The potential impact of climate change on European renewable energy droughts

Measuring the Dunkelflaute: How (not) to analyze variable renewable energy shortage

“…Comparability issues. Research interest is increasingly moving beyond single technologies at particular regions (e.g., [22-24, 27, 30]) towards a characterization of VRE drought patterns of portfolios of different renewable generation technologies for multiple regions (e.g., [18,19,33,34]). For this, enabling comparability across VRE technologies and regions when analyzing VRE drought events is imperative.…”

“…An effective option for this is to align the drought threshold with each system's mean availability factor φV RE . This method inherently scales with the system's FLH and, therefore, enables comparability across technologies or technology portfolios, regions, and, in the case of comparing multiple years, time [18,19,32,34,41].…”

“…One option is searching for 'drought windows' with predefined duration [18,19,34] 1 , e.g., a given number of time steps below a given threshold (Figure 2a). Implementing a respective search algorithm for a specified window duration is straightforward.…”

“…variable renewable energy shortage generic term including both approaches variable renewable energy droughts focusing on resource availability, considering VRE availability time series only extreme low wind generation events Cannon et al [22] low wind generation events Potisomporn & Vogel [23] low wind speed events Potisomporn et al [24] wind droughts Potisomporn et al [17] hydrologic droughts Yevyevich [25] streamflow droughts Fleig et al [26] extreme low wind events Abdelaziz et al [27] extended periods of low wind events Leahy & McKeogh [28] low wind speed events Patlakas et al [29] extreme low-wind-power events Ohlendorf & Schill [30] wind droughts Antonini et al [31] energy production droughts Raynaud et al [19] wind & solar resource droughts Rinaldi et al [18] wind & solar energy droughts Gangopadhyay et al [32] low generation events Kies et al [33] renewable energy droughts Kapica et al [34] renewable energy droughts Hu et al [35] dark lulls Breyer et al [36] low wind & solar production events Kaspar et al [37] Dunkelflauten Mockert et al [38] Dunkelflauten Mayer et al [39] dark doldrums Ohba et al [40] energy production droughts Otero et al [41] energy production droughts Allen & Otero [42] wind and solar (power) droughts Brown et al [16] wind and solar energy droughts Bracken et al [43] energy production droughts Bracken et al [43] low wind & solar production events van der Wiel et al [21] positive residual load events focusing on supply gaps, considering imbalances of electric load and VRE availability energy supply droughts Raynaud et al [19] gaps between VRE supply & demand Rinaldi et al [18] Dunkelflaute in high demand period Mayer et al [39] energy compound events Otero et al [44]…”

“…Using a composite VRE portfolio time series that combines wind and PV availability, they search for periods constantly below a range of exogenous thresholds. Kapica et al [34] compare energy droughts for solar PV and wind in Europe, either separately or as a combined portfolio, for historical and future weather conditions retrieved from eight regional climate models. Their identification method again draws on [19] with thresholds relative to seasonal and regional averages.…”