Nuclear Batteries: the best thing since sliced bread?

The U.S. Government is backing microreactor technology. So, it's getting something right

Notional rendering of a nuclear battery by Rob Freda, MIT. See here for more information

Yesterday, the U.S. Government made an announcement that you probably didn’t see. It contained Trumpian language about ensuring “U.S. energy dominance” and grim military messaging on projecting power and being “focused on lethality.” This was all to inform us that eight companies have been selected as eligible to receive awards to provide commercially available dual use microreactor technology at various U.S. Department of Defense installations. Despite the off-putting tone of the release, the news itself should be welcomed. Yes, seriously. Hear me out.

The Advanced Nuclear Power for Installations (ANPI) program is a collaboration between the Defense Innovation Unit, Department of the Army, and Department of the Air Force working to design, licence, build, and operate microreactor nuclear power plants on American military installations. This will help pave the way for widespread application of the technology in civilian settings. Yesterday’s announcement follows recent news that prototype nuclear batteries have been developed in both Japan and South Korea. Taken together, these developments could be the shard of light we need in otherwise dark times. Because innovations in advanced nuclear technology could be critical to unlocking the path to decarbonising our societies and combatting climate change.

First, let me back up …

Two years ago, from the Barcelona apartment I was calling home for the summer, I read a New York Times piece that caught my attention. My head was fixated on all things clean energy because I was in the midst of producing the first season of the Gridlocked podcast. The article was written by economist Paul Krugman. In it, he identified climate science denial and its weaponisation in culture war politics as a major obstacle we face in combating climate change. In the U.S., perhaps he is right to some degree. But this understates the problem. Especially when viewed from across the Atlantic, where questioning climate science is largely a non-issue (not entirely though).

The fundamental roadblock in more climate-conscious European societies is not so much climate science denial, but false environmental policy prescriptions such as the misguided concept of ‘demand reduction’ – the notion that we can energy-conserve our way out of climate change. This tired thinking is older than I am, and has never worked. Besides, even if some northern European countries did significantly reduce energy demand, so what? Global demand for energy is going up and up. Orders for new air-conditioning units are headed in only one direction, and the U.S. is not about to ditch the car as its main mode of transportation. So-called solutions such as switching off the lights when you leave a room, reducing travel or doing less of the things we love doing just won’t scratch the surface of dealing with global CO2 emissions. Small acts won’t add up to making a big difference; we need to drop the delusion that they will. Instead, we require policy solutions that politicians can sell to their electorates.

This means stopping our ignorance about what different energy technologies can actually deliver; stopping our slavish preference for deploying some energy technologies over others. As I argued in a Salon essay I wrote back in that same Catalan summer, too many of us are fixated on intermittent and unreliable wind and solar energy, which just tends to result in a continued reliance on gas and coal.

Instead, we should be focusing on maximising clean, low-carbon energy supply and consumption across our economies, including transport and manufacturing. Renewables have their place, but only get us so far. Today, more than 80 percent of global energy is still derived from CO2-emitting fossil fuels, causing emissions to continue to rise. Despite 25 years of green initiatives and promoting renewables, a quarter of the way into the 21st century we are cramming yet more carbon into Earth's atmosphere. Global average temperatures are rising: 2023 was the hottest year on record, until 2024 beat it. People need those AC units. Whether or not we’ve breached the Paris Agreement goal of limiting temperature to a 1.5 degrees Celsius increase on pre-industrial levels is a technical debate. Net zero isn’t working.

Unfortunately, Krugman himself falls into the renewable fallacy trap in his article: a classic case of an economist (whom I respect, I might add) not taking the time to get a sufficient understanding of the technology. Thankfully some of us – myself and Krugman included – are not required to be technical experts. We can leave that to the engineers. But we really ought to furnish ourselves with a thorough enough understanding of the extent to which these technologies can actually meet our clean energy needs, and deliver on the policy arguments we make.

A mix of demand reduction and the mass proliferation of renewable energy will not solve climate change. In the middle of the 2020s, the rational environmentalists among us have come to realise that the only way we combat climate change is through nuclear as the linchpin of our low carbon energy mix. Nuclear is the safest, most reliable, concentrated, efficient and carbon-free energy source available to us. But its benefits go beyond merely generating clean power. By deploying nuclear energy as a central part of a strategy to unlock the potential for a new and resilient energy-industrial model, the global economy can transition out of its current fossil fuel dependency and create prosperity in any location.

A clean energy revolution is required and this means getting real about how we deliver the sustainable energy systems that will help us decarbonise our economies and create viable societies for the future. This is our calling: to ensure that our children and grandchildren can inherit a liveable planet.

In order to decarbonise a society, we need to look at major sources of CO2 emissions, by sector, across the entire economy. In most economies, electricity power generation rarely goes above accounting for a quarter of emissions – and can be lower still, even in industrialised countries. We need an energy technology that can enable us to reduce emissions from our transportation, buildings, industry and agricultural production. Large nuclear reactors, typically with an output of around 1,000 MW, are great for providing reliable and clean electricity for the grid and can help us clean up the above sectors insofar as they use grid-generated electricity – for example, by powering our homes, offices or electric vehicles by nuclear-produced electricity. But there are limits to the reach and application of grid-supplied electricity.

As this paper highlights, the expansion of the electricity grid has overlapped with increasing urbanisation. This has produced a highly interconnected yet creaking system which requires tight controls over electricity generating fuels – including natural gas, coal, oil, uranium – and their transport by pipeline, truck, or rail to large centralised power plants. This has required lengthy power lines for distribution, and supply and voltage synchronisation to deliver energy to end users. At every step, inefficiencies are introduced, whilst harmful carbon emissions are added to the atmosphere one way or another. The recent addition of variable renewables has simply added further complications. Renewables can play a role in decarbonising the grid if combined with clean nuclear, but they contribute to vulnerabilities in systems that are already fragile and susceptible to external pressures. Wind farms and solar arrays are proving especially vulnerable to extreme weather events like hurricanes and tornadoes.

By contrast, advanced nuclear technologies – from small modular reactors (SMRs) to microreactors – offer solutions to so many of the challenges we face without these drawbacks. Microreactors enable us to move away from a centralised electrical grid model and provide incredible possibilities not simply to decarbonise, but to change the shape of industrial production and totally transform currently left behind communities and regions. Indeed, a new breed of microreactor called nuclear batteries (NBs) could just be the best thing since sliced bread, as the expression goes. They are probably also the best thing you’ve never heard of.

Nuclear batteries use standardised simple designs with few moving parts, combining a small nuclear reactor and a turbine to supply significant amounts of heat and power (on the order of 15–30 MWt or 5–10 Mwe) from a very small footprint. This is an energy output equivalent to that of a huge solar field or wind farm, but requiring only a fraction of the land use.

Image by Professor Carlo Ratti, MIT

Nuclear batteries are unobtrusive and can be built into the landscape or even hidden within buildings and structures. Embedded intelligence and advanced (remote) monitoring systems enable semi-autonomous, digitally secure operation. However, the wonder of NBs is not so much in the technology itself – ingenious though it is – but in how they can be deployed. They could more efficiently and reliably heat and power a Midtown Manhattan block, development of 7,000–8,000 homes, airport campus, shopping mall or mid-size data centre.

The NB is a small but powerful stand-alone energy platform that can be directly integrated into manufacturing functions or industrial plants. It’s a solution bypassing the need for massive, low-use centralised infrastructure such as the national grid, energy storage, and fuel distribution networks. NBs can be factory-fuelled to operate for 5-10 years, powering virtually anything with no need for continuous fuel supply. After this, they are ‘recharged’ with low-enriched uranium fuel. They can be safely shipped back to a centralised facility for this refuelling and refurbishment at the end of the operational period, without the need for the user to handle the refuelling.

Unlike the better-known SMR, NBs are transportable ‘plug-and-play’ microreactors that can be shipped to even the most remote off-grid locations. They are fully contained, independent and – unlike traditional nuclear reactors – do not require water for cooling.

Whilst innovative, this concept is not actually new. As far back as the early 1950s, arguably the first small, self-contained, portable nuclear reactor came into being as U.S. Navy nuclear powered submarines. In the early 1960s, the U.S. Army designed, built and tested ML-1, a 500-kW gas-cooled microreactor that could be hauled around by truck and provide power in the field for over one year without refuelling. Of course, today’s NBs being developed by U.S. companies Westinghouse, X-energy, BWXT and others are a world away from that technology. Regulatory approval for models being developed would unleash to market a revolutionary innovation that can provide on demand, clean, economic, resilient and safe energy in any location. They offer a new type of distributed energy source that is low-carbon, compact, stable, flexible and geographically unconstrained.

Certain industrial processes, for example those concerning chemicals, food and other manufacturing activity, require heat in addition to electricity. Unlike electricity, heat cannot be transmitted over long distances and needs to be generated relatively close to where it is consumed. This is where NBs really come into their own. By being co-located with the heat user, microreactors can totally transform the geography of industrial structures and elevate manufacturing to an advance level of production. Large energy plants will likely continue to form the backbone of our energy infrastructure, of course. But unlike large reactors, large wind or solar farms, NBs can provide any desired amount of electricity and heat on site, eliminating the need for long-distance transmission and large centralised infrastructure.

NBs avoid many of the drawbacks associated with the costly and protracted construction of larger power plants. Indeed, large labour-intensive construction sites can be avoided altogether via prefabrication of NBs in a central manufacturing facility before delivering them in one piece directly to the end user location, where they can be plugged in and made operational within a matter of weeks. This reduces cost that would only fall further, dramatically in fact, through economies of scale as orders for NBs increase.

NB technology is at advanced development stage and can be ready for market by 2027-2028, according to industry estimates. I’m informed by those developing NBs that, within the first few years of mass production, the cost of each battery would come down to between US $50–$80million, excluding the fuel costs. This would circumvent the need for decades-long, multibillion-dollar construction projects and ought to be an attractive proposition for investors who can see their financial risk significantly reduced.

While the cost of each microreactor is low in absolute terms, it is likely the unit cost of energy generated by the NBs will be higher than SMRs and large reactors. However, NBs will be competitive because they will be used in markets where the competition is either diesel generators or non-existent.

This video of the Westinghouse eVinci™ shows how nuclear batteries could be deployed

We are at a point in history requiring us to avert climate breakdown whilst breaking through stalled ideas and socio-political divisions. One way we can do this is through setting our ambitions higher, by looking to completely change the way our economies are structured. And this is where the real beauty of NBs is seen: in their transformative potential to propel us into a new industrial revolution. By coupling them with advanced production procedures requiring consistent localised energy – from containerised modern farming facilities to advanced chemicals – how and where we manufacture the products of the future can be totally revolutionised. Remote rural economies, commodity dependent regions, developing and smaller nations could all have their economic destinies handed to them like never before.

It gets better still. In addition to helping us mitigate climate change (i.e. cutting emissions and slowing the pace of global warming), microreactors could just be the sharpest item in our climate adaptation toolkit. If the recent wildfires and hurricanes have taught us nothing else, it is that we need to better protect ourselves from climate consequences already on our doorstep.

Take the problem of melting ice caps and rising sea levels as an example. Across the globe, coastal communities are having to construct significantly upgraded sea defences. Increasingly these communities – especially islands – will require dykes and barriers to shield them from the higher sea levels. The controlled inner waterways and lagoons being created will require water to be pumped, in places almost continuously, in order to prevent devastating flooding. This will require a large amount of steadfastly reliable energy. Off-grid microreactors are the perfect solution.

As scarcity of fresh drinking water becomes an increasing threat to parts of the world, a single NB could provide enough desalinated fresh water for over 150,000 people. Indeed, with severe weather events and the impacts of climate change leading to the displacement of increasing numbers of people, NBs could be quickly deployed to provide energy in disaster relief zones.

All of the above is possible from a battery system small enough to fit within standard shipping containers (as the video above shows). A 2021 research paper led by MIT’s Center for Advanced Nuclear Energy systems highlights how much material could be saved by using NBs instead of other, less reliable, clean energy alternatives:

To build a windfarm of 100 MW requires about 20,000 tonnes of steel, 50,000 tonnes of concrete as well as 900 tonnes of plastics used in the blades. Solar photovoltaic farms producing similar outputs require 50% more materials, though less steel than wind. In contrast, NBs generating 100 MW would require around 20 tonnes of low-enriched uranium, 1,600 tonnes of steel and 4,600 tonnes of concrete.

Microreactors and NBs offer a society greater control of its economic destiny, building a more sustainable and prosperous future through technological solutions that can provide on demand, clean and reliable energy in any location. NBs really could be the most exciting innovation in decades … Yet virtually nobody outside the nuclear energy community is talking about them.

So, we need to change the conversation and, as we look ahead to a clean energy future, try to imagine a world without polluting power stations burning fossil fuels. A future landscape without pylons and grids. A world where acres of countryside and essential farmland are not surrendered to metallic rows of solar panels, containing toxic waste that will go into the ground somehow.

Imagine a future in which our planet’s precious ecosystems are protected, where the variety of natural life on Earth – our rich biodiversity – is preserved and secured. Imagine a future of resilience to floods, droughts and extreme weather, where talk of net zero targets is a thing of the past. Imagine a future world where we can ‘plug and play’ clean energy anywhere, whatever the business.

Imagine a world where economic prosperity is no longer the preserve of those living in large urban centres in already industrialised regions. Imagine a new globally shared equity that ends previous commodity dependency and lifts our left behind communities and regions out of poverty.

Well, imagine no more, because we don’t have time to waste. We must step forward into the future, starting today. To paraphrase Neil Armstrong, one small nuclear battery can create one giant leap for mankind; enabling us to build a world for our children and grandchildren that is worth inheriting. If we usher in the nuclear renaissance, with advanced microreactor technology at its core, we can create tomorrow’s world, today. So, what are we waiting for?

Further Reading (referenced above):

1. Buongiorno et al, “A Strategy to Unlock the Potential of Nuclear Energy for a New and Resilient Global Energy-Industrial Paradigm,” The Bridge, (National Academy of Engineering), June 15, 2021. Volume 51 Issue 2: https://www.nae.edu/255810/A-Strategy-to-Unlock-the-Potential-of-Nuclear-Energy-for-a-New-and-Resilient-Global-EnergyIndustrial-Paradigm

2. Buongiorno et al, “Can Nuclear Batteries Be Economically Competitive in Large Markets?”, Energies 2021, 14(14), 4385; https://doi.org/10.3390/en14144385