The heat wave currently baking the Western U.S. has produced a record high — 133 degrees Fahrenheit — in Death Valley and triggered rolling blackouts affecting millions of Californians. With demand for electricity threatening to exceed supply, the state sought extra capacity from producers in Washington and Arizona, but those states also faced soaring temperatures and spiking demands. Making matters worse, cloudy conditions and faltering winds cut the energy coming from several large solar and wind generators. Power grid managers in California chose rolling blackouts to avoid a more serious systemic failure.

Extreme heat is the proximate cause of California’s current trouble. But behind this lies the increasing pressure that global warming is putting on power systems everywhere. The recent explosive growth of renewable energy sources may help keep temperatures from rising even faster, yet it also makes managing the grid more complex, as it requires integrating diverse energy sources subject to the fickle whims of clouds and winds. Rising temperatures and more extreme weather also make those sources increasingly prone to disruption.

Renewable energy offers great hope for avoiding the worst consequences of a warming planet. Yet it’s a massive challenge to redesign the existing grid — much of it decades old and built for fossil fuels — so it can efficiently utilize this energy. In coming years, the challenge will only be compounded by rising temperatures.

Cultural anthropologist Gretchen Bakke of the Max Planck Institute for the History of Science in Berlin touched on the problem in her 2016 book “The Grid,” which examined the history of the U.S. electrical grid and the complex interplay of technological, political, financial and cultural forces shaping its evolution. She suggested to me in a recent phone interview that the most pressing challenge is to find ways to run a grid reliably when its power comes not only from central generating stations, but also from millions of distributed generating sources such as rooftop solar panels.

Many areas around the world have seen a surge in renewable energy capacity in the past decade. Yet if many individual sources send power to the grid at the same time or go online together, these coordinated changes lead to voltage surges that can damage power lines and transformers, while dips in supply lead to brownouts and blackouts. Energy generation from natural gas or fossil fuels can be turned on or off on demand, but small photovoltaics only produce energy when it’s sunny.

“One tiny puffy white cloud can produce a dip across a whole region as it moves over multiple rooftops,” says Bakke. “And since electricity use and production have to be balanced all the time, this makes everything unstable. The current grid is simply not made to work this way.”

For this reason, a significant amount of renewable energy capacity hasn’t been incorporated into the grid as it might have been, with California being a prime example. The state passed a law in 2015 requiring 50% of all electricity in the state to come from renewable sources by 2030. However, after lawmakers were pressured by utility lobbyists, the law only counted energy coming from large producers running centralized stations, excluding rooftop solar from individual homes. This despite the extremely rapid growth of such capacity: As of 2015, rooftop solar was producing three times as much as centralized stations.

An amendment in 2018 changed this, allowing the inclusion of essentially all renewable energy sources. The fact that they were first excluded, Bakke told me, reflects the general distrust energy authorities have for smaller-scale energy projects because they can bypass centralized systems management.

“The right path would have been the more difficult one — to ask the utilities to work out a system whereby all renewable power was counted and integrated in the 2030 goal,” Bakke says of the 2015 law. “There’s a ton of rooftop solar available.”

As if the complexity of the emerging grid weren’t enough, the problems facing energy producers will grow worse with as temperatures rise. Mikhail Chester, an associate professor at Arizona State University’s School of Sustainable Engineering and the Built Environment, points out that much of the current U.S. electrical grid was built decades ago and designed to cope with temperatures and environmental conditions typical of the past three or four decades. As temperatures rise, the efficiency of both energy generation and distribution is likely to suffer — power lines can’t dissipate heat quickly enough, and components fail more frequently. In a modeling study of Arizona’s grid, Chester and colleagues estimated that every 1-degree-Celsius rise in temperatures will make key power-system components fail three times as quickly and make cascading power outages 30 times more likely.

Hence, there’s an urgent need to figure out how to re-engineer the grid to be more resilient even as the climate becomes more unstable.

“How to do this is the trillion-dollar question,” says Chester, “and there’s no clean answer at this point. The science and engineering are emerging; the question is, Are they emerging and being implemented fast enough?”

As in California, we’re likely to see encouraging surges of success in implementing renewable energy, followed by unanticipated failures, as a diversified power industry — along with millions of individual energy producers — feels its way by trial and error toward an electrical grid able to cope with an uncertain climate future.

What’s clear, notes Bakke, “is that we cannot continue to make electricity from fossil fuels. Because of climate change, it just keeps getting hotter and harder. So we have to find a way to do it with renewables. In California, our efforts are currently failing, and maybe, in the end, we will fail.”

But Bakke is optimistic. “There are so many really smart people working to make it happen,” she says. “But we don’t know if it’s even possible — especially as climate conditions grow worse — to have an electrical grid of the kind we’ve been used to.”