Frequency and duration of low-wind-power events in Germany

Nils Ohlendorf,Wolf-Peter Schill

doi:10.1088/1748-9326/ab91e9

Abstract

In the transition to a renewable energy system, the occurrence of low-wind-power events receives increasing attention. We analyze the frequency and duration of such events for onshore wind power in Germany, based on 40 years of reanalysis data and open software. We find that low-wind-power events are less frequent in winter than in summer, but the maximum duration is distributed more evenly between months. While short events are frequent, very long events are much rarer. Every year, a period of around five consecutive days with an average wind capacity factor below 10% occurs, and every ten years a respective period of nearly eight days. These durations decrease if only winter months are considered. The longest event in the data lasts nearly ten days. We conclude that public concerns about low-wind-power events in winter may be overrated, but recommend that modeling studies consider multiple weather years to properly account for such events.

Highlights

The Paris Agreement calls for an extensive decarbonization of the global economy
Parts of our analysis explicitly focus on winter months: these are relevant, as power generation from solar PV is relatively low during this season, while the German peak load occurs in winter
Seasonal distribution and frequency of low-wind-power events Figure 6 shows that LWP events are generally most frequent in summer and least frequent in winter (December-February)

Summary

Introduction

The Paris Agreement calls for an extensive decarbonization of the global economy. A major strategy for achieving this goal is a massive expansion of variable renewable energy sources, in particular solar photovoltaics (PV) and wind power (de Coninck et al 2018). In countries with growing shares of wind power, the occurrence of low-wind-power (LWP) events receives increasing attention. Concerns about LWP events have been discussed in German media (Wetzel 2017, Wetzel 2019) and in the German parliament (Deutscher Bundestag 2019a), and LWP events are mentioned in the government’s energy transition reporting (Deutscher Bundestag 2019b). In this context, the term Dunkelflaute is increasingly used. In table 15 of (Deutscher Bundestag 2019b), an independent expert commission generally assumes a nowind-no-solar period of two weeks

Methods

Results

Conclusion