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Why is nuclear fusion so hard?

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Re: Why is nuclear fusion so hard?

#51

Post by eloff »

martythemaniak wrote: post #45
thoughtstheseus wrote: post #42

Earlier quoted context omitted.

Regarding solar placement, we can place panels on housing and commercial buildings and parking spaces. Check out canopy style parking covers(sun protection)in the southern US.

I once did my own calculation to answer the question: "How much land do you have to cover with solar panels to meet Toronto's electricity needs". The answer: about 3.5x the size of the city. Covering every square inch of the city is not sufficient, you need a lot more land. You can double-check my calculations: take the output of largest solar farm installations, note their land area, adjust for solar radiation at yo…

At Canadian solar intensity levels? I'd be surprised if it's only 3.5x. You can't count on average intensity for the year either, you really need to look at the lowest intensity and go with that number. You can use battery storage, but you are not going to be storing electricity from the summer for the winter.

Anyway even at 10x, Canada has a LOT of land, that's totally viable and wouldn't even make a dent in land-use compared to say agriculture.

Re: Why is nuclear fusion so hard?

#52

Post by mdavis6890 »

vegetablepotpie wrote: post #47
candiodari wrote: post #38

Earlier quoted context omitted.

Yeah this is something people keep forgetting. The reason fossil fuels have such an impact is because the industry is happening at such a scale. Solar and wind are working at miniscule size ... and ... "no" impact (well, wind clearly has impact already, but ... let's forget that). Well actually, solar does have an impact. In Spain there's a couple large wind farms I visited and ... not that it should surprise anyone…

I think Fission would be great if we had somewhere to put the waste, if it didn't cost $10 billion dollars to set up a plant and people weren't phobic of it. Overall Nuclear makes more sense than coal and arguably more sense than wind and solar. But then there's the risk of the meltdown. No politician, no utility CEO, no corporation commission is going to take the risk of a meltdown when the political cost of pumping…

Your point about political risk is very valid, but your points about the waste and cost need to be reconsidered. A big part of the cost is artificial, not inherent: regulation. A person may or may not think the regulations are a good thing, but it's not an inherent cost. The waste is not much problem. The amount of waste to power the lives of a whole family for their entire lives would easily fit in a shoebox and be easily contained in water. And most of that radioactivity dissipates very quickly.

Re: Why is nuclear fusion so hard?

#53

Post by kamaal »

mikeash wrote: post #46
mannykannot wrote: post #41

This is somewhat tangential to the specific issue here, but I was surprised by this: At the center of the Sun, fusion power is estimated by models to be about 276.5 watts/m3. Despite its intense temperature, the peak power generating density of the core overall is similar to an active compost heap, and is lower than the power density produced by the metabolism of an adult human.[1] So practical fusion power requires…

That also shows why fusion power always centers around exotic isotopes like deuterium and tritium rather than plain hydrogen. The reaction paths needed to fuse plain hydrogen are so improbable that they don’t happen fast enough to be useful.

Is this an another way of saying that the only way to fuse to Hydrogen is to create a structure as large and with gravitational features that of a star?

Then a star/solar energy is the only way you will ever have large scale fusion energy generation and harvesting.

Re: Why is nuclear fusion so hard?

#54

Post by DennisP »

Retric wrote: post #26
DennisP wrote: post #21

Earlier quoted context omitted.

Unless you have a very cheap and very scalable storage solution, that would be a mistake. France took their grid from zero nuclear to 80% nuclear in two decades. We don't have a comparable example for wind/solar.

That’s a function of how recently solar and wind became cheap. China has a 31x increase in wind power over the last 10 years. The next 10 will be very interesting assuming prices continue to fall. When having a 30% oversupply of wind / solar still costs less than any alternative and they are only gettting cheaper eventually noting else comes close.

It's also a function of not yet having really cheap, scalable storage that's not limited by geography.

In any case, it's clear that nuclear can do the job if we're smart about it, because France did it.

Re: Why is nuclear fusion so hard?

#55

Post by pitaj »

mdavis6890 wrote: post #52
vegetablepotpie wrote: post #47

Earlier quoted context omitted.

I think Fission would be great if we had somewhere to put the waste, if it didn't cost $10 billion dollars to set up a plant and people weren't phobic of it. Overall Nuclear makes more sense than coal and arguably more sense than wind and solar. But then there's the risk of the meltdown. No politician, no utility CEO, no corporation commission is going to take the risk of a meltdown when the political cost of pumping…

Your point about political risk is very valid, but your points about the waste and cost need to be reconsidered. A big part of the cost is artificial, not inherent: regulation. A person may or may not think the regulations are a good thing, but it's not an inherent cost. The waste is not much problem. The amount of waste to power the lives of a whole family for their entire lives would easily fit in a shoebox and be…

Don't forget to mention that old waste can even be consumed in modern reactors.

Re: Why is nuclear fusion so hard?

#56

Post by TheOtherHobbes »

martythemaniak wrote: post #45
thoughtstheseus wrote: post #42

Earlier quoted context omitted.

Regarding solar placement, we can place panels on housing and commercial buildings and parking spaces. Check out canopy style parking covers(sun protection)in the southern US.

I once did my own calculation to answer the question: "How much land do you have to cover with solar panels to meet Toronto's electricity needs". The answer: about 3.5x the size of the city. Covering every square inch of the city is not sufficient, you need a lot more land. You can double-check my calculations: take the output of largest solar farm installations, note their land area, adjust for solar radiation at yo…

No one has ever suggested that renewables = solar.

Renewables are always a mix of solar, wind, hydro, and - eventually - wave.

Re: Why is nuclear fusion so hard?

#58

Post by mdavis6890 »

hwillis wrote: post #44
FlyMoreRockets wrote: post #31

Earlier quoted context omitted.

I used to be a reactor operator and never saw any evidence they were hard to throttle. That's why they are used for warship propulsion: loads in battle are not predictable by their nature, what with changes in course, catapult launches, etc.

You're both right- technically, nuclear reactors are on of the fastest-ramping sources available. A reactor in SCRAM can drop down to However, zero reactors are capable of doing so economically. The cost of a nuclear plant is in its construction, upkeep, and staff. Those costs are the same at 110% and 30% output, but revenue isnt. In order to turn a profit a nuclear plant needs to be running at 80%+, 24/7. Ultimately…

There is a flaw in your reasoning: By definition if a plant needs to be throttled then it's surplus power generation has negative (or zero) utility/value and therefore does not contribute to it's profitability whether it's running or not. Throttling the plant doesn't reduce it's profitability, since the power it would product at that point has no value - that's why you need to throttle it.

Re: Why is nuclear fusion so hard?

#59

Post by randallsquared »

TheOtherHobbes wrote: post #49
candiodari wrote: post #38

Earlier quoted context omitted.

Yeah this is something people keep forgetting. The reason fossil fuels have such an impact is because the industry is happening at such a scale. Solar and wind are working at miniscule size ... and ... "no" impact (well, wind clearly has impact already, but ... let's forget that). Well actually, solar does have an impact. In Spain there's a couple large wind farms I visited and ... not that it should surprise anyone…

Your facts appear incorrect. Renewables consistently produce more than 60% of Portugal's energy needs, and have topped 100% on occasion. The figure for Spain is more than 35%, and more than 35% of electricity consumption in Germany. I'm not sure how you get from 60% to "no impact". It's really quite a puzzling statement. As is the suggestion that windfarms cause some kind of ecological blight to farmland. Not only is…

The GP's post had "below the panels" in the description of the "wind farm", which was preceded by "actually, solar does have an impact". Surely the charitable explanation is that "wind" was just a mistake?

Re: Why is nuclear fusion so hard?

#60

Post by eloff »

kingkongjaffa wrote: post #50
kjar wrote: post #3

For most of my life fusion has been teased but not delivered. fission has been pimped for decades yet cannot get private funding, or build reactors in a decade, or provide solutions for the waste. Yet still the industries persist with their propaganda while renewables beat them in cost and time to operation. If I managed the funds I'd cut nuclear and redirect to wind and solar immediately.

Wow this is an insane view point, I actually thought you were going to suggest the opposite... Frankly the potential capability of nuclear far outweighs anything else. If the gen public were more on board with it, nuclear could be rolled out and be the main source of power in the world in 30-40 years, removing the need for fossil fuels for power generation. Even building them in remote locations and taking the transm…

The economics aren't there. Solar and wind are well below the costs of nuclear and still dropping fast. Costs of energy storage are dropping fast as well. I think the window has closed on nuclear for the time being. Thinking as an investor it's too risky and too expensive to produce the same fungible commodity as a solar cell + battery.

We're fast getting to the point where wind and solar is going to wipe out fossil fuel generation - for new construction - in some places it already has. Never mind nuclear, nuclear just isn't in the game anymore.

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