Solar Eclipse Causes Variable Energy Losses Across Europe and North America

The solar eclipse on August 12 created highly variable solar energy losses across Europe and North America, influenced by factors such as obscuration levels, cloud cover, and the timing of the event. Despite these differences, some locations in the U.S. and Europe saw comparable daily irradiance reductions, according to an analysis by Solcast, a DNV company. ## Irradiance Losses Defy Obscuration Expectations While the eclipse's path of totality crossed Greenland, Iceland, and Spain, much of Western Europe experienced over 80% obscuration, whereas the northeastern U.S. saw less than 20%. Despite these disparities, daily irradiance losses were similar in certain European and North American regions. For instance, Montreal, with less than 20% peak obscuration, recorded losses comparable to higher-obscuration European locations due to midday timing and cloud cover. In contrast, Iceland, which lay within the path of totality, saw minimal additional losses because cloud cover reduced the impact. Reykjavik, for example, would have lost over 5% of its daily solar resource under clear skies, but cloud cover limited the eclipse-related loss to below 1%. ## Market Impacts Vary by Region The eclipse’s effect on electricity markets was inconsistent, demonstrating that irradiance loss alone does not predict price changes. Spain, which experienced high obscuration, saw day-ahead prices rise to €175-250/MWh during the eclipse, about 10% higher than typical summer weekday levels but still below the highest prices of summer 2026. France, meanwhile, saw prices exceed the summer weekday median and interquartile range during the eclipse period, though the eclipse was not the sole factor. In contrast, New York’s Hudson Valley zone maintained prices within the usual summer weekday range, showing no significant deviation. ## Cloud Cover and Timing Influence Outcomes Cloud cover played a crucial role in mitigating losses in some regions. While western Europe had limited cloud cover during the eclipse, Iceland and parts of the UK and Ireland saw reduced impacts due to overcast conditions. The timing of the eclipse also mattered-North America experienced it near midday, when irradiance was high, while western Europe saw it just before sunset, when irradiance was already declining. Solcast’s analysis, which uses satellite data and AI-driven models, highlights that factors beyond obscuration-such as cloud cover and market conditions-significantly influence the solar energy and market impacts of eclipses. The findings underscore the complexity of predicting energy disruptions during such events.