From Brussels to Washington, a new wave of enthusiasm for so-called small modular nuclear reactors (SMRs) is sweeping through policy circles, research centers, and energy startups. These compact nuclear units, marketed as plug-and-play solutions, are being pitched as the perfect answer to powering data centers, meeting the surging demand from artificial intelligence, and supporting the energy transition with clean, stable electricity.

But theres just one problem. In fact, there are many. And none of them are small.

The hype cycle in full swing

Today, SMRs are being promoted as the iPhone of nuclear energy: smarter, smaller, cheaper, scalable. A magical fix for everythingfrom remote grids to decarbonizing heavy industries to feeding AI servers. Countries like the US, Canada, and the UK have rolled out ambitious plans to deploy them. Major companies including NuScale, Rolls-Royce SMR, GE Hitachi, and TerraPower have presented shiny timelines and glowing promises.

But the fine print tells another story.

Not a single commercial SMR is operating anywhere in the world. None has even been built. NuScale, a US pioneer in this space, recently scrapped its flagship Utah project after costs soared above $9,000 per kilowatt and it failed to attract investors. Even the companys CEO admitted operations wouldnt start before 2030. Meanwhile, Rolls-Royces promised SMR factory hasnt produced a single steel bolt.

In other words, we are betting on a technology that doesnt yet exist at scale, wont arrive in meaningful numbers until the 2030s, and would require thousands of units to make a dent in global energy demand. Thats not strategyits science fiction.

Big reactors havent inspired trust either

Even large-scale nuclear projects, which SMRs are supposed to fix, are struggling. Take the UKs Hinkley Point C, once touted as the future of European nuclear power. It is now twice its original budget (over 46 billion), at least five years late, and still facing construction issues. The same French-backed EPR design has suffered similar setbacks in Flamanville (France) and Olkiluoto (Finland), where completion took more than a decade longer than promised and costs ballooned.

Lets be blunt: if any other energy technology had this track record, we would have laughed it off the table years ago.

Price floors for nuclear, ceilings on common sense

Authorities in France and Finland have now approved guaranteed minimum prices for new nuclear poweressentially handing operators blank checks. In Finland, the floor was set above 90 per megawatt-hour for 20 years. By contrast, solar and wind in European auctions are clearing between 3050/MWh, with far lower marginal costs.

So why lock ourselves into long-term contracts at higher prices in the name of a market-based future? Its hard to see how this helps consumers, industries, or climate goals. Especially since nuclear plants, like renewables, still require major grid upgrades to handle large-scale generation. No efficiency gains there either.

SMRs: too small, too late

Lets imagine the best-case scenario: some designs clear regulatory hurdles by 20272028, construction begins in the early 2030s, and the first commercial units come online by 2035. Even then, the world would need to build and connect thousands of these SMRs within 1015 years to displace a meaningful slice of fossil generation. Thats a logistical nightmarebefore even touching on public acceptance, licensing hurdles, uranium supply, or waste management.

By contrast, in the time it takes to build one SMR, solar, wind, and batteries could be deployed 1020 times over, at lower cost, faster timelines, and with no radioactive legacy.

Unlike nuclear, these technologies are already modular, scalable, and proven worldwidefrom Australias deserts to German rooftops to Californias power plants.

Inside the reactor: waste and risk

Nuclear advocates love to stress how safe modern designs are. Yes, statistically, nuclear is relatively safe per kWh. But it is the only energy source that carries a nonzero risk of catastrophic failureand waste that remains toxic for thousands of years.

So why gamble on this when we have abundant clean energy with zero explosion risk and recyclable or inert waste?

A supporting role, not the main act

To be clear, nuclear will likely continue to play some role in the energy mix for certain countries. France and Sweden have existing fleets. New builds may proceed in China or South Korea, where costs and planning are tightly managed. But for most of the world, especially those racing to decarbonize quickly, new nuclear is not the solution.

SMRs, despite the marketing, wont save the day. At best, theyll be a niche technology for specialized casesremote mines, military bases, or industrial clusters with no alternatives. Thats fine. But lets stop pretending theyre the silver bullet for energy.

Final word

We are in the decisive decade for climate action. Every euro, dollar, or yuan must deliver the maximum emissions cuts per unit of time and cost. By that measure, SMRs fall short. Nuclearlarge or smallis too expensive, too slow, too risky, and too narrow to drive the energy transition.

Its time to dial down the nuclear hype and double down on the technologies already winning: wind, solar, batteries, heat pumps, grid flexibility, and green hydrogen. These arent dreams. Theyre being deployed today, by the gigawatt.

SMRs are interesting, yes. But when it comes to decarbonization, we dont need unicornswe need workhorses.