This year’s rare “super El Niño” could be the world’s next energy market shock, analysts say, threatening renewable energy production in some places as it drives extreme heat.
The climate phenomenon arrives as the monthslong Iran war strains global oil markets — and prompts some world leaders, particularly in Europe and China, to consider an expansion of their renewable portfolios. Studies show that solar, wind and hydropower tend to take a hit in certain regions during El Niño years, as cloud cover, wind patterns and rainfall change.
“We do have predictions,” said Roberta Boscolo, climate and energy lead at the World Meteorological Organization. “The predictions are rather solid.”
The data comes from an annual report published by WMO, in partnership with the International Renewable Energy Agency. The first two reports analyzed trends in 2023 and 2024, when a strong El Niño event was in force for at least half of both years.
While solar, wind and hydropower capacity increased globally during those years, it decreased in some regions. In some areas of South America and southern Africa, for example, El Niño’s influence caused hydropower to decline, according to the reports. Those regions are also likely to experience extreme El Niño-driven heat — which can boost solar generation but also drive electricity demand skyward and further strain the grid.
It remains to be seen what’s in store as the latest El Niño gets underway. But predictions from previous years “are a very powerful tool for countries to be ready to prepare and to minimize the impacts on renewable energy generation for their national supply,” Boscolo said.
Here is how this year’s strong El Niño could impact renewable energy.
Solar
Aside from the WMO’s reports, relatively few studies have examined the global effects of El Niño on renewable energy. But one recent paper, published in March in the scientific journal Communications Earth & Environment, took a look for the first time at the climate cycle’s global impacts on solar power.
The researchers found that El Niño reduces the sun’s radiation — and causes solar energy deficits — in regions with growing solar energy capacity. That includes parts of the Western U.S., particularly California, as well as parts of South America, the Middle East and eastern China.
The study also found that the effects are strongest during “super El Niño” events, which cause temperatures in the central and eastern Pacific Ocean to rise more than 2 degrees Celsius above their average levels. Based on previous strong events, researchers estimated that the next super El Niño could reduce solar power by about 5 percent in California and as much as 10 percent in some parts of southeastern China.
Those losses could be offset globally, by gains in other energy sources and in other regions around the world, said study co-author Raúl Cordero, a climate scientist at the University of Groningen in the Netherlands.
But in places where solar is the dominant renewable energy source, El Niño years could drive up demand for fossil fuels to compensate for the deficits, Cordero said. That, in turn, could temporarily increase greenhouse gas emissions in these regions.
That’s important calculus for states or countries striving to reduce their carbon footprints on certain timescales. California, for instance, is aiming to achieve net-zero emissions by the year 2045.
“For the next 12 months, probably, we will see a spike,” Cordero said of emissions.
Hydropower
Just as El Niño can increase cloud cover and dampen solar energy generation in some regions, it can clear the skies and dry up hydropower in others. It’s a “signature of El Niño,” said Boscolo of the WMO.
Previous events have had dramatic consequences in countries like Colombia, where hydropower supplies up to 70 percent of the nation’s electricity. A strong El Niño in 2015 and 2016 caused water levels in the country’s dams to drop by as much as 60 to 70 percent, according to a report from the World Energy Council. Hydropower generation also dropped across other parts of the continent, including Brazil and Ecuador, as one of the worst droughts in decades choked the region.
It’s not just South America at risk.
Some hydroelectric-reliant areas in southern Africa are also prone to drought during El Niño events, Boscolo said. Hydropower production in the U.S. Pacific Northwest is also negatively affected, alongside parts of Central and South America, Southeast Asia and southeastern Australia, according to a 2017 study.
El Niño events can also cause temporary spikes in fossil fuel demand. A report from the U.S. Energy Information Administration found that a strong El Niño in 2015 suppressed hydropower in Washington and Oregon, where it composes the largest share of electricity generation, resulting in “an increased reliance on natural gas and other fossil generation to meet electricity demand.”
Wind
El Niño’s effects on solar and hydropower generation tend to be straightforward, driven mainly by increases or decreases in precipitation. But for wind, it’s “more difficult to really understand the impact and the mechanisms,” Boscolo said.
Previous events have suggested there may be some predictable patterns, she added. Parts of Asia, for instance, tend to see deficits in wind power during El Niño events.
Studies on the relationship between wind power and El Niño are sparse and tend to be regionally focused, but some suggest parts of the U.S. could be affected. A 2024 study of renewables in Texas found that both solar and wind power supplies tend to decrease under El Niño conditions.
Ensuring reliability
El Niño is a natural climate cycle, typically recurring every two to seven years and lasting for about a year. But studies suggest that human-caused climate change may be worsening its effects, causing severe events to happen more frequently with stronger impacts.
That means grid operators worldwide should be planning for stronger El Niño events in the future, Boscolo said. Diversifying the energy portfolio is one way to do that, ensuring that the grid isn’t overly dependent on any one source.
The importance of a diverse energy mix is often cited by oil and gas executives as a reason world leaders still need fossil fuels. But climate scientists and energy analysts say combining multiple renewable energy sources can provide reliable electricity generation while supporting the Paris Agreement’s international commitment to transition away from fossil fuels.
“When we talk about renewables, we have three different technologies that could be complementary,” Boscolo said.
Meanwhile, she said, this year’s El Niño — which some scientists say could strengthen into a record-breaking event — will provide more useful data on the under-studied relationships between the natural climate cycle and global renewable production.
It’s a subject that’s gaining scientific interest as renewable energy capacity continues to expand worldwide, said Cordero of the University of Groningen.
In the past, “most of the research related to El Niño was related to the effects of El Niño on precipitation, change in drought frequency or severity, things like that.” Cordero said. “But now the energy is moving in the right direction, and you cannot ignore anymore the effects of El Niño and other naturalizations on renewables.”
