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No Clean Energy Source Is Marginal in the Quest for Net Zero

(Bloomberg) —

This month, two deeply established decarbonization technologies, geothermal and nuclear power, saw new milestones reached. Texas-based Fervo Energy demonstrated its enhanced geothermal technology is  feasible at scale , while nuclear fission reactor developer Oklo Inc. announced plans to go public via a special purpose acquisition company. 

Both developments fuse (no nuclear pun intended) past capabilities with future potential, looking ahead to an energy system of sufficiently great scale that even relatively small technologies are anything but marginal. 

To say that geothermal is deeply established would almost be a disservice to its early start, and subsequent longevity.  The first commercial geothermal site, Larderello in Italy’s Tuscany region, began operations in 1913 and is still producing power today (and in that century-plus has increased its total generation capacity from 250 kilowatts to 800 megawatts, a 30-fold increase). Geothermal in the US began not long after, and has been in Southeast Asia since the 1970s, with Chevron Corp. a major early developer. 

Thanks to improved technical know-how — including a remarkable increase in drilling productivity in regions such as Appalachia — geothermal power could feed the grid in areas once considered impossible for it to address. Importantly, it could do so in the future closer to centers of power demand than large-scale wind and solar installations, and provide always-on power in the process. 

Nuclear power makes up a remarkably consistent share of US power generation — around 20% of the national total every year for most of this century.  Taking it beyond that market share in the US and increasing its share elsewhere will require deploying more projects, clearly, but also embracing innovation. That includes smaller designs that can start up quickly and novel approaches to fuels, such as Oklo’s use of spent nuclear fuel from existing reactors. 

Read More: What’s Boosting Nuclear Power? War and Climate Change

Meanwhile, there’s a resurgence of interest in nuclear power in US universities. In a 2021 study, the Oak Ridge Institute for Science and Education found that the number of undergraduate and graduate nuclear engineering students has been rising after bottoming out in the early 2000s. The increase in recent years comes from a boom in master’s degrees and the second-highest number of doctorate degrees issued since 1966. 

Since geothermal and nuclear aren’t brand new, with both there is an echo of the Ship of Theseus thought experiment, which asks whether a ship that has had all of its parts replaced over many years is still essentially the same ship. Adapting existing techniques, expertise and materials is a feature, not a bug, of a dedicated effort to reach net zero emissions. Reusing old power plants is a start. Reinvigorating the collective decades of expertise inherent in the world’s drilling sector and its nuclear engineers is going a step further. 

If we are to get to net zero by the middle of this century, every technology for clean power generation will play an important role. It is easy to say that wind and solar will be the significant majority of global power generation by 2050 and will account for almost all renewable generation at that time. I have done so, for the simple reason that it is mathematically true. But it is not the whole story of the future of decarbonized power, either. 

For one thing, the simple statement elides the fact that as solar and wind penetrations increase, the final bits of firm power that the grid needs for reliability become very valuable. Some of that, and maybe much of that depending on the market, will come from energy storage. But not all of it, and the closer we get to a net zero grid, the more important reliable, always-on technologies become in supporting that grid and critical operations within it. 

For another, the sheer size of the future power system means that relatively small sectors will be absolutely quite large, in dollars invested and assets deployed. Meeting net zero will require a tripling of today’s power generation in 2050. Even a minor contribution to that tripling means hundreds of billions, or trillions, of dollars of investment into technologies that provide a small share of the total power mix. That is why the margin, in the future, won’t be marginal in terms of innovation or potential impact. 

Nat Bullard is a senior contributor to BloombergNEF and writes the Sparklines column for Bloomberg Green. He advises early-stage climate technology companies and climate investors. 

To contact the author of this story:
Nathaniel Bullard in Washington at

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