which avoid many of the problems of the larger dams.

[edit] Solar power

The CIS Tower, Manchester, England, was clad in Photovoltaic panels at a cost of £5.5 million. It started feeding electricity to the national grid in November 2005.

Main article: Solar power

Commercial solar cells can presently convert about 15 percent of the energy of incident sunlight to electrical energy. If built out as solar collectors, 1 percent of the land today used for crops and pasture could supply the world's total energy consumption. A similar area is used today for hydropower, as the electricity yield per unit area of a solar collector is 50 to 100 times that of an average hydro scheme.^[30] Solar cells can also be placed on top of existing urban infrastructure (see Building integrated photovoltaics) and does then not require re-purposing of cropland or parkland. The German government currently has a huge photovoltaic energy initiative, which is being watched with interest by other countries. Researchers have estimated that algae farms could convert 10 percent of the energy of incident light into biodiesel energy. Solar thermal collectors can capture 70 to 80 percent of insolation as usable heat. Passive solar and Solar chimneys can heat and cool residences and other buildings. A solar updraft tower is another concept. When solar gets cheap enough to compete with other energy resources, it holds huge potential to convey electricity to regions with under-developed grid systems like Africa and India

[edit] Wind power

Main article: Wind power

Wind power is one of the most cost-competitive renewables today. Its long-term technical potential is believed to be five times current global energy consumption, or 40 times current electricity demand. This would require about 13 percent of all land area, or that land area with Class 3 or greater potential at a height of 80 meters. It assumes a placement of six large wind turbines per square kilometer on land. Offshore resources experience mean wind speeds about 90 percent greater than that of land, so offshore resources could contribute substantially more energy.^[31][32] This number could also increase with higher altitude ground based or airborne turbines.^[33]

[edit] Geothermal power

Main article: Geothermal power

Geothermal power and tidal power are the only renewables not dependent on the sun but are today limited to special locations. All available tidal energy is equivalent to one-fourth of total human energy consumption today. Geothermal power has a very large potential if considering all the heat existing inside Earth, although the heat flow from the interior to the surface is only 1/20,000 as great as the energy received from the Sun or about 2-3 times that from tidal power.^[34] At the moment Iceland and New Zealand are two of the greatest users of geothermal energy, although many others also have potential. Countries are also researching hot-dry-rock geothermal technologies which have some possibilities.

[edit] Ocean thermal energy conversion

Ocean thermal energy conversion is another renewable with large potential. Several other variations of utilizing energy from the sun also exist, see renewable energy. Circulating cool water from deep in the ocean up to the surface, and warm water from the surface to the depths produces temperature differentials that useful power can be extracted from.

[edit] Bioenergy

Main article: Biofuels

Biomass (burning biological materials to generate heat), biofuels (processing biological materials to generate fuels such as biodiesel and ethanol), and biogas (using anaerobic digestion to generate methane from biodegradable material & biodegradable waste) are other renewables. Systems such as advanced anaerobic digesters offer the ability to produce medium sized power generation (2MW-10MW) facilities and offer flexibility. They can recover value from biodegradable waste whilst producing power from a renewable energy source.^[35]

[edit] Wave power

Main article: Wave power

Wave power is the extraction of energy from waves in large bodies of water such as oceans and large lakes. Wave power is a form of renewable energy that is on the rise. It should not be confused with Tidal power, which involves construction of a dam or "power tower" (which is basically a large tube which waves push air through to create power with turbines), which are both structures connected to the land. Wave power is harnessed by other means, including floating objects or machines on the floor of the body of water (see Wave farm).

[edit] Pros

• Potentially highly abundant for countries with large coastlines.
• Potentially minimal effect on the environment.
• Wave power is a renewable resource.
• Highly predictable compared to wind and solar.

[edit] Cons

• Requires further research, development and investment in infrastructure.
• Repairs at sea are costlier and more time consuming should generators be damaged (storms, etc).

[edit] Tidal power

Main article: Tidal power

Tidal energy involves building a dam across the opening to a tidal basin, called an estuary. The dam, called a barrage, is composed of turbines, located within tunnels in the dam that rotate when a tide comes in, generating electricity.

[edit] Pros

• Tidal power is free once the dam is built. This is because tidal power harnesses the natural power of tides and does not consume fuel. In addition, the maintenance costs associated with running a tidal station are relatively low.^{[citation needed]}
• Tides are very reliable because it is easy to predict when high and low tides will occur. The tide goes in and out twice a day usually at the predicted times. This makes tidal energy easy to maintain, and positive and negative spikes in energy can be managed.

[edit] Cons

• Tidal energy is not strictly "renewable": because, from basic physics, all energy produced from tidal generation results in an equal loss of the earth's rotational energy. Tidal power relies on the gravitational pull of the Moon and the earth's rotation, which pull the sea backwards and forwards, generating tides.
• It provides power only for around 10 hours each day, when the tide is moving in or out of the basin.
• The amount of power potentially generated is a function of tidal range, In general a tidal range of > 3 metres is necessary.
• The availability of suitable estuaries is limited. Construction of artificial estuaries is highly expensive.
• The barrage construction can affect the transportation system in water. Boats may not be able to cross the barrage outside of a lock system.
• The erection of a barrage may affect the aquatic ecosystems surrounding it. The environment affected by the dam is very wide, altering areas numerous miles upstream and downstream. For example, many birds rely on low tides to unearth mud flats, which are used as feeding areas.
• Maximum power production is limited to 2.5 terawatts. This is the total amount of tidal dissipation or the friction measured by the slowing of the lunar orbit.

[edit] Considerations about renewable energy

Some renewable sources are diffuse and require land and construction material for energy production. The large and sometimes remote areas may also increase energy loss and cost from distribution. On the other hand, some forms allow small-scale production and may be placed very close to or directly at consumer households, businesses, and industries which reduces or eliminates distribution problems.

The large areas affected also means that some renewable energy sources may have some negative environmental impact, although populated suburbs have already been impacted by human development. Hydroelectric dams, like the Aswan Dam, have adverse consequences both upstream and downstream. Some flooded areas also contain decaying organic material that release gases contributing to global warming if not captured. The mining and refining of large amounts of construction material will also affect the environment in the short term.

Aside from hydropower and geothermal power, which are site-specific, renewable supplies often have higher costs than fossil fuels if the impacts of pollution, climate change, and resource depletion are ignored, as is common. Renewables like wind and solar are cost effective in remote areas that are off grid because the cost of a grid connection is high, as is the cost of transporting diesel fuel. Many forms of renewables are cost effective in remote, underdeveloped, and/or low population density areas that are off the grid or on unreliable grids. Transmission of electricity through large grids remote from conventional energy sources is also expensive, and embedding small renewable projects in such locations can cut energy losses significantly. The inefficiency, noise, and refueling requirements of small diesel generators are also factors in favor of renewables in this situation.

Renewable sources are economically viable in less developed areas of the world, where the population density cannot support the financial investment of an electrical grid or petroleum supply network. In such situations, fossil fuel energy sources do not realize economies of scale, and distributed, small-scale electrical generation from renewables is usually more economical and operationally reliable.

Solar thermal is already cost effective for water heating. Grid connected solar cells can be cost effective in a spot-priced market because they generate electricity during peak usage periods when electricity is most costly and because they produce electricity at the point of use thereby avoiding transmission costs.

It is widely expected that renewable energy sources will continue to drop in costs as additional investments are made in R&D and as increased mass production improves the economies of scale. Nuclear power has been subsidized by 0.5-1 trillion dollars since the 1950s. No comparable investment has yet been made in renewable energy. Even so, the technology is improving rapidly. For example, solar cells are a hundred times less expensive today than the 1970s and development continues.^[36][37] Solar breeder technologies, where the energy used to make solar cells is itself solar energy, is also being investigated.^[38]

[edit] Increased efficiency in current energy use

New technology may make better use of already available energy through improved efficiency, such as more efficient fluorescent lamps, engines, and insulation. Using heat exchangers, it is possible to recover some of the energy in waste warm water and air, for example to preheat incoming fresh water. Hydrocarbon fuel production from pyrolysis could also be in this category, allowing recovery of some of the energy in hydrocarbon waste. Meat production is energy inefficient compared to the production of protein sources like soybean or Quorn. Already existing power plants often can and usually are made more efficient with minor modifications due to new technology. New power plants may become more efficient with technology like cogeneration. New designs for buildings may incorporate techniques like passive solar. Light-emitting diodes are gradually replacing the remaining uses of light bulbs. Note that none of these methods allows perpetual motion, as some energy is always lost to heat.

Mass transportation increases energy efficiency compared to widespread conventional automobile use while air travel is regarded as inefficient. Conventional combustion engine automobiles have continually improved their efficiency and may continue to do so in the future, for example by reducing weight with new materials. Hybrid vehicles can save energy by allowing the engine to run more efficiently, regaining energy from braking, turning off the motor when idling in traffic, etc. More efficient ceramic or diesel engines can improve mileage. Electric vehicles such as Maglev, trolleybuses, and PHEVs are more efficient during use (but maybe not if doing a life cycle analysis) than similar current combustion based vehicles, reducing their energy consumption during use by 1/2 to 1/4. Microcars or motorcycles may replace automobiles carrying only one or two people. Transportation efficiency may also be improved by in other ways, see automated highway system.

Electricity distribution may change in the future. New small scale energy sources may be placed closer to the consumers so that less energy is lost during electricity distribution. New technology like superconductivity or improved power factor correction may also decrease the energy lost. Distributed generation permits electricity "consumers", who are generating electricity for their own needs, to send their surplus electrical power back into the power grid.

Various market-based mechanisms have been proposed as means of increasing efficiency, such as deregulation of electricity markets, Negawatt power, and trading of emission rights. Smart appliances that require only intermittent use (like laundry machines and dishwashers) could be programmed to start only when demand is low at night or during sunny or windy periods of peak production in the case of solar and wind power.

[edit] Energy storage and transportation fuel

Main article: energy storage

Energy is often needed at times and locations it is not available, especially for powering transportation vehicles. Such needs require transportation fuels and methods of storing energy. In some situations energy demand can be shifted.

[edit] Electric-powered vehicles

Main articles: battery, battery electric vehicle

Batteries are used to store energy in a chemical form. As an alternative energy, batteries can be used to store energy in battery electric vehicles. Battery electric vehicles can be charged from the grid when the vehicle is not in use. Because the energy is derived from electricity, battery electric vehicles make it possible to use other forms of alternative energy such as wind, solar, geothermal, nuclear, or hydroelectric.

[edit] Pros

• Produces zero direct emissions to help counteract the effects of global warming.
• Batteries are a mature technology, no new expensive research and development is needed to implement technology.
• Current lead acid battery technology offers 50+ miles range on one charge. ^[39]
• The Tesla Roadster has a 200 mile range on one charge.
• Batteries make it possible for stationary alternative energy generation such as solar, wind, hydroelectric, nuclear, or hydroelectric.
• Electric motors are 90% efficient compared to about 20% efficiency of an internal combustion engine. ^[40]
• No new major infrastructure is needed to charge battery electric vehicles.
• Battery electric vehicles have fewer moving parts than internal combustion engines, thus improving the reliability of the vehicle.
• Battery electric vehicles are quiet compared to internal combustion engines.
• Multiple electric vehicles sold out including the General Motors EV1 and the Tesla Roadster proving the demand for battery electric vehicles.
• Operation of a battery electric vehicle is approximately 2 to 4 cents per mile. About a sixth the price of operating a gasoline vehicle. ^[41]
• The use of Battery Electric Vehicles eliminates the dependency on foreign oil.

[edit] Cons

• The energy used in electric vehicles needs to be derived from other sources.
• Current battery technology is expensive.
• Battery electric vehicles have a relative short range compared to internal combustion engine vehicles.
• Most battery refueling methods are time consuming compared to gasoline and diesel refueling

[edit] Transportation alternatives

Nuclear power has been used in large ships.^[42] High technology sails could provide some of the power for ships.^[43] Airships require less onboard fuel than a traditional aircraft and combining airship technology with glider technology may eliminate onboard fuel completely.^[44] Personal rapid transit and some mass transportation systems, like trolleybus, metro or magnetic levitation trains, can use electricity directly from the grid and do not need a liquid fuel or battery.

[edit] Speculative

This section does not cite any references or sources. Please improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (tagged since June 2006)

In the long-term future space exploration could yield a number of energy sources, though they are unlikely to be relevant in tackling humanity's current difficulties with energy sources.

The nearest-term possibility is solar power satellites, where solar cells are placed on orbiting platforms in 24-hour sunlight; the energy is then beamed to earth as microwaves received by arrays of receiving antennas. Most such proposals rely on a radical lowering of launch costs to make them economically viable. In order to overcome the launch costs of solar power satellites, O'Neill et al proposed using lunar material for a low profile, rapid (90 day doubling time) expansion system for creating such a massive industrial development using partially self-replicating systems under telepresence control of remote human workers^[45]

Fusion on earth could be possible in the future. If so, that could solve humanity's energy needs to almost ad-infinitum. Fissionable materials could theoretically be obtained from asteroid mining; however, the technical barriers to asteroid mining are probably considerably higher than those of breeder reactors, which remove any practical supply constraints on fission power. Another interesting long-term possibility is the mining of helium-3 from the Moon for use in aneutronic fusion reactors, which have several advantages over the fusion reactor designs currently being experimented with. Helium-3 is unavailable in quantity on Earth. However, even "conventional" fusion power reactors are decades away from commercialization. Another suggestion is electrodynamic tethers.

In the very distant future, a spacefaring humanity has a number of options for very large-scale power generation; as well as fusion and very large-scale solar power (of which the ultimate such is the Dyson sphere) there has been speculation as to how an extremely advanced society might exploit the mass-energy conversion capabilities of black holes (like the accretion disc). Such technologies are obviously far, far, beyond our present capabilities, and are at this stage essentially thought experiments for engineers and science fiction writers.

[edit] See also

Energy Portal

• Energy harvesting and storing
  • Comparison of power plants
  • Distributed generation
  • Fusion power
  • Inertial fusion energy
  • Renewable energy
  • Wind power
  • Solar power
  • Thermal depolymerization
• Energy usage
  • 2000 Watt society
  • Action on climate change
  • Energy conservation
  • Earth's energy budget
  • Energy crisis
  • Energy: world resources and consumption
  • Kardashev scale
  • Oil phase-out in Sweden
  • World energy resources and consumption
  • Economies
    • Comparison of automobile fuel technologies
    • Hydrogen economy
    • The Hype about Hydrogen
    • Liquid nitrogen economy
    • Lithium economy
    • Low-carbon economy
    • Vegetable oil economy
    • Zinc economy
• Issues
  • Mitigation of global warming
  • Environmental concerns with electricity generation
  • Peak Oil

[edit] External links

This article or section may contain spam. Wikipedia spam consists of external links mainly intended to promote a website. Wikipedia spam also consists of external links to websites which primarily exist to sell goods or services, use objectionable amounts of advertising, or require payment to view the relevant content. If you are familiar with the content of the external links, please help by removing promotional links in accordance with Wikipedia:External links. (You can help!)

[edit] Organizations

• IEA Energy Information Centre
  • World Energy Outlook series, free before 2003, different focus each year
  • Free publications from IEA
• WEC Survey of Energy Resources
  • Online publications from WEC
  • Links to a broad range of international governmental and non-governmental organisations
• U.S. Energy Information Agency
  • International energy outlook 2004
  • Related Energy Links
• U.S. The Alternative Fuels Data Center
• U.S. Office of Fossil Energy
• Rocky Mountain Institute articles on energy
• Electricity Storage Association on articles on energy storage
• Information Network on the Technology of Utilisation and Sustainability of Energy Resources
• ASPO Association for the Study of Peak Oil & Gas
• Energy and Climate publications from the Tellus Institute
• OPEC, Organisation of Oil Exporting Countries
  • Open Oil Outlook to 2025

[edit] Articles

• Order of Magnitude Morality
• Do we need nuclear power?
• Progress and its sustainability
• Nine Critical Questions to Ask About Alternative Energy
• World energy beyond 2050
• Critical Hour: Three Mile Island, The Nuclear Legacy, And National Security Online book by Albert J. Fritsch, Arthur H. Purcell, and Mary Byrd Davis (2005)
• Alternate Energy: The Investing Perspective
• The History and Future of World Energy, The Quaker Economist, vol. 7, #155, 2007.

[edit] References

• Greene, D.L. & J.L. Hopson. (2003). Running Out of and Into Oil: Analyzing Global Depletion and Transition Through 2050 ORNL/TM-2003/259, Oak Ridge National Laboratory, Oak Ridge, Tennessee, Octobe
• Kahn, H. et al. (1976) The Next 200 Years: A Scenario for America and the World ISBN 0-349-12071-4
• Rodenbeck, Christopher T. and Chang, Kai, "A Limitation on the Small-Scale Demonstration of Retrodirective Microwave Power Transmission from the Solar Power Satellite", IEEE Antennas and Propagation Magazine, August 2005, pp. 67–72.
• The above sites Solar Power Satellites Office of Technology Assessment, US Congress, OTA-E-144, Aug. 1981.

[edit] Inline references

• http://www.madsci.org/posts/archives/mar2002/1017275290.Es.r.html