COP28 pledge to expand nuclear capacity is out of touch with reality


The 2023 Conference of Parties (COP) climate change summit held in Dubai in December ended with a call to contribute to a transition “away from fossil fuels in energy systems.” The discussion at the COP about how to replace fossil fuels included two pledges. One was ambitious but within the realm of possibility. The other pledge was plain wishful thinking. The first, signed by 123 countries, was enshrined in the final COP28 document. The second was unofficial and attracted only 25 countries. One concerned renewable energy and energy efficiency, the other, nuclear energy. No prizes for guessing which pledge corresponded to which energy source.

M. V. Ramana.

Image: University of British Columbia, Vancouver

Historical trends can help us understand why a goal of tripling nuclear energy generation capacity by 2050 is unattainable. According to the latest edition of the “World Nuclear Industry Status Report (WNISR2023),” the operating power generating capacity of all nuclear plants in the world is 365 GW, as of July 2023. Tripling this by mid century, 27 years from now, would mean close to 1.1 TW of nuclear capacity.

Twenty-seven years ago, in 1996, the world had 344 GW of nuclear generation capacity. Since then, when the capacity added by new nuclear reactors is tallied and that of old reactors that have been shut down is subtracted, the global nuclear fleet has grown an average of 800 MW per year. At that rate, nuclear capacity in 2050 would be a mere 386 GW, assuming that a large number of reactors would be built to replace the aging nuclear fleets of most countries. In other words, the likely nuclear capacity in 2050 would be a mere fraction of what is desired by the COP28 pledge.

Falling share

A second trend should also be acknowledged. Since 1996, the share of global electricity produced by nuclear reactors has declined from 17.5% to 9.2%, according to “WNISR2023.” That is in stark contrast to the corresponding trends for renewables, especially solar and wind energy. Between 1996 and 2023, the share of global electricity produced by modern renewable forms of energy has grown from 1.2% to 14.4%, according to the Energy Institute’s “2023 Statistical Review of World Energy.” The actual increase in the amount of energy produced by renewable sources is even more dramatic because the total energy flowing in the world’s electricity grids has more than doubled over that period.

The phenomenal growth of renewables is fueled by an even more astonishing decline in the cost of generating solar and wind power. Between 2009 and 2023, the levelized cost of generating electricity from utility scale photovoltaic farms and onshore wind farms in the United States has decreased by 83% and 63%, respectively, according to the “2023 Levelized Cost of Energy+” report published by Lazard. Nuclear electricity costs have escalated by 47% over the same period.

For recently constructed reactors, each gigawatt of generation capacity costs around $15 billion, meaning a bill of around $11 trillion to build the 730 GW needed to triple current capacity. The cost would be even more when taking into account the need to replace some of the old reactors shut down over the same period.

Nuclear advocates would likely disagree with this analysis and these numbers, arguing that building lots of reactors would lower the cost per gigawatt of generation capacity because of learning from experience. On the contrary, the cost of building nuclear plants has typically gone up as more have been built. In the United States and France, the countries with historically the largest nuclear fleets, and reliable costing information, the most recent reactors, Vogtle-3 and -4 in the US state of Georgia, and Flamanville-3, in Normandy, are the most expensive ones built in those countries.

Popular content

Some nuclear proponents argue that small modular reactors (SMRs) will change this picture. These will not benefit from economies of scale, however. A reactor that generates three times as much power as an SMR will not require three times as much concrete or three times as many workers. As a result, building and operating SMRs will cost more than large reactors for each megawatt of generation capacity. In turn, the electricity from small reactors will be more expensive than electricity from bigger sites, as was seen in the case of the many small reactors built in the United States before 1975. Those were financially uncompetitive and shut down early.


The higher cost per unit of generating capacity was also seen in the case of the proposed NuScale reactor, which was planned for Utah, in the United States. The now abandoned project, which was to be developed by NuScale for electric utility Utah Associated Municipal Power Systems, would have involved six SMRs with a total generation capacity of 462 MW for an eye-popping $9.3 billion. At that rate, building a gigawatt of nuclear capacity would cost $20 billion, not $15 billion.

That cost would likely have been greater if the project had actually gone ahead and the reactor was built. Historically, nuclear reactors have routinely exceeded initial cost estimates, with one paper, published in scientific journal “Energy,” finding 175 of 180 nuclear construction projects had experienced cost increases and delays. The authors of that 2014 paper found cost escalations averaged 117% and construction took 64% longer, on average, than projected. The cost of the Vogtle project rose from an estimate of $14 billion, when construction of the two AP1000 reactors started – according to news service CNN Money – to more than $35 billion, reported website Energy Intelligence.

M.V. Ramana is the Simons chair for disarmament, global, and human security, and a professor in the school of public policy and global affairs at the University of British Columbia, in Canada. He is the author of “The Power of Promise: Examining Nuclear Energy in India,” and a forthcoming book, to be published by Verso Books, explaining why nuclear power is not a solution to climate change. He is also a member of the International Panel on Fissile Materials, the Canadian Pugwash Group, the International Nuclear Risk Assessment Group, and the team that produces the annual “WNISR.”

The views and opinions expressed in this article are the author’s own, and do not necessarily reflect those held by pv magazine.

This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: