Investigating the Effects of Pacific Sea Surface Temperatures on the Wind Drought of 2015 Over the United States

Abstract

During the first quarter of 2015 the United States experienced a widespread and extended episode of low surface wind speeds. This episode had a strong impact on wind power generation. Some wind farms did not generate enough cash for their steady payments, and the value of some assets decreased. Although the wind industry expressed their concerns, the episode has not received much attention from the scientific community and remains weakly understood. In this paper we aim to fill this gap and advance understanding of the underlying processes at seasonal time scales. Using retrospective climate predictions, we find that high sea surface temperatures in the western tropical Pacific ocean associated with a strongly positive phase of the North Pacific Mode played a central role to establish and maintain those wind anomalies. In a more general way it has also been shown that interannual variability of wind speed over North America is not only dominated by El Niño/Southern Oscillation but also by other sea surface temperature variations in the tropical Pacific. This new knowledge can be useful for industry stakeholders to anticipate future periods of low wind speed.

What global reanalysis best represents near‐surface winds?

“…In recent years, the climate prediction community has started to unveil the climate drivers of anomalous events such as wind droughts (e.g., Lledó et al . ) and to produce seasonal forecasts (Doblas‐Reyes et al . ; Clark et al .…”

“…Another frequent usage of reanalyses for already operating wind farms is to understand the causes of anomalous wind speed episodes that impacted generation and revenues on monthly or seasonal time-scales. In recent years, the climate prediction community has started to unveil the climate drivers of anomalous events such as wind droughts (e.g., Lledó et al, 2018) and to produce seasonal forecasts (Doblas-Reyes et al, 2013;Clark et al, 2017) to anticipate those wind speed anomalies that can have an impact on wind energy activity. In this climate prediction framework, reanalyses are also used as observational reference for the adjustment of systematic errors affecting these predictions (Torralba et al, 2017b) and to assess the forecast quality (Jolliffe and Stephenson, 2012).…”

Better seasonal forecasts for the renewable energy industry

“…For instance, the USA experienced low surface wind speeds and thereby a reduction in wind power among some wind farms during the first quarter of 2015. This wind drought in the USA was to a large extent caused by high sea surface temperatures in the tropical Pacific 7 . Variability in temperatures and precipitation can also affect runoff and thereby hydropower generation 8 , as can the occurrence of climate extremes such as droughts and floods 9 .…”

High Resolution Wind Power and Wind Drought Models

“…A further challenge from wind variability risk arises during calm periods. The first quarter of 2015 saw surface wind speeds well below normal in most of the contiguous United States [15]. This reduced the electricity generation of most of the wind farms in the country, but particularly Texas, Oklahoma, and Kansas, where most of the biggest wind farms are concentrated.…”