There is no question that the world’s dependence on non-renewable fossil fuels has to end at some point. Apart from the fact that we’ll run out eventually, it’s also destroying the environment in a way that may not be reversible.

Renewable energy – a mix of solar, wind, and water power – seems to be the answer to this crisis. However, it’s not the only competitor looking to replace our dinosaur-burning habit. Nuclear energy is still on the table, despite what many people might think. Renewable energy has plenty of problems of its own, so how does nuclear technology stack up? Should the world put its energy into the atom or go with the more natural option? The answer isn’t as clear cut as you might think.


One of the biggest reasons the average modern citizen may feel a little uncomfortable with the idea of nuclear power is the perceived danger of it. Who can blame them? Chernobyl, Three Mile Island, and Fukushima all represent horrific tragedies that directly killed a significant number of people and caused environmental devastation to a severe degree. It’s also impossible to know exactly how much damage has been done. Some people who live close by may have cancer more frequently, and children with birth defects are more common. Millions of tiny negative effects on nature and human society will never be neatly quantified.


When nuclear power goes wrong, it goes wrong in a big, big way. However, these power stations were not state of the art, or were not built to deal with the sort of natural disasters we face today thanks to climate change. New reactor designs exist – ones which prioritize safety. For example, the South African pebble-bed reactor design essentially makes nuclear meltdown impossible. This is an example of a “passively safe” nuclear reactor. Contrast this with the type of reactors used in previous disasters – they require the insertion of control rods into the reactor core to stop the nuclear reaction. If you can’t put those rods in for some reason, you’re toast, my friends. Pebble bed reactors are not yet proven, but it shows that there are alternative solutions to traditional nuclear designs.

Solar power, on the other hand, obviously doesn’t have any such safety drawbacks. While scientists think that there may be climate change thanks to large-scale absorption of solar energy, it’s not the sort of change that would automatically be bad. Until we actually go almost-entirely solar, it’s hard to say exactly what would happen, or even if we’d ever need solar power at a scale that would affect anything.

While modern nuclear technology may end up being much, much safer than what we’ve used in the past, I think most of us would argue that solar power is the safest overall source of energy, at least when it comes to the solar panel part of the equation. We’ll get to that in a minute.

Fission vs Fusion

It should be noted that almost all of the concerns around nuclear energy deal specifically with fission technology. There are two way you can get atomic energy. One is to shoot atoms at each other, so that they knock their subatomic particles loose in a chain reaction known as nuclear fission. The other method is the same our sun uses to generate energy – you squeeze atoms together (helium or hydrogen) until they start to fuse, which causes a massive release of energy. At the core of every star we have these fused atoms, crushed together by massive gravitational forces. This allows them to burn for billions of years and is one of the main reason life on Earth is even possible at all.

Nuclear fusion technology aims to create what’s essentially a tiny star. However, we obviously don’t have enough mass to create the sorts of forces needed to fuse atoms. So scientists have tried using powerful lasers to create fusion instead. So far all attempts at creating a self-sustaining fusion reaction have failed. However, work is ongoing and perhaps one day we’ll have clean fusion energy. If and when that does happen, this whole debate will have to be rethought.

The Cost of Nuclear and Solar Power

You’ll see a lot cost comparisons between renewable energy such as solar and traditional nuclear power. I’ll be honest with you, it looks like the numbers can be fudged any which way in favor of either side. The most straightforward discussions of cost I have seen point to nuclear as being more expensive, but once again it depends on who you ask and what math they do.

One thing that doesn’t seem to be in dispute is that solar technology is getting cheaper and cheaper. Nuclear, on the other hand, doesn’t benefit from the advancement in materials and semiconductors that’s bringing solar power into its golden age. That’s beside the fact that you can’t have a home nuclear system, which makes the comparison a bit moot for those who want to go off-grid. It’s still an important debate when it comes to providing a national grid with electricity.

solar arrays

Small Nuclear Reactors

That does bring up a very interesting question, though. Could nuclear technology be small enough so that you could have your own off-grid reactor at home? There are nuclear power source designs that are meant to give spacecraft energy while they are too far from the Sun. The nuclear reactors that power submarines are reportedly about as big as a garbage bin, although they are totally top-secret.

Toshiba has been punting a small modular nuclear reactor known as the 4S for a few years now. Known as a micro sodium reactor, this is 4th-generation nuclear tech in a (relatively) small package. Sodium is used to cool the reactor and it can be buried in the neighborhood that would use its output. These reactors are built in a central factory and then installed on-site. They don’t require the sort of constant inspection and maintenance that big plants do. It’s a fascinating technology, but there doesn’t seem to be much appetite for it at the moment.

So perhaps sometime in this century we could develop small, safe nuclear reactors for home and vehicles. Never say never, but for now it’s really more of a fantasy.

Power Output and Space Requirements

There’s no contest here. Compared to solar, nuclear power output is much higher when you look at how many square meters of land you’ll have to use. Yes, solar panel technology is now way better than ever before, but you still need to cover your roof just to make enough power to supply your home. Think about that for a second – it means you need to have enough solar panels to cover every home in town to make enough power for everyone.

In contrast, a single nuclear power station can provide power for thousands of homes without having to take up all that much space. Even if solar panels doubled in their output per square meter, that still doesn’t come near to the nuclear order of magnitude. The average nuclear plant puts out about 4000 megawatts!

Nuclear Waste is Still a Problem

While nuclear energy may have many strong points, one of it’s biggest flaws is nuclear waste. In terms of sheer volume, nuclear is much cleaner than coal, which belches tons of pollution into the atmosphere. That white stuff you see coming out of a nuclear station’s towers is just water vapor. Obviously, it’s not radioactive either.

No, nuclear waste is what’s left over after all the fission has gone out of the nuclear fuel. The good news is that most of this can be recycled back into usable fuel. The bad news is that the only real motivation to do this is if fresh uranium cost too much. The end result is that there’s quite a lot of spent nuclear fuel in temporary storage facilities. In fact, there are no permanent, safe nuclear waste storage facilities as yet. So in the long term we have no real idea what to do with this stuff. An earthquake or other natural disaster could contaminate entire ecosystems and render them lost.

There have been suggestions that we should periodically launch our nuclear waste into space, as well as other radical ideas, but for now it’s a real problem without an apparent solution. That being said, high-grade nuclear fuel is going to run out eventually, which will push up the price. That could make recycling more attractive and temporarily help with the issue, although even that is only kicking the can down the road.

Can Renewables Act as Baseload?

Baseload power is power that can consistently be generated around-the-clock. One of the main criticisms of solar power and other renewables is that while they might make enough power on average we have no control over when that power is available. With a nuclear power station this is no problem at all. Once the reaction is going, it will keep going unless you put the brakes on it. Nuclear power has a problem with limiting how much energy is released rather than getting enough of it. From a baseload perspective, nuclear is pretty awesome. It has an advantage over coal stations, too. Apart from creating less atmospheric pollution, a nuclear station doesn’t need huge stockpiles of fuel; rain and general bad weather can’t affect its operation, as they can with coal deposits.

tesla battery storage

However, renewable energy storage is making the baseload argument redundant little by little. Thanks to Elon Musk’s giant battery storage facilities, a working version of which is in Australia, renewable energy generated during the day can now be stored overnight. Batteries aren’t even the only storage medium on the table. Check out my solar storage article for the detailed story, but you should know there are mechanical and thermal solutions to energy storage too.

This means that nuclear energy may not be so essential for clean baseload power either. In fact, existing nuclear stations may benefit from the same storage technologies too. Since you can’t just shut down a nuclear station on a whim you end up with power overproduction during low-demand periods.

So the short answer is that renewables can act as baseload when combined with next-generation energy storage solutions. It will, however, be some time before that technology is ready to be our main source of baseload power.

Perceptions are Powerful

I actually think that nuclear power has a future alongside renewable energy, especially if the right technological developments happen to make it safer, cleaner, and more acceptable to the world. However, none of this matters if people have an overwhelming negative subjective view of the technology. Nuclear is scary. It conjures images of atomic bombs and mutated animals. It has that “ick” factor which is almost impossible to get rid of. It doesn’t help that so much incompetence has passed through nuclear technology. As an analogy, if it weren’t for the Hindenburg, we might be living in a world of modern airships (filled with helium!), but that tragedy killed the technology in the eyes of the public. Atomic energy may be in for a similar drubbing.

Fair or not, you’ll find it hard to convince the general population that you want to build a nuclear power station near where they live. The idea of nuclear is now so dirty it doesn’t matter how safe or clean the technology might get. For now the public seems to have made up their mind.

Nuclear is Declining

Despite all the debate at cross-purposes, it seems clear that nuclear power use is in decline. According to nuclear peaked at 18 percent of world power generation in 1996. Now it’s only 11%. There are many problems with this power source that still need to be solved before it will really be clean in the eyes of the public.

For now I think renewables are going to quickly overtake other energy production methods, but as our civilization becomes much more power hungry and starts to reach the point where we’re doing geoengineering and other massive projects at planetary scale, nuclear could make a comeback as the only source dense enough to get the job done. I don’t think we’ve heard the last of it yet!