The Limits of Green: What Spain and Portugal’s Blackout Revealed

On a recent Price of Business show, Host Kevin Price visited with Diana Furchtgott-Roth of the Heritage Foundation. The former White House economist brought some important perspective on the recent blackout that recently plagued Portugal and Spain.

The widespread blackout that struck Portugal and Spain on April 28, 2025, left millions without power and exposed the vulnerabilities of an electric grid heavily dependent on renewable energy. Though investigations continue, preliminary reports suggest the outage was triggered by a rapid and massive drop in generation—15 gigawatts in just five seconds—causing a dangerous frequency imbalance. Much of the region’s energy mix at the time came from solar and wind, sources that, while environmentally friendly, are also inherently unstable and weather-dependent.

This event underscores the real-world limits of renewable energy. Unlike fossil fuels or nuclear power, renewables cannot provide consistent output or the grid-stabilizing inertia needed during sudden disruptions. As Europe and much of the world chase aggressive climate goals, this blackout is a stark reminder that the vision of a purely renewable grid may be technically and practically unachievable. The variability of wind and solar means they must be supported by flexible, reliable power sources to ensure system stability—particularly during peak demand or unfavorable weather conditions.

A diversified energy strategy is not just sensible, it’s essential. While renewables must remain a core part of the solution to climate change, we should accept that some reliance on traditional sources—natural gas, nuclear, or other firm power—will likely always be necessary. Energy policy must be grounded in realism, not just idealism, if we’re to keep the lights on in a decarbonizing world.

Diana Furchtgott-Roth is director of the Center for Energy, Climate, and Environment and the Herbert and Joyce Morgan Fellow in Energy and Environmental Policy at The Heritage Foundation. She is an Oxford-educated economist, a frequent guest on TV and radio shows, and a columnist for the Daily Telegraph. Diana worked in senior roles in the White House under Presidents Reagan, George H.W. Bush, and George W. Bush. She has served as Deputy Assistant Secretary for Research and Technology at the U.S. Department of Transportation; Acting Assistant Secretary for Economic Policy at the U.S. Department of Treasury; Chief Economist at the U.S. Department of Labor; Chief of Staff of the President’s Council of Economic Advisers; and Deputy Executive Secretary of the White House Domestic Policy Council.  Diana is the author or coauthor of six books and hundreds of articles on economic policy, most recently United States Income, Wealth, Consumption, and Inequality (Oxford University Press, 2021). She received degrees in economics from Swarthmore College and Oxford University.

Connect with Diana Furchtgott-Roth on social media:

LinkedIn: https://www.linkedin.com/in/diana-fr/

X/Twitter: @DFR_Economics