California's Rolling Blackouts: Causes and Remedies

When the first rolling blackouts in two decades struck California late last week, many were quick to invoke an earlier California electricity crisis and look for a convenient villain. But we need first to understand exactly what happened and to appreciate how much worse it could have been, even as we work urgently to address the underlying problems and continue a clean energy transition in which reliability is a cornerstone.

iStock/Komarov Vitaly

Any large-scale electricity service interruptions threaten public health, equity, and economies, and this one sends a clear warning last heard by millions during the 2001 crisis: we must do more to preserve reliable electricity service, with emphasis now on “extreme” weather events exacerbated by the climate crisis. And we must double down on the clean energy solutions that address that crisis head-on, by cutting the carbon pollution emissions at the heart of the problem.  

California and the West are confronting a massive region-wide heat storm (the worst since 2006) that continues to boost power demand and strain electricity supplies, although so far the power has mostly stayed on. Service interruptions that began on Aug. 14 have thus far lasted two hours at most, moving neighborhood by neighborhood across California in a process carefully controlled by grid operators.

Compare that to what happened on an earlier August 14, during what came to be called the Northeast Blackout of 2003. There, some badly managed vegetation near Ohio power lines on a warm (but not unusually hot) summer afternoon crashed entire regional grids and left 50 million people across eight states and Canada in the dark for at least 24 hours (some for weeks).  

Those afflicted by this month’s outages constitute a small fraction of those who suffered through the Northeast blackout. That’s both because California’s grid is much better managed and because we are interconnected with a giant west-wide power system; for example, daily in-state electricity shortages of 500 – 4,500 megawatts at peak hours would be far worse if our neighbors in the Pacific Northwest hadn’t kept the 8,000-megawatt interregional transmission system largely filled with hydropower exports. Full western grid integration would increase those benefits significantly.  

What History Tells Us

As NRDC noted during the earlier California electricity crisis in 2000-2001, the cheapest, fastest and cleanest solutions involve electricity demand reductions in three major categories: responses to voluntary appeals to avoid, delay, or cut electricity use during the periods of greatest electricity system needs; hard-wired long-term upgrades to the energy efficiency of buildings and devices; and equipment adaptations and controls that ensure greater flexibility in electricity use. While we’ve made significant advances since then in California’s clean energy inventory, in both demand reductions and renewable energy additions, there is plenty of unfinished business.

My colleague Mohit Chhabra recently outlined priorities for ramping up statewide energy efficiency, and the California Energy Commission is working right now on standards that should boost the flexibility of electricity use by more than enough to handle another heat storm like the one we’re experiencing now. 

In 2000-2001, California households and businesses responded to statewide appeals with almost 5,000 megawatts of voluntary demand reductions, which would be more than sufficient to overcome the current supply shortfall if fully tapped again. A wide range of storage technologies, including efficient electric appliances, vehicles and batteries, are also part of a diverse portfolio of solutions. And we need much more coordination of long-term resource procurement among an increasingly fragmented group of California electricity providers with collective responsibility for maintaining statewide resource adequacy (including both traditional utilities and Community Choice Aggregators).

Demand-side management and enhanced western grid integration will help us maintain system reliability and minimize costs by coordinating power reserves and squeezing all the work possible from our growing fleet of renewable energy generators like wind and solar. And they, in turn, benefit from geographical diversity that balances a cloudy day in the California desert with more favorable conditions for solar generation elsewhere. That’s a far better and cheaper reliability strategy than running dirty emergency diesel generators on hot afternoons (often in densely populated places).

And while these are being turned on now to keep the grid from crashing, we need to take steps to make sure they aren’t a permanent part of the landscape. We don’t need to trade our treasured air quality safeguards for reliable electric service.

Some are already blaming California’s Independent System Operator (CAISO) for the recent outages, but in recent years the CAISO has warned repeatedly of looming reliability issues and now has moved swiftly to minimize the damage, in cooperation with grid managers across the vast expanse of a severely overheated western region. No one is happy with rolling blackouts. Neither should anyone assume that they are an inevitable part of summer in the West (or anyplace else). We have a host of clean energy tools to prove otherwise.

About the Authors

Ralph Cavanagh

Energy Co-Director, Climate & Clean Energy Program

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