New research into the vulnerability of power grids, particularly those heavily reliant on weather-dependent renewable energy sources (WD-RESs) like wind and solar, presents promising findings for Ireland’s energy future. Published in the prestigious journal Nature Energy, the study, which analysed US blackout data from 2001 to 2020, reveals that power grids with a high penetration of WD-RESs tend to experience blackouts of lower intensity. These results are particularly significant for Ireland, as the country works towards meeting its ambitious climate emissions reduction targets by increasing its reliance on renewable energy.

In 2023, renewable energy accounted for 38.9% of Ireland’s electricity generation, and this share is expected to rise to over 70% by 2030. The transition towards a grid primarily powered by weather-dependent renewables is crucial for meeting Ireland’s climate goals, but concerns about the reliability of such grids have been raised. Many fear that the intermittency and unpredictability of wind and solar power could lead to more frequent and severe blackouts, especially during extreme weather events.

However, the findings of this study paint a hopeful picture for Ireland’s renewable energy future. Jin Zhao, Assistant Professor at Trinity College Dublin’s School of Engineering, who led the research, explained: “Some have claimed that unstable RESs are responsible for increasing power grid unreliability under extreme climate conditions, whereas others have argued that wind and solar generation tend to be available even during extreme weather.”

Zhao’s research sought to bridge the gap in understanding regarding the role of WD-RESs in power grid blackouts. “The lack of understanding of the impacts of WD-RESs on power system blackouts has raised doubts about their use and, in some cases, driven a backlash against wind and solar integration. Considering the ambitious high-RES penetration and carbon emission goals that have been set for future power systems, it was high time we improved our understanding of the role RESs play in blackouts,” he said.

Key Findings: WD-RESs Don’t Increase Blackout Vulnerability

The study found that power systems with higher WD-RES penetration did not experience greater vulnerability to blackouts. In fact, when blackouts did occur, they were less intense in grids with higher renewable penetration. This reduction in blackout intensity was indicated by a lower number of customers affected, less demand loss, and shorter blackout durations. The research also concluded that although extreme weather conditions did increase a power system's vulnerability to blackouts, high WD-RES penetration did not exacerbate this vulnerability, even in cases where the blackouts were caused by weather events.

Prof. Zhao elaborated: “The major take-home message here is that WD-RESs are not the main culprit for blackouts during extreme weather events. In fact, higher-penetration grids tend to experience lower blackout intensities when they do occur.”

The findings are particularly encouraging for Ireland, where the power grid is in the midst of a transition to more renewable energy sources. Ireland’s relatively small, lower-inertia power grid may be more sensitive to fluctuations than the larger, interconnected systems in the US or continental Europe. As Zhao noted, this means it’s crucial for Ireland to conduct similar research tailored to its specific energy system. “All of this makes it super important to specifically focus on our Irish power system with similar research, and that is the next step for us – we have recently secured funding to do just that.”

With renewable energy set to play an increasingly central role in Ireland’s future power grid, these findings offer reassurance that the country’s renewable transition will not only help reduce carbon emissions but could also improve grid resilience. The next steps in the research will focus on further examining the potential benefits of high-RES penetration for Ireland’s energy system, providing vital insights as the nation works towards its renewable energy goals.

The full study is available on the Nature Energy website.