Curtailment (electricity)
{{Short description|Deliberate reduction in power output}}
{{other uses|Curtailment (disambiguation){{!}}Curtailment}}
In the electric power industry, curtailment is an involuntary reduction of the electric generator output ("dispatch down") made to maintain grid stability (for example, in grid balancing). While curtailment is a standard technique that has been applied throughout the history of electric power production, in the 21st century it has become an economic issue for the owners of wind and solar generation plants. These variable renewable energy plants, due to the absence of an expendable resource (like fuel), have quite low marginal electricity production costs, so curtailment affects the economics of projects in a much more significant way than with conventional units.{{sfn|Bird|Cochran|Wang|2014|p=iv}}
Curtailment is a loss of potentially useful energy and may impact power purchase agreements.{{cite web |title=How to Manage Curtailment in a Virtual Power Purchase Agreement |url=https://leveltenenergy.com/blog/ppa-risk-management/renewable-energy-curtailment/ |website=LevelTen Energy |archiveurl=https://web.archive.org/web/20200807214948/https://leveltenenergy.com/blog/ppa-risk-management/renewable-energy-curtailment/ |archivedate=7 August 2020 |date=13 February 2019 |url-status=live}}{{cite web |last1=St. John |first1=Jeff |title=Do Preventative Blackouts Put California's Renewable Generators at Risk? |url=https://www.greentechmedia.com/articles/read/understanding-the-risk-of-preventative-blackouts-for-californias-renewable- |website=www.greentechmedia.com |archiveurl=https://web.archive.org/web/20200810000404/https://www.greentechmedia.com/articles/read/understanding-the-risk-of-preventative-blackouts-for-californias-renewable- |archivedate=10 August 2020 |date=26 November 2019 |quote=PG&E will effectively shut down projects during public safety power shutoff (PSPS) events, and then not pay the developer for the lost production |url-status=live}} However, using all available energy may require costly methods such as building new power lines or storage, becoming more expensive than letting surplus power go unused.{{cite web |last1=Specht |first1=Mark |title=Renewable Energy Curtailment 101: The Problem That's Actually Not a Problem At All |url=https://blog.ucsusa.org/mark-specht/renewable-energy-curtailment-101 |website=Union of Concerned Scientists |archiveurl=https://web.archive.org/web/20200901201611/https://blog.ucsusa.org/mark-specht/renewable-energy-curtailment-101 |archivedate=1 September 2020 |date=25 June 2019 |quote=In most cases, it simply does not make economic sense to build all the infrastructure (e.g. transmission lines or energy storage) that would be required to utilize every last drop of renewable electricity |url-status=live}}{{cite web |last1=Elliott |first1=Dave |title=Curtailment: losing green power |url=https://physicsworld.com/a/curtailment-losing-green-power/ |website=Physics World |archiveurl=https://web.archive.org/web/20200807214948/https://leveltenenergy.com/blog/ppa-risk-management/renewable-energy-curtailment/ |archivedate=7 August 2020 |date=10 July 2019 |url-status=live}}{{Cite web |url=http://www.powermarkets.org/uploads/4/7/9/3/47931529/calif_curtailment_as_published.pdf |title=Archived copy |access-date=2020-10-22 |archive-date=2018-08-22 |archive-url=https://web.archive.org/web/20180822011304/http://www.powermarkets.org/uploads/4/7/9/3/47931529/calif_curtailment_as_published.pdf |url-status=dead }}{{cite web |title=Curtailment of low-cost renewables a cost-effective alternative to 'seasonal' energy storage |url=https://www.cleanpower.com/2019/curtailment-of-low-cost-renewables/ |website=Clean Power Research |archiveurl=https://web.archive.org/web/20200813210523/https://www.cleanpower.com/2019/curtailment-of-low-cost-renewables/ |archivedate=13 August 2020 |date=13 February 2019 |url-status=live}}
Examples
After ERCOT built a new transmission line from the Competitive Renewable Energy Zone in West Texas to the central cities in the Texas Interconnection in 2013, curtailment was reduced from 8-16% to near zero.Wiser, Ryan H., and Mark Bolinger. "[https://emp.lbl.gov/publications/2014-wind-technologies-ma 2014 Wind Technologies Market Report]" page 38. Lawrence Berkeley National Laboratory, August 2015.
Curtailment of wind power in western China was around 20% in 2018.{{cite web |last1=Fairley |first1=Peter |title=China's Ambitious Plan to Build the World's Biggest Supergrid |url=https://spectrum.ieee.org/chinas-ambitious-plan-to-build-the-worlds-biggest-supergrid |website=IEEE Spectrum |archive-url= https://web.archive.org/web/20210820021954/https://spectrum.ieee.org/chinas-ambitious-plan-to-build-the-worlds-biggest-supergrid |archive-date=20 August 2021 |language=en |date=21 February 2019 |url-status=live}}
In 2018, curtailment in the California grid was 460 GWh, or 0.2% of generation.{{cite web |last1=Victor |first1=David G. |title=Pumped Energy Storage: Vital to California's Renewable Energy Future |url=https://www.sdcwa.org/sites/default/files/White%20Paper%20-%20Pumped%20Energy%20Storage%20V.16.pdf |pages=4, 12–15 |date=21 May 2019}} Curtailment has since increased{{cite web |title=California ISO - Managing Oversupply |url=http://www.caiso.com/informed/Pages/ManagingOversupply.aspx |website=www.caiso.com |archiveurl= https://web.archive.org/web/20201014093030/http://www.caiso.com/informed/Pages/ManagingOversupply.aspx |archivedate=14 October 2020 |url-status=live}} to 150-300 GWh/month in spring of 2020 and 2021,{{cite web |last1=Hornyak |first1=Tim |title=An $11 trillion global hydrogen energy boom is coming. Here's what could trigger it |url=https://www.cnbc.com/2020/11/01/how-salt-caverns-may-trigger-11-trillion-hydrogen-energy-boom-.html |website=CNBC |archive-url= https://web.archive.org/web/20210520155551/https://www.cnbc.com/2020/11/01/how-salt-caverns-may-trigger-11-trillion-hydrogen-energy-boom-.html |archive-date=20 May 2021 |language=en |date=1 November 2020 |url-status=live}}{{cite web |last1=Aniti |first1=Lori |title=California's curtailments of solar electricity generation continue to increase - Today in Energy - U.S. Energy Information Administration (EIA) |url=https://www.eia.gov/todayinenergy/detail.php?id=49276 |website=www.eia.gov |archive-url= https://web.archive.org/web/20210825183847/https://www.eia.gov/todayinenergy/detail.php?id=49276 |archive-date=25 August 2021 |date=24 August 2021 |url-status=live}} mainly solar power at noon as part of the duck curve.
In Hawaii, curtailment reached 20% on the island of Maui in Hawaii in the second and third quarters of 2020.{{cite web |title=Renewable Energy |url=https://www.hawaiianelectric.com/about-us/key-performance-metrics/renewable-energy |website=www.hawaiianelectric.com |archive-url= https://web.archive.org/web/20210915100440/https://www.hawaiianelectric.com/about-us/key-performance-metrics/renewable-energy |archive-date=15 September 2021 |language=en |url-status=live}}
In Ireland, 1.2 TWh of wind power was curtailed in 2022.{{cite web |last1=Parkes |first1=Rachel |title=Wind-rich Ireland 'could make Europe's cheapest green hydrogen' |url=https://www.rechargenews.com/energy-transition/wind-rich-ireland-could-make-europes-cheapest-green-hydrogen/2-1-1415954 |website=rechargenews.com |language=en |date=8 March 2023}} In United Kingdom, 1.35 TWh of wind power was curtailed in early 2023.{{cite web |title=Orsted, Highview Power sign storage pact |url=https://renews.biz/84955/orsted-highview-power-sign-energy-storage-mou/ |website=reNEWS - Renewable Energy News |date=6 April 2023}} In Australia, 4.5 TWh of solar and wind power was curtailed in 2024.{{cite web |title=Snowy Hydro-worth of solar and wind wasted in 2024, as curtailment continues to bite |url=https://reneweconomy.com.au/snowy-hydro-worth-of-solar-and-wind-wasted-in-2024-as-curtailment-continues-to-bite/ |website=RenewEconomy |language=en-AU |date=4 February 2025}}
From October 2022 to September 2024, 2.9% of solar power in Spain was curtailed.{{cite web |last1=Molina |first1=Pilar Sanchez |title=Batteries with 200 Wh storage per kW of solar capacity could mitigate curtailment in Spain |url=https://www.ess-news.com/2025/07/01/batteries-with-200-wh-storage-per-kw-of-solar-capacity-could-mitigate-curtailment-in-spain/ |website=Energy Storage |date=1 July 2025}}
File:Wind power curtailment in USA, 2007-2014.svg|Curtailment in Texas
File:Monthly CAISO curtailments 2015-2021june.svg|Monthly curtailment in California
File:CAISO average hourly solar and curtailment 2020.svg|Solar power and curtailment in California, by hour
Mitigation options
- Transmission upgrade
- Demand response{{cite book |last1=Chelmis |first1=Charalampos |last2=Saeed |first2=Muhammad Rizwan |last3=Frincu |first3=Marc |last4=Prasanna |first4=Viktor |title=Proceedings of the 2015 ACM Sixth International Conference on Future Energy Systems |chapter=Curtailment Estimation Methods for Demand Response: Lessons Learned by Comparing Apples to Oranges |date=14 July 2015 |pages=217–218 |doi=10.1145/2768510.2775332 |isbn=9781450336093 |s2cid=16488954 |chapter-url=http://www.cs.albany.edu/~cchelmis/pubs/energy15b.pdf |access-date=9 November 2022 |language=en}}{{cite web |last1=Pyper |first1=Julia |title=Electric Ridesharing Benefits the Grid, and EVgo Has the Data to Prove It |url=https://www.greentechmedia.com/articles/read/electric-ridesharing-benefit-the-grid-evgo |website=www.greentechmedia.com |archiveurl=https://web.archive.org/web/20201018043438/https://www.greentechmedia.com/articles/read/electric-ridesharing-benefit-the-grid-evgo |archivedate=18 October 2020 |date=9 May 2019 |quote=the cumulative annual load profile by hour of LDV fleets using its fast charging network — with rideshare vehicles currently making up the lion’s share on a gigawatt-hour basis — aligns with the cumulative solar curtailment by hour on the CAISO system |url-status=live}}{{cite journal |last1=Zheng |first1=Jiajia |last2=Chien |first2=Andrew A. |author3-link=Sangwon Suh |last3=Suh |first3=Sangwon |title=Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers |journal=Joule |date=October 2020 |volume=4 |issue=10 |pages=2208–2222 |doi=10.1016/j.joule.2020.08.001 |s2cid=225188834 |quote= load migration within the existing data center capacity during the curtailment hours in CAISO has the potential to reduce 113–239 KtCO 2e per year of GHG emissions and absorb up to 62% of the total curtailment with negative abatement costs in 2019|doi-access=free }}
- Battery storage power station
- Energy forecasting, including forecasting for price, wind and solar
References
{{Reflist}}
Sources
- {{cite web| first1 = Lori | last1 = Bird | first2 = Jaquelin | last2 = Cochran | first3 = Xi | last3 = Wang |title=Wind and Solar Energy Curtailment: Experience and Practices in the United States
|url=https://docs.nrel.gov/docs/fy14osti/60983.pdf |ref= |date = March 2014 | publisher=NREL |access-date=2025-05-20}}
External links
- [https://www.energy-storage.news/wp-content/uploads/2022/09/Form-Energy-dotplot_year_duration.png Increase in curtailment in California, 2014—2022]
- [https://535485.smushcdn.com/698061/wp-content/uploads/2022/01/NEMlog-chart-2.jpg?lossy=1&strip=1&webp=1 Curtailment curves in South Australia], peaking at 69% (Christmas 2021)