Elon Musk: Solar vs. Nuclear Energy

Elon Musk discusses the benefits of solar energy over nuclear energy.

Elon Musk: "I mean it's crazy to think that every square kilometre receives a gigawatt of solar energy. One square kilometre a gigawatt, that's crazy. In fact, for a lot of nuclear power stations - and I'm not against nuclear, unless it's sort of in a natural disaster zone -

Interviewer: "Maybe we'll get you working on some of our storage of nuclear waste issues."

Elon Musk: "Yeah, it's a challenging item. But if you take a nuclear power station and the whole clear area that's
around it, it ends up being quite a big clear area around most nuclear power stations, and it ends up
being quite a bit of land. And if you calculate, if you carpeted that land with solar panels, which would generate more? The nuclear power station or the solar panels? And usually it's the solar panels."

Full video here:

[bryanelliott]

Limerick nuclear generating station in Pennsylvania (my local nuke plant) generates an average of 2.17 GW. Its exclusion zone is just under 2 km². So it's getting about 1.08 GW / km². It's a typical of a site for American nuclear reactors - so typical, in fact, that 1 GW/km² is my in-my-head number for talking about nuclear land density in-person.

Now, insolation at noon on a cloudless day is about 1 GW / km² - however, it's not always noon and cloudless. On average, in my area, insolation is ~4.5 kWh/m²/day - or about 187.5 MW / km². The place with the highest insolation on earth gets an average of 6.5 kWh/m²/day - 270 MW/km². That's your best case, barring control of the weather and the rotation of the earth.

Solar panels aren't fully efficient, though. Nominally, they convert about 15% of incoming light to electricity. Meanwhile, the Shockley-Quissier limit for solar cell efficiency using theoreically ideal materials is 33.7% - so the range is now 28 MW/km² for nominal cells in my area to 90.99 MW/km² for platonic ideal solar cells (which don't yet exist) in the sunniest place on earth.

Additionally, solar farms aren't typically a solid block of panels; there's access roads for maintenance, and they typically occupy about 25% of the land. So we're down to 21-68 MW/km².

He talks like he's has some kind of analysis done, but clearly, he has not. I mean, this isn't even confusing nameplate capacity with generation - he'd only get 115-365 MW/km².

In the most generous case, the maximum _theoretical_ land generation density for solar PV is 1.5% that of typical nuclear. Elon is just _wrong_ here.

An enterprising greenwasher could fill a nuke plant's exclusion zone with solar panels. You wouldn't get much for your money, strictly speaking, but the reaction from the archaeogreens might be interesting at least.

Now, It could be the case that Elon Musk doesn't know that insolation is not generation, or didn't know about SQ - and usually I prefer to assume incompetence over malice - but this is Elon freaking Musk here. The man's an engineer first, and is _in the solar business_. If he doesn't know the limitations of his own investments, I have literally no idea how he's successful.

It's likely that he's selecting his words carefully so as to avoid outright lying, while intentionally misleading people into believing that solar is more land-dense than nuclear.

Thing is, he's got the cash and brains (not just his, but access to others) to be a new leader in American nuclear, and with the new grants for nuclear research, I can see it being a potentially attractive prospect for him. Not just that, but his name alone brings green cred and trust that nuclear inexplicably lacks. With just a modicum of vision, he could be on top of a trillion dollar game, end fossil fuels for good, and lead the charge against climate change - but instead he's sitting there intentionally misrepresenting things - I can only imagine, to boost his solar business.

Nothing disappoints me more than the Tony Stark of the real world being this thick.

[TCBYEAHCUZ]

This is the only thing i disagree with elon on. To think that solar power can reliably generate more energy in the amout of space a nuclear plant uses than the nuclear powerplant itself is preposterous. Baseload capacity factor of nuclear=95%, Solar? you're lucky if you reach a capacity factor of 30%

[solortus]

Lol notice how he didn't cite how much energy nuclear produces. He's smart enough to know nuclear out performs solar but doesn't want to state it because of his business interests

[silentstealth]

Could you put solar panels in the clear area around a nuclear plant?

[RuthwikRao]

Don't really think I can agree with him here. Even intuitively speaking, he comes off as dishonest on the solar output relative to land size of nuclear plants.

Even Tony Stark is fallible.

[sabinareefing]

That's some bad math....ivanpah (new solar plant in idea location) is 14 sq Km and has a 377Mw capacity. That equals 27Mw per Km NOT 1000Mw.... He's wrong by a factor of 50x.

[samscott]

Last time I checked, Solar Energy (The Sun) is fueled by nuclear reactions.

[nickman]

To anyone who thinks nuclear is bad or atleast not as good as wind and solar.
Have you read any of the science on the mortality rate of different energy sources per unit of energy generated? The studies I have read have said that even counting those two melt downs. All of the deaths from nuclear energy are less than the deaths of solar energy or any other energy source for that matter. Also take into account that Nuclear has generated 30-100 times more energy than solar. Lastly Nuclear has less of a CO2 footprint than any other energy source, including Wind and Solar (Yes, they have a CO2 footprint in their construction.) If you hate nuclear waste than you will hate solar waste even more, solar panels last at most 25-35 years right now. The waste from solar takes up far more space and contains very toxic materials, that unlike nuclear do not become safe with time. Their is no reputable scientific study that says that Solar or wind is safer, more efficient, or more environmentally friendly than nuclear. If you find one post it. I advise you to at least check out this scientific study at some point. Source: Renewable and nuclear electricity: Comparison of environmental impacts (Author Michael Jefferson)

[jer]

Don't think he's accounting for the amount of energy we can actually extract though. Yes, the sun would provide that much energy to a square km, but solar panels can only extract ~20% of that. Then there is the giant problem where the sun goes away, some call this nighttime. Requiring some type of long-term storage (batteries? super capacitors? *new thing*?). Not saying it couldn't be done, but I think he's being purposefully misleading to prop up solar.

How bout a nuclear plant where the unused space has solar panels. Hell, put solar panels on top of the reactor building for all I care!

[lukehp]

i swear i love you elon (i even have a Tesla mug), but i have to disagree with you on this one...

[LFTRnow]

There is 1 GW of solar energy at PEAK in the summer in a sq. km, assuming you can extract it all. There is space between the collecting panels, losses, etc. Nuclear produces power 95%+ of the time, solar is closer to 10%. If you really want to compare solar to nuclear, while ignoring the energy storage issue, the problem of getting the power to the consumer, etc and just look at energy produced, compare the ENERGY (ie GWh) not the peak output.

[nafiulshelim]

The clear area can be for wildlife. Why does every land have to be developed on.

[YORKscooterCLUB]

I can't even be bothered to write a lengthy reply to this instead I'll just present my stupidest thing I've heard all day award. Someone send him a calculator.

[philspaghet]

I so disagree with Elon about this. Sure Solar is theoretically infinitely renewable but Nuclear has an energy density significantly higher than even traditional power plants. Not to mention the effort needed to maintain the area of solar panels Elon is talking about.

[BeckOfficial]

Sooo... fill the clear area with solar panels and get energy for years. Easy!

[leerman]

Why is he confusing people with nameplate capacity and real "energy" produced? It's only doing that 14% of the time where I live, plus solar panels are 14-20% efficient at converting that "power". You would need 34 times as much area as Bruce nuclear to make just as much "energy" a year.

[jmmacalalag]

He's partial owner of solar company so he has to say this but I think he knows nuclear is better... You would have to clear all that land space first which isn't environmently friendly, producing and decommission of panels causes alot of pollution.

[Paultimate]

I like Elon, but he is 100% wrong here. I understand youre trying to push Solar, Elon, but LFTR is literally hundreds of times more space efficient and efficient in power put in-> power output ratios. Solar has limited uses and it excels greatly at those use cases but it is NOT for heavy lifting.


We need to promote LFTR, not just any Nuclear technology. L F T R. This would literally change our entire civilization for the better in massive ways if we get this shit going. We have spent decades with it fucking sitting around. Imagine if they stopped right after creating the first integrated circuit. This is BIGGER than even that.

[mrkokolore]

I don't know why Elon Musk thinks that nuclear power plants need a lot of space. The nuclear power plant Brokdorf in Germany, for example, covers about 300, 000 m² and produces about 1.4 GW of electricity. I don't know what solar panels he means but at a cloudy day one m² of solar only produces about 100 W. Only at the perfect time, weather and angle it could theoretically produce 1000 W. So Elon Musk takes this perfect circumstances for granted when he says 1 km² produces 1 GW.

[richhenry]

The sun doesn't shine all day every day Elon.