Study disproves idea that weather-dependent renewable energy systems are more prone to blackouts

Wind turbines and photovoltaics (PVs) are becoming increasingly widespread worldwide, which could contribute to reducing air pollution caused by fossil fuel emissions. To produce energy, however, these renewable energy solutions rely on specific weather conditions (e.g., the presence of wind and sufficient hours of sunlight).

A report by the US Energy Information Administration (EIA) predicted that by 2050, approximately 44% of electricity in the US will be generated by solar and wind technologies. As the use of these technologies grows, some energy system operators have expressed concerns about the weather-dependency of these systems, suggesting that an overreliance on these technologies could increase the risk of blackouts.

In some instances, renewable energy systems were even blamed for blackouts experienced during adverse weather events. For example, blackouts experienced in February 2021 throughout Texas were initially and mistakenly believed to be caused by the failure of wind and solar technologies to generate energy in the cold winter weather.

Researchers at the University of Tennessee recently carried out a study exploring the vulnerability of renewable energy systems to adverse weather and the extent to which these systems could be responsible for severe blackouts. Their findings, published in Nature Energy, suggest that solar panels and wind turbines are less likely to cause severe blackouts than traditional power systems.

“The high penetration of weather-dependent renewable energy sources (WD-RESs) such as wind and solar has raised concerns about the security of electric power systems during abnormal weather conditions,” Jin Zhao, Fangxing Li and Qiwei Zhang wrote in their paper.

“The role of RESs has been discussed in worldwide blackout events, yet remains controversial. In this study, we find that although WD-RESs are non-dispatchable and weather sensitive, blackout intensities and extreme weather vulnerability are mitigated in high-penetration WD-RES grids.”

As part of their study, the researchers filtered data collected during 2,156 real-world bulk system blackout events, along with weather data recorded in 278 cities spread across 48 states in the US over a 20-year period (from 2001 to 2020). They organized this data by filtering out the weather in affected regions when the blackouts took place, as well as data relevant to the deployment of wind and solar energy systems in these regions.

Subsequently, Zhao, Li and Zhang analyzed the organized dataset using statistical techniques and an unsupervised deep learning model. Their findings show that systems relying on WD-RES are not actually more vulnerable to causing blackouts during unfavorable weather events.

“The causal effects of WD-RESs on blackouts generally decrease in high-penetration WD-RES power systems, and WD-RESs are not mainly responsible for the occurrence of blackouts in extreme weather conditions,” wrote Zhao, Li and Zhang.

“The results of our research contribute to the debate on RES integration and power system security, offer a guide for the study of power system resilience and provide a reference for the ambitious high-penetration RES goals of the future.”

Overall, the results of this recent study suggest that weather-dependent renewable energy systems, particularly solar panels and wind turbines, are not as prone to causing severe bulk power system blackouts during extreme weather as some people have assumed them to be. In fact, blackouts that occurred in regions with a high penetration of WD-RES power grids were often less severe than those occurring in places that only relied on the traditional power grid.

While these findings are promising, further studies with larger and more comprehensive datasets are needed to confirm their generalizability. For instance, the team only analyzed data collected in the US. Thus, future research could perform similar analyses using data collected in other countries worldwide.

© 2024 Science X Network