# Dunkelflaute

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Dunkelflaute
> Markdown URL: https://mediated.wiki/source/Dunkelflaute.md
> Source: https://en.wikipedia.org/wiki/Dunkelflaute
> Source revision: 1321946044
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Long period of gloomy calm weather

A *dunkelflaute* of three days in Germany 2023 (wind in light blue and solar in yellow)

In the [renewable energy](/source/Renewable_energy) sector, a ***dunkelflaute*** (German: [\[ˈdʊŋkəlˌflaʊtə\]](https://en.wikipedia.org/wiki/Help:IPA/Standard_German) [ⓘ](https://en.wikipedia.org/wiki/File:De-Dunkelflaute.ogg), lit. 'dark doldrums' or 'dark wind lull', plural *dunkelflauten*)[1] is a period of time in which little or no energy can be generated with [wind](/source/Wind_power) and [solar power](/source/Solar_power), because there is neither wind nor sunlight.[2][3][4] In [meteorology](/source/Meteorology), this is known as **anticyclonic gloom**.[5]

## Meteorology

A cloudy and foggy January evening in Austria, one hour before sunset

Unlike a typical [anticyclone](/source/Anticyclone), *dunkelflauten* are associated not with clear skies, but with very dense [cloud cover](/source/Cloud_cover) (0.7–0.9), consisting of [stratus](/source/Stratus_cloud), [stratocumulus](/source/Stratocumulus_cloud), and fog.[6] As of 2022[\[update\]](https://en.wikipedia.org/w/index.php?title=Dunkelflaute&action=edit) there is no agreed quantitative definition of *dunkelflaute*.[7] Li et al. define it as wind and solar both below 20% of [capacity](/source/Capacity_factor) during a particular 60-minute period.[8] High [albedo](/source/Albedo) of low-level stratocumulus clouds in particular – sometimes the [cloud base](/source/Cloud_base) height is just 400 meters – can reduce [solar irradiation](/source/Solar_irradiation) by half.[6]

In the north of Europe, *dunkelflauten* originate from a static high-pressure system that causes an extremely weak wind combined with [overcast](/source/Overcast) weather with [stratus](/source/Stratus_cloud) or [stratocumulus](/source/Stratocumulus_cloud) clouds.[9] There are 2–10 *dunkelflaute* events per year.[10] Most of these events occur from October to February; typically 50 to 150 hours per year, a single event usually lasts up to 24 hours.[11][*[failed verification](https://en.wikipedia.org/wiki/Wikipedia:Verifiability)*]

In Japan, on the other hand, *dunkelflauten* are seen in summer and winter. The former is caused by stationary fronts in early summer and autumn rainy seasons (called Baiu and Akisame, respectively),[12] while the latter is caused by arrivals of south-coast cyclones.[13]

## Renewable energy effects

These periods are a big issue in energy infrastructure if a significant amount of electricity is generated by [variable renewable energy](/source/Variable_renewable_energy) (VRE) sources, mainly solar and wind power.[14][1][15] *Dunkelflauten* can occur simultaneously over a very large region, but are less correlated between geographically distant regions, so multi-national power grid schemes can be helpful.[16] Events that last more than two days over most of Europe happen about once every five years.[17] To ensure power during such periods flexible energy sources may be used, [energy may be imported](/source/Interconnector), and [demand may be adjusted](/source/Energy_demand_management).[18][19]

For alternative energy sources, countries use fossil fuels ([coal](/source/Coal), [oil](/source/Oil) and [natural gas](/source/Methane_gas)), [hydroelectricity](/source/Hydroelectricity) or [nuclear power](/source/Nuclear_power) and, less often, [energy storage](/source/Energy_storage) to prevent [power outages](/source/Power_outage).[20][21][8][22] Long-term solutions include designing [electricity markets](/source/Electricity_market) to incentivise clean power which is available when needed.[19] A group of countries is following on from [Mission Innovation](/source/Mission_Innovation) to work together to solve the problem in a clean, low-carbon way by 2030, including looking into [carbon capture and storage](/source/Carbon_capture_and_storage) and the [hydrogen economy](/source/Hydrogen_economy) as possible parts of the solution.[23]

### Droughts

By analogy with hydrological [droughts](/source/Drought), long used in planning for [hydroelectricity](/source/Hydroelectricity), the researchers of the future VRE-intensive power grids in the 2020s started using the term **variable renewable energy drought** (**VRE drought** or simply **power drought**) that is nearly synonymous to the dunkelflaute.[24][25] Unlike the dunkelflaute, the drought can be a series of isolated adverse events, the most severe effects are forecasted are of this series type, and the planning for [resource adequacy](/source/Resource_adequacy) thus should span multiple years.[26] Kittel et al. indicate the years 1996–1997 as particularly bad example of the VRE drought, they call for an additional EU-wide energy storage of 50 to 170 [TWh](/source/TWh) (on top of current projections) to accommodate a series of events of this magnitude.[27]

## See also

- [Duck curve](/source/Duck_curve)

- [Variable renewable energy](/source/Variable_renewable_energy)

## References

1. ^ [***a***](#cite_ref-gap_1-0) [***b***](#cite_ref-gap_1-1) ["When the wind goes, gas fills in the gap | Q1 2021 Quarterly Report"](https://reports.electricinsights.co.uk/q1-2021/when-the-wind-goes-gas-fills-in-the-gap/). *Electric Insights*. 24 May 2021. Retrieved 29 June 2021.

1. **[^](#cite_ref-2)** ["Dark doldrums: When wind and sun take a break"](https://www.en-former.com/en/dark-doldrums-when-wind-and-sun-take-a-break/). *en-former.com*. 31 July 2018. Retrieved 27 May 2021.

1. **[^](#cite_ref-3)** Matsuo, Yuhji; Endo, Seiya; Nagatomi, Yu; Shibata, Yoshiaki; Komiyama, Ryoichi; Fujii, Yasumasa (1 June 2020). ["Investigating the economics of the power sector under high penetration of variable renewable energies"](https://www.sciencedirect.com/science/article/abs/pii/S0306261919316435). *Applied Energy*. **267** 113956. [Bibcode](/source/Bibcode_(identifier)):[2020ApEn..26713956M](https://ui.adsabs.harvard.edu/abs/2020ApEn..26713956M). [doi](/source/Doi_(identifier)):[10.1016/j.apenergy.2019.113956](https://doi.org/10.1016%2Fj.apenergy.2019.113956). [ISSN](/source/ISSN_(identifier)) [0306-2619](https://search.worldcat.org/issn/0306-2619). [S2CID](/source/S2CID_(identifier)) [216301290](https://api.semanticscholar.org/CorpusID:216301290).

1. **[^](#cite_ref-4)** Ohba, Masamichi; Kanno, Yuki; Nohara, Daisuke (8 December 2021). ["Climatology of dark doldrums in Japan"](https://www.sciencedirect.com/science/article/pii/S1364032121011928). *Renewable and Sustainable Energy Reviews*. **155** 111927. [doi](/source/Doi_(identifier)):[10.1016/j.rser.2021.111927](https://doi.org/10.1016%2Fj.rser.2021.111927). [S2CID](/source/S2CID_(identifier)) [245067748](https://api.semanticscholar.org/CorpusID:245067748).

1. **[^](#cite_ref-FOOTNOTELiBasuWatsonRusschenberg20212_5-0)** [Li et al. 2021](#CITEREFLiBasuWatsonRusschenberg2021), p. 2.

1. ^ [***a***](#cite_ref-FOOTNOTELiBasuWatsonRusschenberg20217_6-0) [***b***](#cite_ref-FOOTNOTELiBasuWatsonRusschenberg20217_6-1) [Li et al. 2021](#CITEREFLiBasuWatsonRusschenberg2021), p. 7.

1. **[^](#cite_ref-7)** ["Was ist die Dunkelflaute? | Definition"](https://www.next-kraftwerke.de/wissen/dunkelflaute) [What are the Dark Doldrums?]. *next-kraftwerke.de* (in German). Retrieved 13 December 2022.

1. ^ [***a***](#cite_ref-LiBasu2020_8-0) [***b***](#cite_ref-LiBasu2020_8-1) Li, Bowen; Basu, Sukanta; Watson, Simon J.; Russchenberg, Herman W. J. (2020). ["Mesoscale modeling of a "Dunkelflaute" event"](https://doi.org/10.1002%2Fwe.2554). *Wind Energy*. **24** (1): 5–23. [doi](/source/Doi_(identifier)):[10.1002/we.2554](https://doi.org/10.1002%2Fwe.2554). [ISSN](/source/ISSN_(identifier)) [1095-4244](https://search.worldcat.org/issn/1095-4244).

1. **[^](#cite_ref-FOOTNOTELiBasuWatsonRusschenberg20216_9-0)** [Li et al. 2021](#CITEREFLiBasuWatsonRusschenberg2021), p. 6.

1. **[^](#cite_ref-FOOTNOTELiBasuWatsonRusschenberg202111_10-0)** [Li et al. 2021](#CITEREFLiBasuWatsonRusschenberg2021), p. 11.

1. **[^](#cite_ref-FOOTNOTELiBasuWatsonRusschenberg20211_11-0)** [Li et al. 2021](#CITEREFLiBasuWatsonRusschenberg2021), p. 1.

1. **[^](#cite_ref-12)** Ohba, Masamichi; Kanno, Yuki; Nohara, Daisuke (8 December 2021). ["Climatology of dark doldrums in Japan"](https://www.sciencedirect.com/science/article/pii/S1364032121011928). *Renewable and Sustainable Energy Reviews*. **155** 111927. [doi](/source/Doi_(identifier)):[10.1016/j.rser.2021.111927](https://doi.org/10.1016%2Fj.rser.2021.111927). [S2CID](/source/S2CID_(identifier)) [245067748](https://api.semanticscholar.org/CorpusID:245067748).

1. **[^](#cite_ref-13)** Ohba, Masamichi; Kanno, Yuki; Shigeru, Bando (21 January 2023). ["Effects of meteorological and climatological factors on extremely high residual load and possible future changes"](https://www.sciencedirect.com/science/article/pii/S1364032123000448). *Renewable and Sustainable Energy Reviews*. **175** 113188. [Bibcode](/source/Bibcode_(identifier)):[2023RSERv.17513188O](https://ui.adsabs.harvard.edu/abs/2023RSERv.17513188O). [doi](/source/Doi_(identifier)):[10.1016/j.rser.2023.113188](https://doi.org/10.1016%2Fj.rser.2023.113188).

1. **[^](#cite_ref-14)** Walker, Tamsin (8 February 2017). ["What happens with German renewables in the dead of winter?"](https://www.dw.com/en/what-happens-with-german-renewables-in-the-dead-of-winter/a-37462540). *[Deutsche Welle](/source/Deutsche_Welle)*. [Archived](https://web.archive.org/web/20170209102347/https://www.dw.com/en/what-happens-with-german-renewables-in-the-dead-of-winter/a-37462540) from the original on 9 February 2017. Retrieved 28 May 2021.

1. **[^](#cite_ref-15)** Ohba, Masamichi; Kanno, Yuki; Shigeru, Bando (21 January 2023). ["Effects of meteorological and climatological factors on extremely high residual load and possible future changes"](https://www.sciencedirect.com/science/article/pii/S1364032123000448). *Renewable and Sustainable Energy Reviews*. **175** 113188. [Bibcode](/source/Bibcode_(identifier)):[2023RSERv.17513188O](https://ui.adsabs.harvard.edu/abs/2023RSERv.17513188O). [doi](/source/Doi_(identifier)):[10.1016/j.rser.2023.113188](https://doi.org/10.1016%2Fj.rser.2023.113188).

1. **[^](#cite_ref-FOOTNOTELiBasuWatsonRusschenberg20219_16-0)** [Li et al. 2021](#CITEREFLiBasuWatsonRusschenberg2021), p. 9.

1. **[^](#cite_ref-17)** McDonnell, Tim (13 December 2022). ["Can Europe survive the dreaded dunkelflaute?"](https://qz.com/can-europe-survive-the-dreaded-dunkelflaute-1849886529). *Quartz*. Retrieved 1 February 2023.

1. **[^](#cite_ref-18)** [Modelling 2050: Electricity System Analysis](https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/943714/Modelling-2050-Electricity-System-Analysis.pdf) (PDF) (Report). [Department for Business, Energy and Industrial Strategy](/source/Department_for_Business%2C_Energy_and_Industrial_Strategy). December 2020. Retrieved 12 December 2023.

1. ^ [***a***](#cite_ref-push_19-0) [***b***](#cite_ref-push_19-1) ["The dreaded Dunkelflaute is no reason to slow UK's energy push"](https://www.ft.com/content/93d61f33-b1f9-4791-a9f8-37d826bd68af). *Financial Times*. 13 December 2022. Retrieved 13 December 2022.

1. **[^](#cite_ref-KosowskiDiercks2021_20-0)** Kosowski, Kai; Diercks, Frank (2021). ["Quo Vadis, Grid Stability?"](https://kernd.de/wp-content/uploads/2023/08/Article-atw-2021-2-Quo-vadis-Grid-Stability-Kosowski-Diercks.pdf) (PDF). *Atw*. **66** (2): 16–26. [ISSN](/source/ISSN_(identifier)) [1431-5254](https://search.worldcat.org/issn/1431-5254).

1. **[^](#cite_ref-21)** Ernst, Damien. ["Big infrastructures for fighting climate change"](https://orbi.uliege.be/bitstream/2268/243620/1/Ernst-EIB.pdf) (PDF). *Université de Liège*.

1. **[^](#cite_ref-AbbottCohen2020_22-0)** Abbott, Malcolm; Cohen, Bruce (2020). "Issues associated with the possible contribution of battery energy storage in ensuring a stable electricity system". *The Electricity Journal*. **33** (6) 106771. [Bibcode](/source/Bibcode_(identifier)):[2020ElecJ..3306771A](https://ui.adsabs.harvard.edu/abs/2020ElecJ..3306771A). [doi](/source/Doi_(identifier)):[10.1016/j.tej.2020.106771](https://doi.org/10.1016%2Fj.tej.2020.106771). [ISSN](/source/ISSN_(identifier)) [1040-6190](https://search.worldcat.org/issn/1040-6190). [S2CID](/source/S2CID_(identifier)) [218966955](https://api.semanticscholar.org/CorpusID:218966955).

1. **[^](#cite_ref-23)** Harrabin, Roger (2 June 2021). ["Major project aims to clear clean energy hurdle"](https://www.bbc.com/news/science-environment-57313991). *BBC News*. Retrieved 3 June 2021.

1. **[^](#cite_ref-FOOTNOTEKittelRothSchill20241,_5_24-0)** [Kittel, Roth & Schill 2024](#CITEREFKittelRothSchill2024), pp. 1, 5.

1. **[^](#cite_ref-FOOTNOTESahooTimmann202349691_25-0)** [Sahoo & Timmann 2023](#CITEREFSahooTimmann2023), p. 49691.

1. **[^](#cite_ref-FOOTNOTEKittelRothSchill202414_26-0)** [Kittel, Roth & Schill 2024](#CITEREFKittelRothSchill2024), p. 14.

1. **[^](#cite_ref-FOOTNOTEKittelRothSchill20249,_14_27-0)** [Kittel, Roth & Schill 2024](#CITEREFKittelRothSchill2024), pp. 9, 14.

## Sources

- Kittel, Martin; Roth, Alexander; Schill, Wolf-Peter (2024). ["Variable renewable energy droughts ("Dunkelflauten") and power sector implications"](https://www.diw.de/documents/vortragsdokumente/220/diw_01.c.901323.de/v_2024_kittel_dunkelflauten_enerday.pdf) (PDF). [DIW Berlin](/source/DIW_Berlin). Retrieved 14 December 2024.

- Kittel, Martin; Schill, Wolf-Peter (2024). "Measuring the Dunkelflaute: How (Not) to analyze variable renewable energy shortage". *Environmental Research: Energy*. **1** (3): 035007. [arXiv](/source/ArXiv_(identifier)):[2402.06758](https://arxiv.org/abs/2402.06758). [Bibcode](/source/Bibcode_(identifier)):[2024EREne...135007K](https://ui.adsabs.harvard.edu/abs/2024EREne...135007K). [doi](/source/Doi_(identifier)):[10.1088/2753-3751/ad6dfc](https://doi.org/10.1088%2F2753-3751%2Fad6dfc).

- Li, Bowen; Basu, Sukanta; Watson, Simon J.; Russchenberg, Herman W. J. (11 October 2021). ["A Brief Climatology of Dunkelflaute Events over and Surrounding the North and Baltic Sea Areas"](https://pure.tudelft.nl/ws/portalfiles/portal/100313934/energies_14_06508.pdf) (PDF). *Energies*. **14** (20): 6508. [doi](/source/Doi_(identifier)):[10.3390/en14206508](https://doi.org/10.3390%2Fen14206508). [eISSN](/source/EISSN_(identifier)) [1996-1073](https://search.worldcat.org/issn/1996-1073).

- Sahoo, Subrat; Timmann, Pascal (2023). ["Energy Storage Technologies for Modern Power Systems: A Detailed Analysis of Functionalities, Potentials, and Impacts"](https://ieeexplore.ieee.org/ielx7/6287639/10005208/10121760.pdf) (PDF). *IEEE Access*. **11**: 49689–49729. [Bibcode](/source/Bibcode_(identifier)):[2023IEEEA..1149689S](https://ui.adsabs.harvard.edu/abs/2023IEEEA..1149689S). [doi](/source/Doi_(identifier)):[10.1109/ACCESS.2023.3274504](https://doi.org/10.1109%2FACCESS.2023.3274504). [ISSN](/source/ISSN_(identifier)) [2169-3536](https://search.worldcat.org/issn/2169-3536). Retrieved 14 December 2024.

- Somani, Abhishek; Barrett, Emily; Zhou, Zhi; Chan, Gavin; Middleton, Luke; Tarel, Guillaume; Campbell, Allison; Botterud, Audun; Bhatnagar, Dhruv; Beckitt, Alex; O'Reilley, Christopher; Zhu, Yanyan; Sun, Xueqing (1 May 2024). An Assessment of Resource Drought Events as Indicators for Long-Duration Energy Storage Needs (Report). [doi](/source/Doi_(identifier)):[10.2172/2349123](https://doi.org/10.2172%2F2349123). [OSTI](/source/OSTI_(identifier)) [2349123](https://www.osti.gov/biblio/2349123).

---
Adapted from the Wikipedia article [Dunkelflaute](https://en.wikipedia.org/wiki/Dunkelflaute) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Dunkelflaute?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.