Danielle Allen: Hello, and welcome to this episode of Naked Nuclear. I'm Danielle Allen, and today we're talking about something that I decided to ask the internet. So I came across a post that was asking why California would need nuclear if they already have solar plus battery energy storage systems, and it got complicated.

So, as you might've noticed, this season is all about understanding how to build a nuclear power plant, but I wanted to make this episode to answer the question, why are we building nuclear power plants? So I did something I've literally never done before. I asked the internet a simple question if solar panels and batteries are getting so good.

Why would California ever need nuclear energy? And within minutes, people started arguing, engineers, scientists, energy people. Some were thoughtful, some were less thoughtful, but buried in all of that noise was a really solid question, which was what actually keeps the lights on. So let's get started.

Let's start with what most people think. Solar panels make electricity during the day. Batteries store extra energy problem solved, right? Not quite, because electricity isn't like food you can store forever. It's not like your grandma's jar of peaches that you just put onto the shelf and they stay there.

It's more like oxygen. You breathe in when you need it, you breathe out when you don't sort of. And you need it timed appropriately, not earlier, not later. And that really changes the way that we think about energy.

So if the power grid isn't built for a perfect sunny afternoon, it's, understanding. The worst hour rule is if we need energy, when we need energy, like we need it, when we need it. The power grid cannot be built for a perfect sunny afternoon. It has to be built for the worst hour of the year. and that could be a hot night when everyone's AC is blasting a cloudy stretch where solar drops or when the wind just disappears.

And this is where the idea of dispatchable power comes in. So dispatchable power is power You can turn on whenever you need it. Whenever demand increases, you can meet that demand. And one of the clearest points from one of the comments was:

" the grid needs a substantial portion of this generation to be dispatchable".

Solar and wind are amazing, but they don't follow your schedule. They follow the weather. So you're thinking, okay, what if we just store the energy? And that's where batteries come in and batteries absolutely help. But here's the catch.

Batteries today, store energy for, you know, a few hours, days, weeks, and definitely not entire seasons.

One comment summed it up really well, covering a grid could require something like one terawatt hour of storage, and that is a lot of batteries, which is also a really polite way of saying that's an enormous amount of infrastructure. Yeah, not just batteries, but mining, manufacturing, the global supply chain at scale that we've never built before.

It's not to say that we couldn't build it, but highlighting some of these ideas around the practicality and logistics of just put batteries everywhere. That looks like creating the supply chains, creating the mining and manufacturing to be able to get the materials we need to build them.

The last 10%. So we're talking about batteries, we're talking about solar. We're like, okay, this is great. We put them together, we are solid, but here's where things get tricky. If we're trying to get to 70% or 80% clean energy with wind and solar, it's very doable. But getting to 100%. Uh, that's where everything gets really expensive.

If you go back to season one, I have an episode with Dr. Simone Friedrich from the University of Gro and we talk about the philosophy of economics. Around energy systems, and one of the points he brought up is that last 10% becomes very expensive to get solar plus batteries to a hundred percent reliability, 24 7 on the grid.

Because now we're trying to cover the worst weather, the longest nights, the highest demand spikes, and as one person put it in the comments, " that last 10% is getting really expensive," and most public conversations just kind of skip over that part because it makes things a little bit uncomfortable.

So now that we're uncomfortable, we're talking about solars plus batteries. Let's talk about reliability versus cost. And I think of this from an engineering perspective, but also from a firefighting perspective.

In a major city you don't want a fire crew or a fire truck only available 90% of the time, and then they just clock out. So One of the most consistent ideas from engineers in this discussion was, if you want power, you need it to be there 24 7. And that sounds obvious until you realize most of the energy conversations focus on cost per unit of electricity, not whether that electricity shows up when you need it, because to me.

Cheap electricity at the wrong time is basically useless. Hospitals don't care that power was cheap at noon, if it disappears at midnight and all of their ventilators stop working. This is one of the conversations that we're going to be having with Zion Lights how energy is life and how the most successful countries have access to abundant energy. It's our job now to make it clean and reliable,

so. One other thing that we talked about within the comment section was this idea of capacity factor. So we want energy that's there 24 7, and to do that we have to break down capacity factor, which means how often something is actually producing energy in the United States. Nuclear runs about 90% of the time.

Solar runs close to 20 to 25% of the time. That doesn't mean solar is bad. It just means that you either need more solar and you need something like batteries backing it up because again, The grid doesn't care about the potential, it cares about the reality and the reality of the situation is that across all forms of energy generation, nuclear is the only generation form that is in that 90% capacity range.

Here in North Carolina. Duke Energy just posted their stat that they had reached a 96% capacity factor. That means that 96% of the times their nuclear plants were generating electricity, which is outstanding.

lastly, one of the comments talked about something that I think. It is really difficult when you don't have a background in energy systems when it just feels like you get your power from the plug in the wall, and that's that. If there's a blackout, you no longer have power.

Oh, well, so sad. Too bad. But we don't learn about the very things that are keeping us alive. And one of the points that usually comes up around grid and grid stability is grid inertia. So imagine pushing a heavy spinning wheel, okay? You can't imagine pushing a heavy spinning wheel because you probably have never pushed a heavy spinning wheel, because this is not the 1700s.

however you maybe have ridden a bike, okay? So you're riding a bike on completely flat ground. You're maybe like. 16 years old hanging out with your friends. You haven't yet gotten your driver's license and you guys are zooming you try to be the cool kid. You take your feet off the pedal, do you stop?

No. Your bike keeps spinning. It's that inertia, the necessity to keep moving forward, to keep that motion happening that keeps those wheels spinning.

But really, once something is moving, it wants to keep moving. That's inertia. Power plants like nuclear and hydro use big spinning machines and those spinning machines store energy and that helps keep the grid stable.

So if something were to suddenly change, like a power plant goes offline, that spinning energy in that turbine gives the grid time to adjust solar panels and batteries. They don't spin. They connect through electronics, which means that they don't naturally provide, that same stabilizing effect. However, there is new grid technology coming out to improve that, but as we add more solar and batteries, we actually lose some of that built in stability and we have to recreate it artificially, which is possible, but not simple, and also not free.

So when we talk about energy, we're not just talking about replacing the energy and electricity, we're talking about replacing how the grid behaves, reshaping the system entirely.

So within the post that I highlighted, and I'll link it below in the show notes, the question posed is, what's the point of nuclear? So when people step back from arguing, the clearer picture started to form nuclear power it runs day and night. It doesn't depend on weather, it produces a lot of energy in small spaces, and it helps stabilize the grid.

The key number that stood out is that nuclear operates around 90% of the time. When we're looking at solar plus batteries, we're looking at the idea that it one day could operate 90% of the time, not that it already does.

That's really important and one comment points that out is the reality that nuclear is already meeting the needs of our population versus the idea that solar and battery can one day help us get there.

Because when we start to put things online, when we start to really engineer solutions, one of the things we need to realize is that the idea of 90% capacity factor. And the reality of a 90% capacity factor are two completely different things.

One's on paper, one's boots on the ground. And the nice thing about nuclear , is these are 90% capacity factors with engineering that was originated in the seventies for most plants.

So if you think about what we could do today with improved technology. That's why Duke Energy hitting 96% capacity factor is really exciting. It's not just about energy, it's about the idea of reliability 24 7.

So to me, I like an all of the above approach when we're thinking about energy systems because I've worked in natural disasters, when you need energy and you need it fast. Diesel generators get deployed, solar comes in. We need things that are easily transportable, boots on the ground, and it gets there fast.

But when we're looking at systems that need to be stabilized on a mass scale, that's where nuclear comes in. So to me, the real fight it's not just what's the point of nuclear? Can we get it done with solar? It's about trust, cost, and identity. Some people don't trust nuclear because it's expensive. Projects have gone over budget. Other people don't trust solar only systems because they worry about reliability and what happens in a worst case scenario. And when people argue about energy, what they're really asking is, who do I trust to keep the lights on?

So if you are wondering why does California need nuclear at all?

It's not because solar is bad. It's because energy systems have to work even when the conditions aren't perfect, when the sun is shining, when the demand is high, when power plants go offline. So before I wrap up, I want to thank everyone who jumped into the comments on this post. Y'all brought data, thoughtful explanations and some strong opinions, but I think all of it helped surface a better question.

And that is what Naked Nuclear is all about. Stripping down today's energy topics around nuclear technology to really understand what are the solutions and turning them into something we can actually understand.

Thank you to Jason Khouri, John McClure, Ron King Thomas Mohr Chris Johns, Eric Harvey, Jonathan Raymond Ross Koningstein, Michael Burt David Dis hardens Carl Wurtz Thomas Ajee, Joe Ford, Ashley Forbes, Oscar Paulson, Dillon Allen. No relation to Danielle Allen, uh, Jesse Williams and Thomas Rausch. Thank you so much for everyone, for commenting, for providing us some answers and clarity from your experience and expertise and being able to make this episode happen. If you like this episode, please share it with a friend, and until next time, stay curious.