{"id":372832,"date":"2025-03-30T16:42:58","date_gmt":"2025-03-30T14:42:58","guid":{"rendered":"https:\/\/climatescience.press\/?p=372832"},"modified":"2025-03-30T16:43:01","modified_gmt":"2025-03-30T14:43:01","slug":"more-on-german-dunkelflautes","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=372832","title":{"rendered":"More on German\u00a0Dunkelflautes"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

From Trust, yet verify<\/a><\/p>\n\n\n\n

In previous post, I was looking for two Dunkelflautes (periods of low wind and not much sunshine) in the German grid data. I looked specifically into the first half of November 2024 and around half December 2024, this because it was reported that Dunkelflautes occurred in those two periods.<\/p>\n\n\n\n

A commonly used definition of a Dunkelflaute is a period with a daily production of less than 10% of installed capacity. Unfortunately, I didn\u2019t have the exact capacity information for November and December 2024. A LinkedIn post that analyzed Dunkelflautes in Germany used the installed capacity of the beginning of the year and found 12 consecutive days in November and 3 consecutive days in December. I redid that analysis but with the installed capacity at the end of 2024 (which should be more appropriate for the end of the year) and found 14 consecutive days in November and 4 consecutive days in December.<\/p>\n\n\n\n

The actual number of Dunkelflaute days will depend on how much capacity was available at the end of 2024. When all the new capacity came available in the second half of December, then that would be 12 days in November and 3 days in December, as found in the LinkedIn post. When that capacity was already available at the beginning of November, then that would be 14 days in November and 4 in December. When some of that capacity was coming available in November or December, then that would be something in between, depending on how much capacity still had to come available at the end of the year.<\/p>\n\n\n\n

I limited myself in previous post to just those two date ranges, but the winter period in general is known for having Dunkelflaute events, so that made me wonder how frequent these occur. So, let\u2019s just extend the same analysis from November 2024 until now.<\/p>\n\n\n\n

The Agora data from 1 November 2024 until 28 March 2025<\/a> (when I finalize this post) gives this:<\/p>\n\n\n

\n
\"\"
(click the image to enlarge to see it more clear and with some extra details)<\/figcaption><\/figure>\n<\/div>\n\n\n

I used the installed capacity at the end of 2024 for the entire period (November 2024 \u2192 March 2025) in my calculation. Also here, the actual number of Dunkelfaute days in the first three months of 2025 will depend on how much capacity came available. When there was already new capacity available in that period, then there might be more days having less production than the 10% threshold than what I calculated.<\/p>\n\n\n\n

The longest Dunkelflaute is still the one of the first half of November 2024. There were however more periods than I expected. I count 14 periods with a production of less than 10% of installed capacity, of which 5 are single day and 9 spanned consecutive days:<\/p>\n\n\n\n

 <\/td>Start date<\/td>End date<\/td>Duration
(days)<\/td><\/tr>
1<\/td>02 Nov 2024<\/td>15 Nov 2024<\/td>14<\/td><\/tr>
2<\/td>29 Nov 2024<\/td>29 Nov 2024<\/td>1<\/td><\/tr>
3<\/td>04 Dec 2024<\/td>04 Dec 2024<\/td>1<\/td><\/tr>
4<\/td>10 Dec 2024<\/td>13 Dec 2024<\/td>4<\/td><\/tr>
5<\/td>24 Dec 2024<\/td>29 Dec 2024<\/td>6<\/td><\/tr>
6<\/td>04 Jan 2025<\/td>04 Jan 2025<\/td>1<\/td><\/tr>
7<\/td>12 Jan 2025<\/td>13 Jan 2025<\/td>2<\/td><\/tr>
8<\/td>15 Jan 2025<\/td>22 Jan 2025<\/td>8<\/td><\/tr>
9<\/td>01 Feb 2025<\/td>06 Feb 2025<\/td>6<\/td><\/tr>
10<\/td>13 Feb 2025<\/td>17 Feb 2025<\/td>5<\/td><\/tr>
11<\/td>25 Feb 2025<\/td>01 Mar 2025<\/td>5<\/td><\/tr>
12<\/td>10 Mar 2025<\/td>14 Mar 2025<\/td>5<\/td><\/tr>
13<\/td>24 Mar 2025<\/td>24 Mar 2025<\/td>1<\/td><\/tr>
14<\/td>26 Mar 2025<\/td>26 Mar 2025<\/td>1<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

I expected some periods of Dunkelflaute, but not that many! From the 148 days between 1 November 2024 and 28 March 2025, there were 60 days with a daily production of less than 10% of the installed capacity. That is 40% of the days in the period. That is much more than I expected. The average capacity factor was only 11.8% over the entire period. This in a period of the year when demand is at its highest.<\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

A commonly used definition of a Dunkelflaute is a period with a daily production of less than 10% of installed capacity. <\/p>\n","protected":false},"author":121246920,"featured_media":372839,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_crdt_document":"","advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[691834166,691819405,691818051,691834165],"class_list":{"0":"post-372832","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","8":"tag-agora-energiewende-2","9":"tag-dunkelflaute-or-dark-doldrums","10":"tag-germany","11":"tag-grid-data","13":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/03\/0RWE_Blog_Thema-Dunkelflaute_1340x590.webp?fit=1340%2C590&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-1yZq","jetpack-related-posts":[{"id":368211,"url":"https:\/\/climatescience.press\/?p=368211","url_meta":{"origin":372832,"position":0},"title":"The German Dunkelflautes at the end of\u00a02024","author":"uwe.roland.gross","date":"01\/03\/2025","format":false,"excerpt":"The German Weather Service (Deutscher Wetterdienst) mentioned a\u00a0Dunkelflaute between November 2 and 7\u00a0(meaning 6 days), but I found other (less reliable) sources that also included November 8 (so 7 days). The Dunkelflaute in December was even more elusive. I only found one (not reliable) source that mentioned December 10 \u2192\u2026","rel":"","context":"In \"Agorameter Energiewende\"","block_context":{"text":"Agorameter Energiewende","link":"https:\/\/climatescience.press\/?tag=agorameter-energiewende"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/03\/00energiewende-desaster-dunkelflaute-treibt-deutschland-in-die-stromkrise-1187.png?fit=1200%2C686&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/03\/00energiewende-desaster-dunkelflaute-treibt-deutschland-in-die-stromkrise-1187.png?fit=1200%2C686&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/03\/00energiewende-desaster-dunkelflaute-treibt-deutschland-in-die-stromkrise-1187.png?fit=1200%2C686&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/03\/00energiewende-desaster-dunkelflaute-treibt-deutschland-in-die-stromkrise-1187.png?fit=1200%2C686&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/03\/00energiewende-desaster-dunkelflaute-treibt-deutschland-in-die-stromkrise-1187.png?fit=1200%2C686&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":377048,"url":"https:\/\/climatescience.press\/?p=377048","url_meta":{"origin":372832,"position":1},"title":"Dunkelflautes: Germany versus\u00a0Belgium","author":"uwe.roland.gross","date":"02\/05\/2025","format":false,"excerpt":"Dunkelflaute = period in which total daily production of solar, and wind is less than 10% of its installed capacity","rel":"","context":"In \"Belgium\"","block_context":{"text":"Belgium","link":"https:\/\/climatescience.press\/?tag=belgium"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/077353323-07cf-485c-95eb-21caaaf9d66d_1280x720.jpg?fit=1200%2C600&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/077353323-07cf-485c-95eb-21caaaf9d66d_1280x720.jpg?fit=1200%2C600&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/077353323-07cf-485c-95eb-21caaaf9d66d_1280x720.jpg?fit=1200%2C600&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/077353323-07cf-485c-95eb-21caaaf9d66d_1280x720.jpg?fit=1200%2C600&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/077353323-07cf-485c-95eb-21caaaf9d66d_1280x720.jpg?fit=1200%2C600&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":359985,"url":"https:\/\/climatescience.press\/?p=359985","url_meta":{"origin":372832,"position":2},"title":"Do conventional and intermittent system have the same\u00a0dynamic?","author":"uwe.roland.gross","date":"01\/01\/2025","format":false,"excerpt":"Recently, I came across the blog post titled\u00a0The Dunkelflaute Disaster: What Happens When Wind Power Goes Silent. That post discusses the phenomenon known as Dunkelflaute, a German term that means \u201cdark doldrums\u201d (periods when there is little to no wind and sunlight, leading to a significant drop in energy production\u2026","rel":"","context":"In \"Dunkelflaute or \u2018dark doldrums\u2019\"","block_context":{"text":"Dunkelflaute or \u2018dark doldrums\u2019","link":"https:\/\/climatescience.press\/?tag=dunkelflaute-or-dark-doldrums"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/01\/0RWE_Blog_Thema-Dunkelflaute_1340x590.webp?fit=1200%2C528&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/01\/0RWE_Blog_Thema-Dunkelflaute_1340x590.webp?fit=1200%2C528&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/01\/0RWE_Blog_Thema-Dunkelflaute_1340x590.webp?fit=1200%2C528&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/01\/0RWE_Blog_Thema-Dunkelflaute_1340x590.webp?fit=1200%2C528&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/01\/0RWE_Blog_Thema-Dunkelflaute_1340x590.webp?fit=1200%2C528&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":233971,"url":"https:\/\/climatescience.press\/?p=233971","url_meta":{"origin":372832,"position":3},"title":"Belgium: Dunkelflautes last just a few hours (oops, days)","author":"uwe.roland.gross","date":"14\/12\/2022","format":false,"excerpt":"There was a dunkelflaute at the end of last month. \u201cDunkelflaute\u201d is a German word, mostly translated as \u201cdark doldrum\u201d.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/1resources-accelerate-1.jpg?fit=1200%2C730&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/1resources-accelerate-1.jpg?fit=1200%2C730&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/1resources-accelerate-1.jpg?fit=1200%2C730&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/1resources-accelerate-1.jpg?fit=1200%2C730&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/1resources-accelerate-1.jpg?fit=1200%2C730&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":350489,"url":"https:\/\/climatescience.press\/?p=350489","url_meta":{"origin":372832,"position":4},"title":"The Dunkelflaute Disaster: What Happens When Wind Power Goes Silent","author":"uwe.roland.gross","date":"07\/11\/2024","format":false,"excerpt":"In the latest illustration of why you can\u2019t rely on wishful thinking as a power source, the UK and Germany faced a harsh lesson in \u201cDunkelflaute.\u201d For those not familiar with this charming German term, it means \u201cdark doldrums\u201d\u2014or, in practical terms, a blackout in renewable power. 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