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We’ve covered the dream of fusion before in this newsletter: the power source could provide consistent energy from widely available fuel without producing radioactive waste. 

But making a fusion power plant a reality will require a huge amount of science and technology progress. Though some milestones have been reached, many are yet to come. At our EmTech MIT event this week, I sat down with Kimberly Budil, director of the Lawrence Livermore National Laboratory (LLNL). 

She was at the center of the science news world last year, when researchers from the national lab achieved what’s called net energy gain, finally demonstrating that fusion reactions can generate more energy than is used to start them up. 

During our conversation on stage, I asked her about this moment for fusion research, where the national labs fit in, and where we go from here. 

The moment

In December 2022, a group of scientists sat in a control room that looked like something out of a space mission. They focused 2 million joules of laser energy onto a target about the size of a pea. Hydrogen fuel inside that target began to compress, releasing energy as the atoms inside fused together. 

And this time, more energy came out than what went in—something that had never happened before.

“This was really just a moment of great joy and vindication for all of the thousands of people who have poured their heart and soul into this pursuit over many decades,” Budil told me on stage at the event. 

Many people thought it would never work, she explained—that the lab would never get to the level of precision needed with the lasers, or get the targets perfect enough to house the reaction. “The laser is a miracle, a modern engineering miracle,” she said during her talk. And “the targets are incredible, precision works of art.” 

It’s “very, very hard to make fusion work,” Budil told me. And the moment researchers achieved net energy didn’t represent the finish line, but one milestone in a series of many still to come. 

The aftermath

After the first successful demonstration of net energy gain, “the first priority was to repeat it,” Budil said. “But the next five shots were duds. They really did not work.” 

It seemed to be mostly a problem with the targets, those tiny fuel pellets that the lasers shoot at. The targets need to be virtually perfect, with no defects. Making one takes around seven months from start to finish. 

It wound up taking around six months to repeat the initial success, but over the summer, the lab achieved the highest energy gain to date. The team achieved net energy gain twice more in October. 

There’s still a lot to learn about fusion, and researchers are trying to do just that with these repeated attempts. On stage, Budil ticked through some of the questions they still had: Could the scientists make changes to the targets? Alter the laser pulse shape? Turn the energy up? 

There’s been steady progress on the science and engineering behind fusion energy for decades, Budil said, but new questions always come up as progress gets made. 

I asked her when she thought this energy source might be ready for prime time. “My best guess is that you could have a demo power plant in 20 years,” she told me. Some startups are making bolder claims than that, predicting a decade or less, “but I think the challenges are much more significant than people realized at the beginning. Plasmas are really complicated,” she said. 

Ultimately, researchers at the national lab won’t be the ones to build a power plant: that’s the role of the private sector, Budil says. But the researchers plan to keep working as part of the growing ecosystem of fusion. 

Budil counsels a bit of patience as researchers around the world work to reach the next big fusion milestone: “The fusion community is definitely known for its irrational exuberance. My job for the last year has been half to get people excited about big science and public science, and the other half is to manage expectations for fusion energy, because it’s going to be very hard.” 

Related reading

The road to this moment in fusion has been a long one. Check out some of our old magazine covers on the topic, from as early as 1972.  

The dream of fusion power isn’t going away, as I wrote in a newsletter earlier this fall.

The first net energy gain in a fusion reactor was a huge moment, but the ultimate application for energy is still many breakthroughs away.

Helion says its first fusion plant will be online as soon as 2028. Experts are skeptical of this and other ambitious timeline announcements, as my colleague James Temple covered earlier this year.

Keeping up with climate  

The US and China have agreed to work together to ramp up renewables and cut emissions. The agreement comes as President Biden and President Xi Jinping meet in person this week. (New York Times)

The first planned small-scale nuclear plant in the US is officially no more. Startup NuScale canceled plans for the project after it failed to line up enough customers willing to pay the rising cost of electricity. (Wired)

→ We were promised smaller nuclear reactors. Where are they? (MIT Technology Review)

A German flow-battery company, CMBlu, just pulled in $100 million in funding. The money is a big boon for a technology that has long struggled to bring the cost savings it’s promised. (Canary Media)

Car dealerships aren’t ready, or in some cases very willing, to sell electric vehicles. That could undermine progress on cleaning up transportation. (Washington Post)

Electrifying heating systems and other appliances in homes could be a major part of cleaning up emissions attributed to buildings. The problem is, renters might have trouble taking advantage of existing incentives for home electrification. (The Verge)

Exxon Mobil is setting up a facility to produce lithium, a key material for the batteries that power EVs. It’s a new foray for the fossil-fuel giant. (New York Times)

A new wave of startups is working to address the threat of wildfires. The field, increasingly termed “firetech,” can help prevent fires, or detect them once they start. (Canary Media)

Companies are racing to set up massive insect farms. The bugs can provide protein for animal feed, in a method that could help cut emissions from agriculture. (Washington Post)

Floods, heat waves, storms, and fires fueled by climate change are getting worse across the US. The hazards will increase unless greenhouse-gas emissions are cut quickly, according to a new report from the US government. (Bloomberg)