▶ The combined use of short-duration flexibility options and LDS for coping with extreme #Dunkelflaute events decreases the need for electrolyzer and battery storage discharging capacity, which minimizes system costs.

▶ Geographical balancing helps mitigating #Dunkelflaute events, but significant LDS needs remain: Under policy-relevant interconnection assumptions, Europe would need 351 TWh (7% of annual demand) to cope with the worst event.

Key insights:
▶ #Dunkelflaute events drive LDS needs: Extreme events affecting multiple countries simultaneously - as occurred in the winter of 1996/97 (more info: lnkd.in/es6fwi7N) - define LDS sizing and operation.

🌬️☀️ How to deal with #Dunkelflaute events in Europe? Long-duration electricity storage (LDS) is key ⚡🔋

Check out our new pre-print “Coping with the Dunkelflaute: Power system implications of variable renewable energy droughts in Europe”: arxiv.org/abs/2411.17683

🧵A Thread 👇

17/ When detecting the mismatch of VRE availability with demand, no deliberate threshold is needed - it is simply zero (gray line). We again formalize, compare, and critically evaluate several algorithms that work analogously to those used in VRE drought identification.

9/ Choose your search algorithm wisely! Commonly used algorithms identify droughts with varying duration from the same data (cp. horizontal bars). We formalize, compare, and critically evaluate these methods, introducing a new algorithm that overcomes crucial shortcomings.

8/ Instead, search for drought events with variable duration, from hours to weeks or even months. Note the drought threshold’s impact: Higher thresholds identify less severe but longer-lasting events, reducing the number of obtained droughts by merging separate events into one.

7/ Droughts are defined as periods below a drought threshold. For accurate measurement, avoid fixed-duration “drought windows”, which may miss parts of the drought & lead to adjacent windows that should be combined, thus underestimating durations and overestimating occurrences.

4/ We propose terminology to harmonize the debate:
#VREDroughts for periods with low resource availability across one or multiple VRE technologies, #PositiveResidualLoadEvents for periods where VRE supply falls short of electric load.

2/ In our latest pre-print,@WPSchill
and I explore how (not) to analyze such shortage periods: doi.org/10.48550/arX...

Slide of the day: How is the power sector transition in OECD countries going? Simply put: it is still lagging behind. In August 2023, the renewable share reached just about 30%. Note: this is excl. China and India.

www.iea.org/data-and-sta...

Slide of the day from IEA World Energy Outlook 2023: Globally, the fossil industry is still reluctant to go for low/zero carbon technologies, while a massive redistribution of wealth from the general public as energy consumers to the fossil industry's shareholders has taken place.