View source for Engineering:Capacity factor

{{Short description|Electrical production measure}}
[[File:US EIA monthly capacity factors 2011-2013.png|thumb|upright=1.5|[[Energy Information Administration|US EIA]] monthly capacity factors 2011-2013]]
The net '''capacity factor''' is the unitless ratio of actual electrical energy output over a given period of time to the theoretical maximum electrical energy output over that period.<ref>{{cite web|url= https://www.nrc.gov/reading-rm/basic-ref/glossary/capacity-factor-net.html |website= nrc.gov |title= Capacity factor (net) |access-date= 2017-02-11}}</ref> The theoretical maximum energy output of a given installation is defined as its continuous operation at full [[Physics:Nameplate capacity|nameplate capacity]] over the relevant period. The capacity factor can be calculated for any electricity producing installation, such as a [[Engineering:Fuel|fuel]]-consuming power plant or one using [[Engineering:Renewable energy|renewable energy]], such as wind, the sun or hydro-electric installations. The average capacity factor can also be defined for any class of such installations and can be used to compare different types of electricity production.

The actual energy output during that period and the capacity factor vary greatly depending on a range of factors. The capacity factor can never exceed the [[Engineering:Availability factor|availability factor]], or [[Uptime|uptime]] during the period. Uptime can be reduced due to, for example, reliability issues and maintenance, scheduled or unscheduled. Other factors include the design of the installation, its location, the type of electricity production and with it either the fuel being used or, for renewable energy, the local weather conditions. Additionally, the capacity factor can be subject to regulatory constraints and market forces, potentially affecting both its fuel purchase and its electricity sale.

The capacity factor is often computed over a timescale of a year, [[Method of averaging|averaging out]] most temporal fluctuations. However, it can also be computed for a month to gain insight into seasonal fluctuations. Alternatively, it can be computed over the lifetime of the power source, both while operational and after decommissioning. A capacity factor can also be expressed and converted to [[Physics:Full load hour|full load hour]]s.

== Formula ==
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| Capacity factor || {{calculator|type=plain|default=0.5|formula=round(energy/(capacity*time*hoursConversion),4)|NaN-text=&#32;}}
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<math>\mathrm{CF} = \frac{E_t}{P_n \times t}</math>

where:
* <math>E_t</math> is the total [[Physics:Electrical energy|electrical energy]] over the time period <math>t</math>, e.g., in [[Kilowatt-hour|kilowatt-hour]]s (kWh) or megajoules (MJ),
* <math>P_n</math> is the [[Physics:Nameplate capacity|nameplate capacity]] (rated or installed power) of the device or system, e.g., in kilowatts (kW),
* <math>t</math> is the total time period considered, e.g., in hours or years. 

If consistent units are used for energy and power—such as megawatt-hours (MWh) for energy and megawatts (MW) for power—and time is expressed in hours, the units "cancel out". For example, if a 1&nbsp;MW plant produces 0.5&nbsp;MWh in one hour, its capacity factor is:

<math>\mathrm{CF} = \frac{0.5 \, \mathrm{MWh}}{1 \, \mathrm{MW} \times 1 \, \mathrm{h}} = 0.5 = 50%</math>

==Sample calculations==

===Nuclear power plant===
[[File:Worldwide Nuclear Power Capacity Factors.png|thumb|Worldwide nuclear power capacity factors]]

Nuclear power plants are at the high end of the range of capacity factors, ideally reduced only by the [[Engineering:Availability factor|availability factor]], i.e. maintenance and refueling. The largest nuclear plant in the US, Palo Verde Nuclear Generating Station, has between its three reactors a nameplate capacity of {{val|3,942|u=MW}}. In 2010 its annual generation was {{val|31,200,000|u=MWh}},<ref>{{cite web |url=https://www.eia.gov/nuclear/state/arizona/ |website=eia.gov |title=Arizona Nuclear Profile 2010 |access-date=2017-02-11}}</ref> leading to a capacity factor of
<math display="block">
 \frac{31\,200\,000\ \text{MW}{\cdot}\text{h}}{(365\ \text{days}) \times (24\ \text{hours/day}) \times (3942\ \text{MW})} = 0.904 = 90.4\%.
</math>

Each of Palo Verde’s three reactors is refueled every 18 months, with one refueling every spring and fall. In 2014, a refueling was completed in a record 28 days,<ref>{{cite news |url=https://www.aps.com/en/ourcompany/news/latestnews/Pages/palo-verde-unit-2-ranked-as-top-us-generator-for-2013.aspx |title=Palo Verde unit 2 ranked as top U.S. generator for 2013 |website=[[Company:Arizona Public Service|Arizona Public Service]] |date=2014-03-10 |archive-url=https://web.archive.org/web/20150420141153/https://www.aps.com/en/ourcompany/news/latestnews/Pages/palo-verde-unit-2-ranked-as-top-us-generator-for-2013.aspx |archive-date=2015-04-20 |access-date=2017-02-11 |url-status=dead}}</ref> compared to the 35 days of downtime that the 2010 capacity factor corresponds to.<!-- 365 days * (1 - 0.904) = 35.0 days -->

In 2019, Prairie Island 1 was the US unit with the highest factor and actually reached 104.4%.<ref>{{cite web |url=https://www.world-nuclear.org/Information-Library/Facts-and-Figures/Reactor-Database.aspx |title=Reactor Database. Top load factor table |website=World Nuclear Association |date=2020-08-15}}</ref>

===Wind farm===
The Danish offshore wind farm Horns Rev 2 has a nameplate capacity of 209.3&nbsp;MW.
{{Asof|January 2017}} it has produced 6416&nbsp;GWh since its commissioning 7&nbsp;years ago, i.e. an average annual production of 875&nbsp;GWh/year<!-- age with only 2 digits, so annual production rounded (to 25), with higher precision the sourced numbers do not match up perfectly --> and a capacity factor of<ref name=HR2el>{{cite web |url=http://www.energynumbers.info/capacity-factors-at-danish-offshore-wind-farms |website=energynumbers.info |title=Capacity factors at Danish offshore wind farms |author=Andrew |date=2017-01-26 |access-date=2017-02-11 |archive-url=https://web.archive.org/web/20170129043234/http://energynumbers.info/capacity-factors-at-danish-offshore-wind-farms |archive-date=2017-01-29 |url-status=dead }}</ref>
<math display="block">
 \frac{875\,000\ \text{MW}{\cdot}\text{h}}{(365\ \text{days}) \times (24\ \text{hours/day}) \times (209.3\ \text{MW})} = 0.477 = 47.7\%.
</math>

Sites with lower capacity factors may be deemed feasible for wind farms, for example, the onshore 1&nbsp;GW Fosen Vind, which {{asof|2017|lc=yes}} is under construction in Norway, has a projected capacity factor of 39%. Feasibility calculations may be affected by seasonality. For example, in Finland, capacity factor during the cold winter months is more than double compared to July.<ref name="wind_fi_capa">{{cite web |last1=Huotari |first1=Jussi |title=Wind Power Generation Efficiency and Seasonality |date=2020 |url=https://www.jussihuotari.com/randstan/demo_wind/wind_seasonality_report.html |access-date=11 December 2020}}</ref> While the annual average in Finland is 29.5%,<ref name="wind_fi_capa"/> the high demand for heating energy correlates with the higher capacity factor during the winter.

Certain onshore wind farms can reach capacity factors of over 60%, for example, the 44&nbsp;MW Eolo plant in Nicaragua had a net generation of 232.132&nbsp;GWh in 2015, equivalent to a capacity factor of 60.2%,<ref>{{cite web
|url=http://www.cndc.org.ni/ftp2/descargar_ftp.php?dir=Comercial/Resumenes%20Anuales/2015//&nombre=RESUMEN%20INYECCIONES%202015.zip
|access-date=2016-07-29
|title=Centro Nacional de Despacho de Carga
|archive-date=2022-09-29
|archive-url=https://web.archive.org/web/20220929180255/https://www.cndc.org.ni/ftp2/descargar_ftp.php?dir=Comercial/Resumenes%20Anuales/2015//&nombre=RESUMEN%20INYECCIONES%202015.zip
|url-status=dead
}}</ref> while United States annual capacity factors from 2013 through 2016 range from 32.2% to 34.7%.<ref>{{Cite web |url=https://www.eia.gov/electricity/monthly/epm_table_grapher.cfm?t=epmt_6_07_b |title=Electricity Data |website=EIA |language=en |access-date=2017-04-10}}</ref>

Since the capacity factor of a wind turbine measures actual production relative to possible production, it is unrelated to Betz's coefficient of {{nobr|16/27 ≈ 59.3%}}, which limits production vs. energy available in the wind.

===Hydroelectric dam===
{{Asof|2017}} Three Gorges Dam in China is, with its nameplate capacity of 22,500&nbsp;MW, the largest power generating station in the world by installed capacity. 
In 2015 it generated 87&nbsp;TWh, for a capacity factor of
<math display="block">
 \frac{87\,000\,000\ \text{MW}{\cdot}\text{h}}{(365\ \text{days}) \times (24\ \text{hours/day}) \times (22\,500\ \text{MW})} = 0.45 = 45\%.
</math>

[[Engineering:Hoover Dam|Hoover Dam]] has a nameplate capacity of 2080 MW<ref name="hoover_dam_faq">{{Cite web
 |url          = http://www.usbr.gov/lc/hooverdam/faqs/powerfaq.html
 |title        = Hoover Dam – Frequently Asked Questions and Answers
 |publisher    = United States Bureau of Reclamation
 |access-date  = 2010-08-07
 |date         = February 2009
 |archive-url  = https://web.archive.org/web/20100323052336/http://www.usbr.gov/lc/hooverdam/faqs/powerfaq.html
 |archive-date = 2010-03-23
 |url-status   = dead
}}</ref> and an annual generation averaging 4.2&nbsp;TW·h.<ref name="hoover_dam_faq"/> (The annual generation has varied between a high of 10.348&nbsp;TW·h in 1984, and a low of 2.648&nbsp;TW·h in 1956.<ref name="hoover_dam_faq"/>)
Taking the average figure for annual generation gives a capacity factor of
<math display="block">
 \frac{4\,200\,000\ \text{MW}{\cdot}\text{h}}{(365\ \mbox{days}) \times (24\ \mbox{hours/day}) \times (2080\ \mbox{MW})} = 0.23 = 23\%.
</math>

===Photovoltaic power station===
At the low range of capacity factors is the [[Physics:Photovoltaic power station|photovoltaic power station]], which supplies power to the electricity grid from a large-scale [[Physics:Photovoltaic system|photovoltaic system]] (PV system). 
An inherent limit to its capacity factor comes from its requirement of [[Physics:Daylight|daylight]], preferably with a sun unobstructed by clouds, smoke or [[Earth:Smog|smog]], shade from trees and building structures. 
Since the amount of sunlight varies both with the time of the day and the seasons of the year, the capacity factor is typically computed on an annual basis. 
The amount of available sunlight is mostly determined by the [[Earth:Latitude|latitude]] of the installation and the local cloud cover.
The actual production is also influenced by local factors such as dust and ambient temperature, which ideally should be low. As for any power station, the maximum possible power production is the nameplate capacity times the number of hours in a year, while the actual production is the amount of electricity delivered annually to the grid.

For example, Agua Caliente Solar Project, located in Arizona near the 33rd parallel and awarded for its excellence in renewable energy has a nameplate capacity of 290&nbsp;MW and an actual average annual production of 740&nbsp;GWh/year.
Its capacity factor is thus
<math display="block">
 \frac{740\,000\ \text{MW}{\cdot}\text{h}}{(365\ \text{days}) \times (24\ \text{hours/day}) \times (290\ \text{MW})} = 0.291 = 29.1\%.
</math>

A significantly lower capacity factor is achieved by Lauingen Energy Park located in Bavaria, near the 49th parallel. With a nameplate capacity of 25.7&nbsp;MW and an actual average annual production of 26.98&nbsp;GWh/year it has a capacity factor of 12.0%.

== Determinants of a plant capacity factor ==
There are several reasons why a plant would have a capacity factor lower than 100%. These include technical constraints, such as [[Operational availability|operational availability]] <math display="inline">A_o</math> of the plant (known as [[Engineering:Availability factor|availability factor]] for electricity generators), economic reasons, and availability of an energy resource.

A plant can be out of service or operating at reduced output for part of the time due to equipment failures or routine  maintenance. 
This accounts for most of the unused capacity of base load power plants. Base load plants usually have low costs per unit of electricity because they are designed for maximum efficiency and are operated continuously at high output.
Geothermal power plants, [[Engineering:Nuclear power plant|nuclear power plant]]s, coal-fired plants and bioenergy plants that burn solid material are almost always operated as base load plants, as they can be difficult to adjust to suit demand.

A plant can also have its output curtailed or intentionally left idle because the electricity is not needed or because the price of electricity is too low to make production economical.
This accounts for most of the unused capacity of [[Engineering:Peaking power plant|peaking power plant]]s and [[Engineering:Load following power plant|load following power plant]]s.
Peaking plants may operate for only a few hours per year or up to several hours per day.
Many other power plants operate only at certain times of the day or year because of variation in loads and electricity prices.
If a plant is only needed during the day, for example, even if it operates at full power output from 8 am to 8 pm every day (12 hours) all year long, it would only have a 50% capacity factor.
Due to low capacity factors, electricity from peaking power plants is relatively expensive because the limited generation has to cover the plant fixed costs.

A third reason is that a plant may not have the fuel available to operate all of the time. 
This can apply to fossil generating stations with restricted fuels supplies, but most notably applies to intermittent renewable resources.<ref name=ieaCF2015>{{cite web|title=Electric generator capacity factors vary widely across the world - Today in Energy - U.S. Energy Information Administration (EIA)|url=https://www.eia.gov/todayinenergy/detail.php?id=22832 |website=www.eia.gov|access-date=13 April 2017|language=en}}</ref>
Solar PV and wind turbines have a capacity factor limited by the availability of their "fuel", sunshine and wind respectively.
A hydroelectricity plant may have a capacity factor lower than 100% due to restriction or scarcity of water, or its output may be regulated to match the current power need, conserving its stored water for later usage.

Governments differ in their wiliness to accept risks of power outages and lack of [[Engineering:Resilience (engineering and construction)|resilience]] against natural disasters and military attack on electricity grids. Examples of historical events impacting grid resilience are the 1991 Gulf War air campaign against civilian infrastructure, 2015 Ukraine power grid hack, 2021 Texas power crisis and Russian strikes against Ukrainian infrastructure (2022–present). Low risk tolerance may require electricity grids to be more significantly overbuilt to mitigate the potential costs of electricity grid interruptions and outages, impacting on a technology-by-technology basis the amount of generation curtailment necessary under normal grid conditions.

Other reasons that a power plant may not have a capacity factor of 100% include restrictions or limitations on air permits and limitations on transmission that force the plant to curtail output.

== Capacity factor of renewable energy ==
[[File:US EIA monthly capacity factors for renewables 2011-2013.png|framed|right|[[Energy Information Administration|US EIA]] monthly capacity factors for renewables, 2011-2013]]
For [[Engineering:Renewable energy|renewable energy]] sources such as [[Engineering:Solar power|solar power]], wind power and hydroelectricity, the main reason for reduced capacity factor is generally the availability of the energy source. 
The plant may be capable of producing electricity, but its "fuel" ([[Earth:Wind|wind]], [[Astronomy:Sunlight|sunlight]] or [[Chemistry:Water|water]]) may not be available. 
A hydroelectric plant's production may also be affected by requirements to keep the water level from getting too high or low and to provide water for [[Biology:Fish|fish]] downstream. 
However, solar, wind and hydroelectric plants do have high [[Engineering:Availability factor|availability factor]]s, so when they have fuel available, they are almost always able to produce electricity.<ref>[http://www.awea.org/faq/basicen.html How Does A Wind Turbine's Energy Production Differ from Its Power Production?] {{webarchive |url=https://web.archive.org/web/20080313142528/http://www.awea.org/faq/basicen.html |date=March 13, 2008 }}</ref>

When hydroelectric plants have water available, they are also useful for load following, because of their high ''dispatchability''. A typical hydroelectric plant's operators can bring it from a stopped condition to full power in just a few minutes.

Wind farms are variable, due to the natural variability of the wind. 
For a wind farm, the capacity factor is determined by the availability of wind, the swept area of the turbine and the size of the [[Engineering:Electric generator|generator]]. 
Transmission line capacity and electricity demand also affect the capacity factor. 
Typical capacity factors of current wind farms are between 25 and 45%.<ref>{{cite news|url= http://cleantechnica.com/2015/08/04/wind-could-replace-coal-as-us-primary-generation-source-new-nrel-data-suggests |website= cleantechnica.com |title= Wind Could Replace Coal As US' Primary Generation Source, New NREL Data Suggests |first= Clayton |last= Handleman |date= 2015-08-04 |access-date= 2017-02-11}}</ref> In the United Kingdom during the five year period from 2011 to 2019 the annual capacity factor for wind was over 30%.<ref name="decc.gov.uk">{{cite web|url=http://www.decc.gov.uk/assets/decc/11/stats/publications/dukes/5956-dukes-2012-chapter-6-renewable.pdf|title=Digest of United Kingdom energy statistics (DUKES) for 2012: chapter 6 - Renewable sources of energy|website=decc.gov.uk|access-date=20 March 2018|archive-date=30 October 2012|archive-url=https://web.archive.org/web/20121030181415/http://www.decc.gov.uk/assets/decc/11/stats/publications/dukes/5956-dukes-2012-chapter-6-renewable.pdf|url-status=dead}}</ref><ref name="www.gov.uk">{{cite web|url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/279547/DUKES_2013_Chapter_6.pdf|title=Digest of United Kingdom energy statistics (DUKES) for 2013: chapter 6 - Renewable sources of energy|website=www.gov.uk|access-date=20 March 2018}}</ref><ref name="www.gov.uk1">{{cite web|url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/337684/chapter_6.pdf|title=Digest of United Kingdom energy statistics (DUKES) for 2014: chapter 6 - Renewable sources of energy|website=www.gov.uk|access-date=20 March 2018}}</ref><ref name="www.gov.uk2">{{cite web|url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/547977/Chapter_6_web.pdf|title=Digest of United Kingdom energy statistics (DUKES) for 2016: chapter 6 - Renewable sources of energy|website=www.gov.uk|access-date=20 March 2018}}</ref>

[[Physics:Solar energy|Solar energy]] is variable because of the daily rotation of the earth, seasonal changes, and because of cloud cover. 
For example, the Sacramento Municipal Utility District observed a 15% capacity factor in 2005.<ref name=Blees2008>{{cite book |ref=Blees2008 | author=Tom Blees | title=Prescription for the Planet |url=https://archive.org/details/isbn_9781419655821 |url-access=registration | isbn=978-1-4196-5582-1 | year=2008| publisher=BookSurge }}</ref>
However, according to the SolarPACES programme of the [[Organization:International Energy Agency|International Energy Agency]] (IEA), solar power plants designed for solar-only generation are well matched to summer noon peak loads in areas with significant cooling demands, such as Spain or the south-western United States,<ref name=mangey/> although in some locations solar PV does not reduce the need for generation of network upgrades given that air conditioner peak demand often occurs in the late afternoon or early evening when solar output is reduced.<ref>Muriel Watt [http://www.ergo.ee.unsw.edu.au/value%20of%20PV%20in%20summer%20peaks.pdf Value of PV in summer peaks] {{webarchive |url=https://web.archive.org/web/20110217093812/http://www.ergo.ee.unsw.edu.au/value%20of%20PV%20in%20summer%20peaks.pdf |date=February 17, 2011 }}</ref><ref>Government of South Australia (2007), p.13,14 [http://www.climatechange.sa.gov.au/uploads/pdf/Feed-in_Discussion_Paper_submissions_closed.pdf South Australia’s Feed-In Mechanism for Residential Small-Scale Solar Photovoltaic Installations] {{webarchive |url=https://web.archive.org/web/20101205013241/http://www.climatechange.sa.gov.au/uploads/pdf/Feed-in_Discussion_Paper_submissions_closed.pdf |date=December 5, 2010 }}</ref> 
SolarPACES states that by using thermal energy storage systems the operating periods of solar thermal power (CSP) stations can be extended to become dispatchable (load following).<ref name=mangey>Thomas R. Mancini and Michael Geyer (2006). [http://www.iea.org/impagr/cip/pdf/issue36SolarP.pdf Spain Pioneers Grid-Connected Solar-Tower Thermal Power] {{Webarchive|url=https://web.archive.org/web/20180927165254/https://www.iea.org/impagr/cip/pdf/issue36SolarP.pdf |date=2018-09-27 }} SolarPACES, OECD/ IEA, p. 3.</ref>

[[Earth:Geothermal power|Geothermal]] has a higher capacity factor than many other power sources, and geothermal resources are generally available all the time.

==Capacity factors by energy source==

=== Worldwide ===

*Nuclear power 88.7% (2006–2012 average of US's plants).<ref name="ModernNucCapacity">{{cite web |title=United States Nuclear Capacity Factors |url=http://www.nei.org/Knowledge-Center/Nuclear-Statistics/US-Nuclear-Power-Plants/US-Nuclear-Capacity-Factors |access-date=2013-10-26 |work=Nuclear Energy Institute}}</ref>
* Hydroelectricity, worldwide average 44%,<ref>[https://web.archive.org/web/20120524071136/http://srren.ipcc-wg3.de/report/IPCC_SRREN_Ch05.pdf Hydropower], p. 441.</ref> range of 10–99% depending on water availability (with or without regulation via storage dam).
* Wind farms 21–52% (as of 2022).<ref>{{cite web |title=Wind Energy Factsheet |url=https://css.umich.edu/publications/factsheets/energy/wind-energy-factsheet |website=Center for Sustainable Systems |access-date=23 September 2024 |language=en}}</ref>
* CSP solar with storage and Natural Gas backup in Spain 63%,<ref name="CSPStorageCapacity">{{cite web |title=Torresol Energy Gemasolar Thermosolar Plant |url=http://www.torresolenergy.com/TORRESOL/gemasolar-plant/en |access-date=2014-03-12 |archive-date=2014-02-20 |archive-url=https://web.archive.org/web/20140220040106/http://www.torresolenergy.com/TORRESOL/gemasolar-plant/en |url-status=dead}}</ref> California 33%.<ref name="CSPCapacity">{{cite web |title=Ivanpah Solar Electric Generating Station |url=http://www.nrel.gov/csp/solarpaces/project_detail.cfm/projectID=62 |url-status=dead |archive-url=https://web.archive.org/web/20151012092620/http://www.nrel.gov/csp/solarpaces/project_detail.cfm/projectID=62 |archive-date=2015-10-12 |access-date=2012-08-27 |work=National Renewable Energy Laboratory}}</ref>
* Photovoltaic solar in Germany 10%, Arizona 19%,<ref>{{cite web |date=15 October 2013 |title=Low Capacity Factors: challenges for a low carbon energy transition |url=http://www.theenergycollective.com/robertwilson190/288846/low-capacity-factors-challenge-low-carbon-energy-transition |access-date=20 March 2018 |website=The Energy Collective}}</ref><ref name="THSolarVsWind">{{cite web |last=Laumer |first=John |date=June 2008 |title=Solar Versus Wind Power: Which Has The Most Stable Power Output?|url=http://www.treehugger.com/files/2008/03/solar-versus-wind-power.php|access-date=2008-10-16|work=Treehugger |archive-date=2008-10-20 |archive-url=https://web.archive.org/web/20081020231207/http://www.treehugger.com/files/2008/03/solar-versus-wind-power.php |url-status=dead}}</ref><ref name="Arni">{{Cite conference |last=Ragnarsson |first=Ladislaus |url=http://iga.igg.cnr.it/documenti/IGA/Fridleifsson_et_al_IPCC_Geothermal_paper_2008.pdf |title=The possible role and contribution of geothermal energy to the mitigation of climate change |author2=Rybach |date=2008-02-11 |editor=O. Hohmeyer and T. Trittin |location=Luebeck, Germany |pages=59–80 |access-date=2009-04-06 |archive-url=https://web.archive.org/web/20110722030340/http://iga.igg.cnr.it/documenti/IGA/Fridleifsson_et_al_IPCC_Geothermal_paper_2008.pdf |archive-date=2011-07-22 |url-status=dead |conference=IPCC Scoping Meeting on Renewable Energy Sources}}</ref> Massachusetts 13.35% (8 year average as of July 2018).<ref>SREC Capacity Factor Report, https://www.masscec.com/data-and-reports</ref>

===United States===
According to the US Energy Information Administration (EIA), from 2013 to 2017 the capacity factors of utility-scale generators were as follows:<ref>{{cite web |url=https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_6_07_a |title=Table 6.7.B. Capacity Factors for Utility Scale Generators Primarily Using Fossil Fuels |access-date=21 Aug 2018}}<br/>{{cite web |url=https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_6_07_b |title=Table 6.7.B. Capacity Factors for Utility Scale Generators Not Primarily Using Fossil Fuels |access-date=21 Aug 2018}}</ref>
{{scrolling table/top|first=Year
|&nbsp;<br/>&nbsp;
|2013
|2014
|2015
|2016
|2017
|2018}}
{{scrolling table/mid}}
|-
!colspan="8"| Non-fossil fuels !! Coal !!colspan="4"| Natural gas !!colspan="3"| Petroleum liquids
|-
!Nuclear !! {{abbr|Conv.|Conventional}} Hydro !! Wind !! Solar PV !! Solar [[Engineering:Concentrated solar power|CSP]] !! Landfill gas <br/> and {{abbr|MSW|municipal solid saste}} !! Other biomass,<br/> including wood !! Geothermal !! !! {{abbr|CC|Combined cycle}} !! {{abbr|CT|Combustion turbine}} !! {{abbr|ST|Steam turbine}} !! {{abbr|ICE|Internal combustion engine}} !! {{abbr|ST|Steam turbine}} !! {{abbr|CT|Combustion turbine}} !! {{abbr|ICE|Internal combustion engine}}
|-
|89.9% ||38.9% ||32.4% ||NA ||NA ||68.9% ||56.7% ||73.6% ||59.8% ||48.2% ||4.9% ||10.6% ||6.1% ||12.1% ||0.8% ||2.2%
|-
|91.7% ||37.3% ||34.0% ||25.9% ||19.8% ||68.9% ||58.9% ||74.0% ||61.1% ||48.3% ||5.2% ||10.4% ||8.5% ||12.5% ||1.1% ||1.4%
|-
|92.3% ||35.8% ||32.2% ||25.8% ||22.1% ||68.7% ||55.3% ||74.3% ||54.7% ||55.9% ||6.9% ||11.5% ||8.9% ||13.3% ||1.1% ||2.2%
|-
|92.3% ||38.2% ||34.5% ||25.1% ||22.2% ||69.7% ||55.6% ||73.9% ||53.3% ||55.5% ||8.3% ||12.4% ||9.6% ||11.5% ||1.1% ||2.6%
|-
|92.2% ||43.1% ||34.6% ||25.7% ||21.8% ||68.0% ||57.8% ||74.0% ||53.7% ||51.3% ||6.7% ||10.5% || 9.9% ||13.5% ||0.9% || 2.3% 
|-
|92.6% ||42.8% ||37.4% ||26.1% ||23.6% ||73.3% ||49.3% ||77.3% ||54.0% ||57.6% ||11.8% ||13.7% ||NA ||13.9% ||2.5% ||NA 
{{scrolling table/end}}

However, these values often vary significantly by month.

===United Kingdom===
The following figures were collected by the Department of Energy and Climate Change on the capacity factors for various types of plants in UK grid:<ref>{{cite web |url=http://www.decc.gov.uk/assets/decc/11/stats/publications/dukes/5955-dukes-2012-chapter-5-electricity.pdf |title=Digest of United Kingdom energy statistics (DUKES) for 2012: Chapter 5 – Electricity |website=Department of Energy & Climate Change |access-date=20 March 2018 |archive-date=30 October 2012 |archive-url=https://web.archive.org/web/20121030181636/http://www.decc.gov.uk/assets/decc/11/stats/publications/dukes/5955-dukes-2012-chapter-5-electricity.pdf |url-status=dead}}</ref><ref name="decc.gov.uk"/><ref>{{cite web |url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/279546/DUKES_2013_Chapter_5.pdf |title=Digest of United Kingdom energy statistics (DUKES) for 2013: Chapter 5 – Electricity |website=GOV.UK |access-date=20 March 2018}}</ref><ref name="www.gov.uk"/><ref>{{cite web |url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/337649/chapter_5.pdf |title=Digest of United Kingdom energy statistics (DUKES) for 2014: Chapter 5 – Electricity |website=GOV.UK |access-date=20 March 2018 |archive-date=31 May 2015 |archive-url=https://web.archive.org/web/20150531215731/https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/337649/chapter_5.pdf |url-status=dead}}</ref><ref name="www.gov.uk1"/><ref>{{cite web |url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/552059/Chapter_5_web.pdf |title=Digest of United Kingdom energy statistics (DUKES) for 2016: Chapter 5 – Electricity |website=GOV.UK |access-date=20 March 2018}}</ref><ref name="www.gov.uk2"/><ref>{{cite web |url=https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/904815/DUKES_5.10.xls |title=Digest of United Kingdom energy statistics (DUKES) for 2020: Chapter 5 – Electricity |website=GOV.UK |access-date=21 October 2020}}</ref><ref>{{cite web |url=https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/904826/DUKES_6.5.xls |title=Digest of United Kingdom energy statistics (DUKES) for 2020: Chapter 6 – Renewable sources of energy |website=GOV.UK |access-date=21 October 2020}}</ref>

{| class="wikitable sortable"
! Generator type 
!  2007 !!  2008 !!  2009 !!  2010 !!  2011 !!  2012 !!  2013 !!  2014 !!  2015 !!  2016 !!  2017 !!  2018 !!  2019 !!  2020 !!  2021
|-
| Nuclear power stations
| 59.6% || 49.4% || 65.6% || 59.3% || 66.4% || 70.8% || 73.8% || 66.6% || 75.1% || 80.1% || 78.8% || 72.9% || 62.9% || 59.8% || 58.5%
|-
| Combined cycle gas turbine stations
| 64.7% || 71.0% || 64.2% || 61.6% || 47.8% || 30.3% || 27.9% || 30.5% || 32.1% || 49.8% || 45.5% || 42.7% || 43.0% || 35.4% || 38.9%
|-
| Coal-fired power stations
| 46.7% || 45.0% || 38.5% || 40.2% || 40.8% || 56.9% || 58.1% || 50.7% || 44.0% || 21.2% || 17.3% || 14.2% ||  7.8% ||  9.7% || 12.7%
|-
| Hydroelectric power stations
| 38.2% || 37.4% || 36.7% || 24.9% || 39.0% || 35.7% || 31.6% || 39.1% || 41.0% || 34.0% || 36.3% || 33.2% || 36.1% || 41.5% || 33.1%
|-
| Wind power
| 27.7% || 27.5% || 27.1% || 23.7% || 30.1% || 29.4% || 32.2% || 30.1% || 33.6% || 27.8% || 31.7% || 31.5% || 32.0% || 35.6% || 29.3%
|-
| style="padding-left: 2em;" | Offshore wind power
| 25.6% || 30.7% || 25.9% || 30.5% || 37.0% || 35.8% || 39.1% || 37.3% || 41.5% || 36.0% || 38.9% || 39.9% || 40.4% || 45.7% || 37.4%
|-
| [[Physics:Photovoltaic power station|Photovoltaic power station]]s
|  9.9% ||  9.6% ||  9.3% ||  7.3% ||  5.1% || 11.2% ||  9.9% || 11.1% || 11.8% || 11.0% || 10.6% || 11.2% || 10.7% || 10.9% || 10.0%
|-
| Marine ([[Physics:Wave power|wave]] and [[Astronomy:Tidal power|tidal power]] stations)
|  0.4% ||  0.8% ||  4.8% ||  8.4% ||  3.8% ||  8.3% ||  9.6% ||  3.2% ||  2.6% ||  0.0% ||  3.0% ||  5.5% ||  7.5% ||  5.7% ||  2.8%
|-
| [[Biology:Bioenergy|Bioenergy power stations]]
| 52.7% || 52.2% || 56.5% || 55.2% || 44.1% || 46.9% || 56.8% || 60.1% || 67.4% || 61.8% || 61.5% || 58.6% || 55.4% || 56.7% || 56.6%
|}

== See also ==
* [[Engineering:Demand factor|Demand factor]]
* Intermittent power source

==References==
{{Reflist}}

{{Electricity generation}}

[[Category:Power station technology]]

{{Sourceattribution|Capacity factor}}