Base load

{{short description|Minimum level of demand on an electrical grid over a span of time}} [[File:Metsamor_NPP_aerial_view_1_cropped.jpg|thumb|Some early nuclear plants, such as the VVER-440 (pictured at Metsamor) were designed for baseload operation <ref>{{Cite journal |title=Review of solutions developed for improving maneuvering flexibility in German, French and Russian PWRs targeting to explore future possibilities for the new VVER-1200 nuclear power plant units in Hungary |doi=10.1016/j.nucengdes.2024.112965 |bibcode=2024NuEnD.41912965S |last1=Szondy |first1=Borbála |last2=Bodnár |first2=Balázs |last3=Grossetête |first3=Alain |last4=Gain |first4=Thibaut |last5=Aszódi |first5=Attila |journal=Nuclear Engineering and Design |date=2024 |volume=419 |article-number=112965 |doi-access=free }}</ref>]] The '''base load'''<ref name="baseload">{{Cite web|url=https://www.merriam-webster.com/dictionary/baseload|title=Definition of "baseload"|website=www.merriam-webster.com|publisher=Merriam Webster Dictionary|language=en|access-date=2018-12-02}}</ref> (also '''baseload''') is the minimum level of demand on an electrical grid over a span of time, for example, one week. This demand can be met by unvarying power plants<ref name="fink78" /> or dispatchable generation,<ref name="pembina"/> depending on which approach has the best mix of cost, availability and reliability in any particular market. The remainder of demand, varying throughout a day, is met by intermittent sources together with dispatchable generation (such as load following power plants, peaking power plants, which can be turned up or down quickly) or energy storage.

Power plants that do not change their power output quickly, such as some large coal or nuclear plants, are generally called '''baseload power plants'''.<ref name="fink78">Donald G. Fink, H. Wayne Beatty (ed), ''Standard Handbook for Electrical Engineers'', Eleventh Edition, Mc-Graw Hill, 1978 {{ISBN|9780070209749}}, pp. 12-16 through 12-18</ref><ref name="vortex">{{cite web |url= http://www.energyvortex.com/energydictionary/baseload_plant.html |title= Energy Dictionary - Baseload plant |publisher= EnergyVortex.com |access-date= 2008-08-03 |archive-date= 2009-02-15 |archive-url= https://web.archive.org/web/20090215035802/http://www.energyvortex.com/energydictionary/baseload_plant.html |url-status= dead }}</ref><ref name=":0">{{Cite web|last1=July 10|last2=Alum|first2=2017 Kevin Steinberger-Alum Miles Farmer-|title=Debunking Three Myths About "Baseload"|url=https://www.nrdc.org/experts/kevin-steinberger/debunking-three-myths-about-baseload|access-date=2022-01-29|website=NRDC|date=10 July 2017 |language=en}}</ref> In the 20th century most or all of base load demand was met with baseload power plants,<ref>{{Cite web |date=2023-08-02 |title=The Baseload Fallacy |url=https://www.energyglobal.com/special-reports/02082023/the-baseload-fallacy/ |access-date=2024-04-07 |website=Energy Global |language=en}}</ref> whereas new capacity based around renewables often employs flexible generation.<ref name=holliday/>

==Description== Grid operators take long and short term bids to provide electricity over various time periods and balance supply and demand continuously.<ref name="ibrd">{{Cite book |url=http://www-wds.worldbank.org/external/default/WDSContentServer/WDSP/IB/2011/08/18/000356161_20110818032547/Rendered/PDF/638750PUB0Exto00Box0361531B0PUBLIC0.pdf |title=Electricity Auctions: An Overview of Efficient Practices |last=Maurer |first=Luiz T.A., Luiz A. Barroso |year=2011 |publisher=World Bank Publications |isbn=978-0-8213-8822-8}}</ref> The detailed adjustments are known as the unit commitment problem in electrical power production.{{citation needed|date=October 2022}}

While historically large power grids used unvarying power plants to meet the base load, there is no specific technical requirement for this to be so. The base load can equally well be met by the appropriate quantity of intermittent power sources and dispatchable generation.<ref name="pembina">{{Cite web |url=https://www.pembina.org/reports/TheBasicsOnBaseload.pdf |title=The Basics on Base Load: Meeting Ontario's Base Load Electricity Demand with Renewable Power Sources |last=Peters |first=Roger, Cherise Burda |date=2007-09-01 |website=Pembina Institute |access-date=2018-05-16}}</ref><ref name="stanford">{{Cite journal |last1=Archer |first1=Cristina L. |last2=Jacobson |first2=Mark Z. |date=November 2007 |title=Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms |journal=Journal of Applied Meteorology and Climatology |language=EN |volume=46 |issue=11 |pages=1701–1717 |doi=10.1175/2007jamc1538.1 |bibcode=2007JApMC..46.1701A |issn=1558-8424|citeseerx=10.1.1.475.4620 | url=https://journals.ametsoc.org/downloadpdf/view/journals/apme/46/11/2007jamc1538.1.pdf }}</ref>

Unvarying power plants can be coal, nuclear, combined cycle plants, which may take several days to start up and shut down,<ref>{{Cite news|url=https://www.zdnet.com/article/why-baseload-power-is-doomed/|title=Why baseload power is doomed|last=Nelder|first=Chris|work=ZDNet|access-date=2018-12-02|language=en}}</ref> hydroelectric, geothermal,<ref>{{cite web |url=http://www.renewableenergyworld.com/articles/2007/10/scaling-geothermal-for-reliable-baseload-power-50159.html |title=Scaling Geothermal for Reliable Baseload Power |publisher=renewableenergyworld.com |date=2007-10-05 |access-date=2008-08-03 |archive-date=2018-07-01 |archive-url=https://web.archive.org/web/20180701030441/https://www.renewableenergyworld.com/articles/2007/10/scaling-geothermal-for-reliable-baseload-power-50159.html |url-status=dead }}</ref> biogas, and biomass.

The desirable attribute of dispatchability applies to some gas plants and hydroelectricity. Grid operators also use ''curtailment'' to shut plants out of the grid when their energy is not needed.<ref name="curt1">{{Cite journal |last1=Bird |first1=Lori |last2=Lew |first2=Debra|author2-link=Debra Lew |last3=Milligan |first3=Michael |last4=Carlini |first4=E. Maria |last5=Estanqueiro |first5=Ana |last6=Flynn |first6=Damian |last7=Gomez-Lazaro |first7=Emilio |last8=Holttinen |first8=Hannele |last9=Menemenlis |first9=Nickie |date=November 2016 |title=Wind and solar energy curtailment: A review of international experience |journal=Renewable and Sustainable Energy Reviews |volume=65 |pages=577–586 |doi=10.1016/j.rser.2016.06.082 |issn=1364-0321|doi-access=free |bibcode=2016RSERv..65..577B |hdl=10197/9090 |hdl-access=free }}</ref><ref name="curt2">{{Cite web |url=https://www.greentechmedia.com/articles/read/renewables-curtailment-in-california-and-the-midwest-what-can-we-learn-from#gs.93GvC=4 |title=Renewables Curtailment: What We Can Learn From Grid Operations in California and the Midwest |last=GIMON |first=ERIC, ROBBIE ORVIS AND SONIA AGGARWAL |date=2015-03-23 |website=Green Tech Media |access-date=2018-05-16}}</ref>

== Economics == thumb|Grids with high penetration of renewable energy sources generally need more flexible generation rather than baseload generation Grid operators solicit bids to find the cheapest sources of electricity over short and long term buying periods.<ref name="alj">{{Cite news |url=http://america.aljazeera.com/opinions/2014/5/electricity-auctionpricespowerbillsconsumers.html |title=OPINION: How electricity auctions are rigged to favor industry |last=Johnston |first=David Cay |date=2014-05-29 |work=Al Jazeera |access-date=2018-05-16}}</ref>

Traditionally, nuclear and coal plants had high fixed costs, high plant load factor<ref>{{Cite web |title=What is Generation Capacity? |url=https://www.energy.gov/ne/articles/what-generation-capacity |access-date=2022-06-18 |website=Energy.gov |language=en}}</ref> but low marginal costs.{{Citation needed|date=April 2024|reason=if the carbon price is high the marginal cost of burning coal will be high too}} On the other hand, peak load generators, such as natural gas, had low fixed costs, low plant load factor and high marginal costs.<ref>{{cite book |url=https://books.google.com/books?id=aF7lWf14H2EC&dq=hydro+base+load&pg=PA77 |title=Ontario Hydro at the Millennium: Has Monopoly's Moment Passed? |author=Ronald J. Daniels |publisher=Montreal and Kingston: McGill-Queen's University Press |year=1996 |access-date=2008-08-03|isbn=9780773514300 }}</ref>

Some coal and nuclear power plants do not change production to match power consumption demands since it is sometimes more economical to keep operating them at constant production levels than to reduce output during times of power price below marginal cost, and not all power plants are designed for it. The IEA has suggested that coal power plants should not run as baseload, because that emits a lot of carbon dioxide, which causes climate change.<ref>{{Cite web |date=2024-03-19 |title=Accelerating Just Transitions for the Coal Sector – Analysis |url=https://www.iea.org/reports/accelerating-just-transitions-for-the-coal-sector |access-date=2024-04-06 |website=IEA |language=en-GB}}</ref> Some nuclear power stations, such as those in France, are physically capable of being used as load following power plants and do alter their output, to some degree, to help meet varying demands.<ref>Nuclear Development, June 2011, page 10 from http://www.oecd-nea.org/</ref>{{Moved resource|date=November 2021}}<ref>{{Cite web|url=http://www.oecd-nea.org/ |title=Nuclear Development|website=www.oecd-nea.org|publisher=Nuclear Energy Agency|access-date=2018-12-02}}</ref>{{Moved resource|date=November 2021}}

Some combined-cycle plants usually fuelled by gas, can provide baseload power,<ref>{{Cite web |title=A user's guide to natural gas power plants |url=https://www.utilitydive.com/news/a-users-guide-to-natural-gas-power-plants/259104/ |access-date=2022-06-18 |website=Utility Dive |language=en-US}}</ref>{{Request quotation|date=April 2024|reason=surely this depends on carbon price}}{{Obsolete source|reason=not much carbon pricing in 2014|date=April 2024}} as well as being able to be cost-effectively cycled up and down to match more rapid fluctuations in consumption.

According to National Grid plc chief executive officer Steve Holliday in 2015, and others, baseload is "outdated".<ref name=holliday>{{cite web|url=http://www.energypost.eu/interview-steve-holliday-ceo-national-grid-idea-large-power-stations-baseload-power-outdated/ |archive-url= https://web.archive.org/web/20160910134728/http://www.energypost.eu/interview-steve-holliday-ceo-national-grid-idea-large-power-stations-baseload-power-outdated/ |title=Steve Holliday CEO National Grid: baseload is outdated |date=11 September 2015 |archive-date=10 September 2016 |author=Karel Beckman |work=EnergyPost.eu |access-date=6 October 2016 |url-status=usurped }}</ref><ref name=":0" /> By 2019, Steve Holliday had left his position as CEO of National Grid plc and went on the record to say that, "It’s hard to conceive that nuclear does not have an important role to play".<ref>{{cite web|url=https://www.nytimes.com/2019/01/07/business/energy-environment/wales-hitachi-nuclear-plant-jobs.html | title=For Wales, Nuclear Plant Would Mean New Jobs. For the U.K., It May Mean More.|date=7 January 2019|work=New York Times|author=Stanley Reed}}</ref>

==References== {{Reflist}}

==External links== *[https://web.archive.org/web/20050217095327/http://cipco.apogee.net/foe/fgdlbl.asp Base Load Power Plants - Fundamentals of Electricity] - Broken *[https://web.archive.org/web/20110519095631/http://energyalmanac.ca.gov/electricity/levelized_costs.html Levelized Costs of Electricity Production by Technology] - Broken *[https://web.archive.org/web/20060301061409/http://www.asktheenergydoctor.com/images/X7-Capacity.doc The Energy Resources and Economics Workbook (.doc)] - Broken

{{DEFAULTSORT:Base Load Power Plant}} Category:Power station technology