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Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Commercial CSP plants were first developed in the 1980s, and the 354 MW SEGS CSP installation is the largest solar power plant in the world and is located in the Mojave Desert of California. The 80 MW Sarnia Photovoltaic Power Plant in Canada, is the world’s largest photovoltaic plant. Experimental approaches to solar power include concentrated photovoltaics systems, thermovoltaic devices, and space-based solar power.

Solar power is an intermittent energy source, meaning that solar power is not available at all times, and is normally supplemented by storage or another energy source, for example with wind power and hydropower.

Applications

Solar power is the conversion of sunlight into electricity. Sunlight can be converted directly into electricity using photovoltaics (PV), or indirectly with concentrated solar power (CSP), which normally focuses the sun's energy to boil water which is then used to provide power, and other technologies, such as the sterling engine dishes which use a sterling cycle engine to power a generator. Photovoltaics were initially used to power small and medium-sized applications, from the calculator powered by a single solar cell to off-grid homes powered by a photovoltaic array.

The only significant problem with solar power is installation cost, although cost has been decreasing due to the learning curve. Developing countries in particular may not have the funds to build solar power plants, although small solar applications are now replacing other sources in the developing world.

Concentrating solar power

Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated heat is then used as a heat source for a conventional power plant. A wide range of concentrating technologies exists; the most developed are the parabolic trough, the concentrating linear fresnel reflector, the Stirling dish and the solar power tower. Various techniques are used to track the Sun and focus light. In all of these systems a working fluid is heated by the concentrated sunlight, and is then used for power generation or energy storage.

A parabolic trough consists of a linear parabolic reflector that concentrates light onto a receiver positioned along the reflector's focal line. The receiver is a tube positioned right above the middle of the parabolic mirror and is filled with a working fluid. The reflector is made to follow the Sun during the daylight hours by tracking along a single axis. Parabolic trough systems provide the best land-use factor of any solar technology. The SEGS plants in California and Acciona's Nevada Solar One near Boulder City, Nevada are representatives of this technology. The Suntrof-Mulk parabolic trough, developed by Melvin Prueitt, uses a technique inspired by Archimedes' principle to rotate the mirrors.

Concentrating linear fresnel reflectors are CSP-plants which use many thin mirror strips instead of parabolic mirrors to concentrate sunlight onto two tubes with working fluid. This has the advantage that flat mirrors can be used which are much cheaper than parabolic mirrors, and that more reflectors can be placed in the same amount of space, allowing more of the available sunlight to be used. Concentrating linear fresnel reflectors can be used in either large or more compact plants.

A stirling solar dish, or dish engine system, consists of a stand-alone parabolic reflector that concentrates light onto a receiver positioned at the reflector's focal point. The reflector tracks the Sun along two axes. Parabolic dish systems give the highest efficiency among CSP technologies. The 50 kW Big Dish in Canberra, Australia is an example of this technology. The stirling solar dish combines a parabolic concentrating dish with a stirling heat engine which normally drives an electric generator. The advantages of stirling solar over photovoltaic cells are higher efficiency of converting sunlight into electricity and longer lifetime.

A solar power tower uses an array of tracking reflectors (heliostats) to concentrate light on a central receiver atop a tower. Power towers are more cost effective, offer higher efficiency and better energy storage capability among CSP technologies. The Solar Two in Barstow, California and the Planta Solar 10 in Sanlucar la Mayor, Spain are representatives of this technology.

Photovoltaics

A solar cell, or photovoltaic cell (PV), is a device that converts light into electric current using the photoelectric effect. The first solar cell was constructed by Charles Fritts in the 1880s. Although the prototype selenium cells converted less than 1% of incident light into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery. Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the silicon solar cell in 1954. These early solar cells cost 286 USD/watt and reached efficiencies of 4.5–6%.

Solar power has great potential, but in 2008 supplied less than 0.02% of the world's total energy supply. There are many competing technologies, including fourteen types of photovoltaic cells, such as thin film, monocrystalline silicon, polycrystalline silicon, and amorphous cells, as well as multiple types of concentrating solar power. It is too early to know which technology will become dominant.

The earliest significant application of solar cells was as a back-up power source to the Vanguard I satellite in 1958, which allowed it to continue transmitting for over a year after its chemical battery was exhausted. The successful operation of solar cells on this mission was duplicated in many other Soviet and American satellites, and by the late 1960s, PV had become the established source of power for them. Photovoltaics went on to play an essential part in the success of early commercial satellites such as Telstar, and they remain vital to the telecommunications infrastructure today.

The high cost of solar cells limited terrestrial uses throughout the 1960s. This changed in the early 1970s when prices reached levels that made PV generation competitive in remote areas without grid access. Early terrestrial uses included powering telecommunication stations, off-shore oil rigs, navigational buoys and railroad crossings. These off-grid applications accounted for over half of worldwide installed capacity until 2004.

The 1973 oil crisis stimulated a rapid rise in the production of PV during the 1970s and early 1980s. Economies of scale which resulted from increasing production along with improvements in system performance brought the price of PV down from 100 USD/watt in 1971 to 7 USD/watt in 1985. Steadily falling oil prices during the early 1980s led to a reduction in funding for photovoltaic R&D and a discontinuation of the tax credits associated with the Energy Tax Act of 1978. These factors moderated growth to approximately 15% per year from 1984 through 1996.

Since the mid-1990s, leadership in the PV sector has shifted from the US to Japan and Europe. Between 1992 and 1994 Japan increased R&D funding, established net metering guidelines, and introduced a subsidy program to encourage the installation of residential PV systems. As a result, PV installations in the country climbed from 31.2 MW in 1994 to 318 MW in 1999, and worldwide production growth increased to 30% in the late 1990s.

Germany became the leading PV market worldwide since revising its Feed-in tariff system as part of the Renewable Energy Sources Act. Installed PV capacity has risen from 100 MW in 2000 to approximately 4,150 MW at the end of 2007. After 2007, Spain became the largest PV market after adopting a similar feed-in tariff structure in 2004, installing almost half of the photovoltaics (45%) in the world, in 2008, while France, Italy, South Korea and the U.S. have seen rapid growth recently due to various incentive programs and local market conditions. Recent Studies have shown that the global PV market is forecast to exceed 16 GW in the year 2010. The power output of domestic photovoltaic devices is usually described in kilowatt-peak (kWp) units, as most are from 1 to 10 kW.

Development, deployment and economics

The early development of solar technologies starting in the 1860s was driven by an expectation that coal would soon become scarce. However development of solar technologies stagnated in the early 20th century in the face of the increasing availability, economy, and utility of coal and petroleum. The 1973 oil embargo and 1979 energy crisis caused a reorganization of energy policies around the world and brought renewed attention to developing solar technologies. Deployment strategies focused on incentive programs such as the Federal Photovoltaic Utilization Program in the US and the Sunshine Program in Japan. Other efforts included the formation of research facilities in the US (SERI, now NREL), Japan (NEDO), and Germany (Fraunhofer Institute for Solar Energy Systems ISE).

Between 1970 and 1983 photovoltaic installations grew rapidly, but falling oil prices in the early 1980s moderated the growth of PV from 1984 to 1996. Since 1997, PV development has accelerated due to supply issues with oil and natural gas, global warming concerns, and the improving economic position of PV relative to other energy technologies. Photovoltaic production growth has averaged 40% per year since 2000 and installed capacity reached 10.6 GW at the end of 2007, and 14.73 GW in 2008. Since 2006 it has been economical for investors to install photovoltaics for free in return for a long term power purchase agreement. 50% of commercial systems were installed in this manner in 2007 and it is expected that 90% will by 2009. Nellis Air Force Base is receiving photoelectric power for about 2.2 ¢/kWh and grid power for 9 ¢/kWh.

Commercial concentrating solar thermal power (CSP) plants were first developed in the 1980s. CSP plants such as SEGS project in the United States have a levelized energy cost (LEC) of 12–14 ¢/kWh. The 11 MW PS10 power tower in Spain, completed in late 2005, is Europe's first commercial CSP system, and a total capacity of 300 MW is expected to be installed in the same area by 2013.

Operational Solar Thermal Power Stations

Capacity (MW)	Name	Country	Location	Notes
354	Solar Energy Generating Systems	USA	Mojave Desert California	Collection of 9 units
150	Solnova	Spain	Seville	Completed 2010
100	Andasol solar power station	Spain	Granada	Completed 2009
64	Nevada Solar One	USA	Boulder City, Nevada
50	Ibersol Ciudad Real	Spain	Puertollano, Ciudad Real	Completed May 2009
50	Alvarado I	Spain	Badajoz	Completed July 2009
50	Extresol 1	Spain	Torre de Miguel Sesmero (Badajoz)	Completed February 2010
50	La Florida	Spain	Alvarado (Badajoz)	completed July 2010

Solar installations in recent years have also largely begun to expand into residential areas, with governments offering incentive programs to make "green" energy a more economically viable option. In Canada the RESOP (Renewable Energy Standard Offer Program), introduced in 2006, and updated in 2009 with the passage of the Green Energy Act, allows residential homeowners in Ontario with solar panel installations to sell the energy they produce back to the grid (i.e., the government) at 42¢/kWh, while drawing power from the grid at an average rate of 6¢/kWh. The program is designed to help promote the government's green agenda and lower the strain often placed on the energy grid at peak hours. In March, 2009 the proposed FIT was increased to 80¢/kWh for small, roof-top systems (≤10 kW).

Photovoltaics are 85 times as efficient as growing corn for ethanol. On a 300 feet (91 m) by 300 feet (1 hectare) plot of land enough ethanol can be produced to drive a car 30,000 miles (48,000 km) per year or 2,500,000 miles (4,000,000 km) by covering the same land with photo cells. The deserts of the South Western United States could produce sufficient electricity to fulfill all of the electrical needs of the United States, and could use electrolysis to produce Hydrogen from water to power aircraft.

The annual International Conference on Solar Photovoltaic Investments, organized by EPIA notes that photovoltaics provides a secure, reliable return on investment, with modules typically lasting 25 to 40 years and with a payback on investment of between 8 to 12 years.

Energy storage methods

Solar energy is not available at night, making energy storage an important issue in order to provide the continuous availability of energy. Both wind power and solar power are intermittent energy sources, meaning that all available output must be taken when it is available and either stored for when it can be used, or transported, over transmission lines, to where it can be used. Wind power and solar power tend to be somewhat complementary, as there tends to be more wind in the winter and more sun in the summer, but on days with no sun and no wind the difference needs to be made up in some manner. The Institute for Solar Energy Supply Technology of the University of Kassel pilot-tested a combined power plant linking solar, wind, biogas and hydrostorage to provide load-following power around the clock, entirely from renewable sources.

Solar energy can be stored at high temperatures using molten salts. Salts are an effective storage medium because they are low-cost, have a high specific heat capacity and can deliver heat at temperatures compatible with conventional power systems. The Solar Two used this method of energy storage, allowing it to store 1.44 TJ in its 68 m³ storage tank, enough to provide full output for close to 39 hours, with an efficiency of about 99%.

Off-grid PV systems have traditionally used rechargeable batteries to store excess electricity. With grid-tied systems, excess electricity can be sent to the transmission grid. Net metering programs give these systems a credit for the electricity they deliver to the grid. This credit offsets electricity provided from the grid when the system cannot meet demand, effectively using the grid as a storage mechanism. Credits are normally rolled over month to month and any remaining surplus settled annually.

Pumped-storage hydroelectricity stores energy in the form of water pumped when surplus electricity is available, from a lower elevation reservoir to a higher elevation one. The energy is recovered when demand is high by releasing the water: the pump becomes a turbine, and the motor a hydroelectric power generator.

Experimental solar power

Concentrated photovoltaics (CPV) systems employ sunlight concentrated onto photovoltaic surfaces for the purpose of electrical power production. Solar concentrators of all varieties may be used, and these are often mounted on a solar tracker in order to keep the focal point upon the cell as the Sun moves across the sky. Luminescent solar concentrators (when combined with a PV-solar cell) can also be regarded as a CPV system. Luminescent solar concentrators are useful as they can improve performance of PV-solar panels drastically.

Thermoelectric, or "thermovoltaic" devices convert a temperature difference between dissimilar materials into an electric current. First proposed as a method to store solar energy by solar pioneer Mouchout in the 1800s, thermoelectrics reemerged in the Soviet Union during the 1930s. Under the direction of Soviet scientist Abram Ioffe a concentrating system was used to thermoelectrically generate power for a 1 hp engine. Thermogenerators were later used in the US space program as an energy conversion technology for powering deep space missions such as Cassini, Galileo and Viking. Research in this area is focused on raising the efficiency of these devices from 7–8% to 15–20%.

Space-based solar power is a theoretical design for the collection of solar power in space, for use on Earth. SBSP differs from the usual method of solar power collection in that the solar panels used to collect the energy would reside on a satellite in orbit, often referred to as a solar power satellite (SPS), rather than on Earth's surface. In space, collection of the Sun's energy is unaffected by the day/night cycle, weather, seasons, or the filtering effect of Earth's atmospheric gases. Average solar energy per unit area outside Earth's atmosphere is on the order of ten times that available on Earth's surface. However, there is no shortage of energy reaching the surface. The amount of solar energy reaching the surface of the planet each year is about twice the amount of energy that will be obtained forever from coal, oil, natural gas, and mined Uranium, combined, even using breeder reactors.

See also

• Green electricity
• High voltage direct current
• Levelised energy cost
• List of conservation topics
• List of photovoltaic power stations
• List of renewable energy organizations
• List of solar energy topics
• List of solar thermal power stations
• Renewable heat
• Solar easement
• Solar energy
• Solar lamp
• Thin-film cell
• Timeline of solar energy
• World energy resources and consumption

Notes

1. Cost Of Installed Solar Photovoltaic Systems Drops Significantly Over The Last Decade retrieved 19 May 2009
2. Govt to bear 80% cost of generating solar power retrieved 19 May 2009
3. In India’s Sea of Darkness: An Unsustainable Island of Decentralized Energy Production retrieved 19 May 2009
4. Martin and Goswami (2005), p. 45
5. Concentrated Solar Thermal Power - Now Retrieved 19 August 2008
6. ^ "Concentrating Solar Power in 2001 - An IEA/SolarPACES Summary of Present Status and Future Prospects" (PDF). International Energy Agency - SolarPACES. Retrieved 2008-07-02.
7. "UNLV Solar Site". University of Las Vegas. Retrieved 2008-07-02.
8. Suntrof-Mulk Parabolic Trough
9. Compact CLFR
10. Ausra compact CLFR introducing cost-saving solar rotation features
11. "An Assessment of Solar Energy Conversion Technologies and Research Opportunities" (PDF). Stanford University - Global Climate Change & Energy Project. Retrieved 2008-07-02.
12. David Shukman (2 May 2007). "Power station harnesses Sun's rays". BBC News. Retrieved 2008-07-02.
13. Perlin (1999), p. 147
14. Perlin (1999), p. 18–20
15. Perlin (1999), p. 29
16. Perlin (1999), p. 29–30, 38
17. Technologies
18. Perlin (1999), p. 45–46
19. Perlin (1999), p. 49–50
20. Perlin (1999), p. 49–50, 190
21. Perlin (1999), p. 57–85
22. ^ "Renewables 2007 Global Status Report" (PDF). Worldwatch Institute. p. 11. Retrieved 2008-04-30.
23. "Photovoltaic Milestones". Energy Information Agency - Department of Energy. Retrieved 2008-05-20.
24. Perlin (1999), p. 50, 118
25. "World Photovoltaic Annual Production, 1971-2003". Earth Policy Institute. Retrieved 2008-05-29.
26. "Policies to Promote Non-hydro Renewable Energy in the United States and Selected Countries" (PDF). Energy Information Agency – Department of Energy. Retrieved 2008-05-29.
27. Foster, Robert. "Japan Pholtovoltaics Market Overview" (PDF). Department of Energy. Retrieved 2008-06-05.
28. Handleman, Clayton. "An Experience Curve Based Model for the Projection of PV Module Costs and Its Policy Implications" (PDF). Heliotronic. Retrieved 2008-05-29.
29. "Renewable energy sources in figures - national and international development" (PDF). Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (Germany). Retrieved 2008-05-29.
30. "Marketbuzz 2008: Annual World Solar Pholtovoltaic Industry Report". solarbuzz. Retrieved 2008-06-05.
31. "Trends in Photovoltaic Applications - Survey report of selected IEA countries between 1992 and 2006" (PDF). International Energy Agency. Retrieved 2008-06-05.
32. http://solarpowerengineering.com/
33. "Live Sites - links to over 800 monitored solar panels". Fat Spaniel. Retrieved 2009-05-18. The live feeds shown here cite figures in kilowatt-peak (kWp) units.
34. Butti and Perlin (1981), p. 63, 77, 101
35. Butti and Perlin (1981), p. 249
36. Yergin (1991), p. 634, 653-673
37. "Chronicle of Fraunhofer-Gesellschaft". Fraunhofer-Gesellschaft. Retrieved 2007-11-04.
38. Solar: photovoltaic: Lighting Up The World retrieved 19 May 2009
39. "Global Market Outlook Until 2013" (PDF). European Photovoltaic Industry Association. Retrieved 2009-05-22.
40. Solar Power Services: How PPAs are Changing the PV Value Chain February 11, 2008, retrieved 21 May 2009
41. Nellis Solar Power System
42. "An Argument for Feed-in Tariffs" (PDF). European Photovoltaic Industry Association. Retrieved 2008-06-09.
43. "DOE Concentrating Solar Power 2007 Funding Opportunity Project Prospectus" (PDF). Department of Energy. Retrieved 2008-06-12.
44. "PS10". SolarPACES (Solar Power and Chemical Energy Systems). Retrieved 2008-06-24.
45. Abengoa Rakes in $426M for 4 Solar Power Plants
46. "Abengoa Begins Operation of 50MW Concentrating Solar Power Plant". SustainableBusiness.com News. May 6, 2010. Retrieved 2010-05-07.
47. Abengoa Solar begins commercial operation of Solnova 1
48. Abengoa Solar begins commercial operation of Solnova 3
49. Abengoa Solar Reaches Total of 193 Megawatts Operating
50. Acciona y ACS inscriben sus termosolares en el registro de Industria
51. ACS aumenta un 22,6% las ganancias de su negocio de 'energía verde' en la primera mitad de año
52. José María Barreda and Ignacio Galán open IBERDROLA RENOVABLES’ first solar termal power plant
53. Acciona Status Solarpaces 2008 p.25
54. ACCIONA Energía develops 900-million-euro renewables projects in the region of Extremadura
55. ACCIONA opens its first CSP plant in Spain, in Extremadura
56. ^ Lokalizacion de Centrales Termosolares de Espana
57. Solar Thermal Power Generation - A Spanish Success Story
58. ACS LAUNCHES THE OPERATION PHASE OF ITS THIRD DISPATCHABLE 50 MW THERMAL POWER PLANT IN SPAIN, EXTRESOL-1
59. Spain - A Solar Thermal Powerhouse
60. RESOP Program Update
61. Solar program in Ontario
62. Proposed Feed-In Tariff Prices for Renewable Energy Projects in Ontario
63. David Comarow, "Here Comes the Sun," Kyoto Planet Sustainable Enterprise Report, November 2008, Whitepaper.
64. PV Resources (2010). World's largest photovoltaic power plants
65. Germany Turns On World's Biggest Solar Power Project
66. Lieberose solar farm becomes Germany's biggest, World's second-biggest
67. Amareleja Solar Central solar which cost 261 ME started today (29 Dec 08) at full capacity retrieved 21 May 2009
68. Large photovoltaic plant in Muldentalkreis
69. Germany's largest Solar parks connected to the grid (19 Dec 08)
70. FVE CZECH
71. FVE CZECH NOVUM s.r.o.
72. 3rd International Conference on Solar Photovoltaic Investments
73. Carr (1976), p. 85
74. Wind + sun join forces at Washington power plant Retrieved 31 January 2008
75. "The Combined Power Plant: the first stage in providing 100% power from renewable energy". SolarServer. 2008. Retrieved 2008-10-10. {{cite web}}: Unknown parameter |month= ignored (help)
76. "Advantages of Using Molten Salt". Sandia National Laboratory. Retrieved 2007-09-29.
77. "PV Systems and Net Metering". Department of Energy. Archived from the original on 2008-07-04. Retrieved 2008-07-31.
78. "Pumped Hydro Storage". Electricity Storage Association. Retrieved 2008-07-31.
79. MSU-CSET Participation Archive with notation in the Murray Ledger & Times
80. What is a luminescent solar concentrator?
81. Perlin and Butti (1981), p. 73
82. Halacy (1973), p. 76
83. Tritt (2008), p. 366–368
84. Exergy (available energy) Flow Charts 2.7 YJ solar energy each year for two billion years vs. 1.4 YJ non-renewable resources available once.

References

• Butti, Ken (1981). A Golden Thread (2500 Years of Solar Architecture and Technology). Van Nostrand Reinhold. ISBN 0-442-24005-8. {{cite book}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
• Carr, Donald E. (1976). Energy & the Earth Machine. W. W. Norton & Company. ISBN 0-393-06407-7.
• Halacy, Daniel (1973). The Coming Age of Solar Energy. Harper and Row. ISBN 0-380-00233-7.
• Martin, Christopher L. (2005). Solar Energy Pocket Reference. International Solar Energy Society. ISBN 0-9771282-0-2. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Mills, David (2004). "Advances in solar thermal electricity technology". Solar Energy. 76 (1–3): 19–31. doi:10.1016/S0038-092X(03)00102-6.
• Perlin, John (1999). From Space to Earth (The Story of Solar Electricity). Harvard University Press. ISBN 0-674-01013-2.
• Tritt, T.; Böttner, H.; Chen, L. (2008). "Thermoelectrics: Direct Solar Thermal Energy Conversion". MRS Bulletin. 33 (4): 355–372.
• Yergin, Daniel (1991). The Prize: The Epic Quest for Oil, Money, and Power. Simon & Schuster. p. 885. ISBN 978-0-671-79932-8.

External links

• "How do Photovoltaics Work?". NASA.
• "Best Regions for Solar Power (US)".

v t e Solar energy
Index Outline Timeline
Concepts	The Sun Solar irradiance
Solar power	Thermal Passive solar building design Solar air conditioning Solar chimney Solar pond Solar water heating Thermal mass Photovoltaics and related topics Concentrator photovoltaics Floating solar Nanocrystal solar cell Organic solar cell Photovoltaic array (and systems) Photovoltaic effect Photovoltaic module (solar panel) Photovoltaic power station Solar cell Concentrated Concentrator photovoltaics Heliostat Parabolic trough Solar power tower Solar tracker Experimental and proposed Solar chemical and artificial photosynthesis Solar-pumped laser Solar updraft tower Thermoelectric generator Space-related Magnetic sail Solar sail Solar thermal rocket Space-based solar power By country Albania Armenia Australia Austria Belgium Brazil Canada China Czech Republic Denmark Georgia Germany Greece India Israel Italy Japan Kosovo Lithuania Mexico Morocco Myanmar Netherlands New Zealand Pakistan Portugal Romania Saudi Arabia Somalia South Africa Spain Thailand Turkey Ukraine United Kingdom United States Yemen Legal Solar Shade Control Act
Distribution and uses	Storage Grid energy storage Phase-change material Thermal energy storage seasonal Adoption Cost by source Feed-in tariff Financial incentives for photovoltaics Net metering Applications Electric aircraft Electric boat Solar balloon Solar vehicle Solar water heating
Applications	Agriculture and horticulture Agrivoltaic Greenhouse Polytunnel Row cover Solar-powered pump Building Building-integrated photovoltaics Passive solar building design Urban heat island Lighting Daylighting Hybrid solar lighting Light tube Solar lamp Solar Tuki Process heat Salt evaporation pond Solar furnace Solar pond Cooking Solar cooker Disinfection Soil solarization Solar water disinfection Desalination Desalination Solar still Water heating Solar combisystem Solar controller Solar water heating
See also	Photovoltaics Solar power by country
Category Commons

v t e Electricity delivery
Concepts	Automatic generation control Backfeeding Base load Demand factor Droop speed control Electric power Electric power quality Electrical fault Energy demand management Energy return on investment Grid code Grid energy storage Grid strength Home energy storage Load-following Merit order Nameplate capacity Peak demand Power factor Power-flow study Repowering Utility frequency Variability Vehicle-to-grid
Sources	Non-renewable Fossil fuel power station Coal Natural gas Oil shale Petroleum Nuclear Renewable Biofuel Biogas Biomass Geothermal Hydro Marine Current Osmotic Thermal Tidal Wave Solar Sustainable biofuel Wind
Generation	AC power Cogeneration Combined cycle Cooling tower Induction generator Micro CHP Microgeneration Rankine cycle Three-phase electric power Virtual power plant
Transmission and distribution	Demand response Distributed generation Dynamic demand Electric power distribution Electric power system Electric power transmission Electrical busbar system Electrical grid Electrical substation Electricity retailing High-voltage direct current High-voltage shore connection Interconnector Load management Mains electricity by country Overhead power line Power station Pumped hydro Single-wire earth return Smart grid Super grid Transformer Transmission system operator (TSO) Transmission tower Utility pole
Failure modes	Black start Brownout Cascading failure Power outage Rolling blackout
Protective devices	Arc-fault circuit interrupter Circuit breaker Earth-leakage Sulfur hexafluoride Generator interlock kit Numerical relay Power system protection Protective relay Residual-current device (GFI)
Economics and policies	Availability factor Capacity factor Carbon offsets and credits Cost of electricity by source Energy subsidies Environmental tax Feed-in tariff Fossil fuel phase-out Load factor Net metering Pigouvian tax Renewable Energy Certificates Renewable energy commercialization Renewable Energy Payments Spark/Dark/Quark/Bark spread
Statistics and production	Electric energy consumption List of electricity sectors
Category

fuck these niggers bitch

• Energy conversion
• Alternative energy
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• Sun