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Fusion reactors: Not what they’re cracked up to be

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Re: Fusion reactors: Not what they’re cracked up to be

#191
post #126
post #114

Earlier quoted context omitted.

On the plus side, the CO2 from burning natural gas is less than coal and it doesn't emit mercury or the other particulates and doesn't have a waste issue like coal does. Unfortunately for those who care about climate change, (and if you don't, you should) there are inevitable methane releases from fracking and from distribution of natural gas and those are now known to be much worse than previously thought: >...Back…

100,000 tons of methane with a half life of less than 10 years. The math is complex and 1 ton of methane becomes more than one ton of CO2, but the actual long term impact is fairly minimal vs the savings from not using Coal. Remember that's ~100,000 tons / ~10,000,000,000 tons = 1/100,000 so yea methane is bad, but in this context it's 0.001% so it's still a rounding error even if it's 100 times that bad. Anyway, I a…

>100,000 tons of methane with a half life of less than 10 years. The math is complex and 1 ton of methane becomes more than one ton of CO2,

You are downplaying the impact of methane. As I quoted in the last post, the IPCC estimate is that over 100 years a given amount of methane is 34 times more potent as a heat-trapping gas compared to CO2. Over a 20 year period (which is probably more relevant considering where we are in climate change) methane is 86 times more potent.

>...but the actual long term impact is fairly minimal vs the savings from not using Coal.

That's the problem - there is enough methane being released by our new reliance on natural gas there is concern that we may be having just as much of an impact on climate change as if we went and burned coal.

>...Remember that's ~100,000 tons / ~10,000,000,000 tons = 1/100,000 so yea methane is bad, but in this context it's 0.001% so it's still a rounding error even if it's 100 times that bad.

The problem is that EVERY natural gas well, storage facility and pipeline leaks methane. This was just the largest one. As I quoted in the last post, "...Back in August, a NOAA-led study measured a stunning 6% to 12% methane leakage over one of the country’s largest gas fields — which would gut the climate benefits of switching from coal to gas."

>... But, if we got to the point where peaking power from gas makes up ~10% of total electricity supply and the rest of that is renewable power then we will have made massive progress.

Yea no kidding - 90% power from intermittent sources would be pretty remarkable. The problem is that 90% power from intermittent sources won't be possible unless there are major advances in grid storage technologies.

In terms of having to use natural gas, nuclear power plants in France and in Germany operate in load-following mode, so there is no reason this can't be done elsewhere. Minimizing our use of natural gas when when you consider the climate changing negative externalities of natural gas, would be a good thing.

Re: Fusion reactors: Not what they’re cracked up to be

#193

Earlier quoted context omitted.

The ocean environment isn't easy on equipment, plus storms are a major issue. Then there's cabling...

That all looks trivial compared to the challenges of fusion power, though.

By the time you mount those panels on a floating structure the lifetime energy yield may well drop to zero or (most probably) negative. Building a ship has a huge energy/emissions cost as the raw materials have to be mined, refined, transported, formed and assembled.

I'd recommend this site for a good overview on where our energy really goes and what might be achievable with renewables: https://www.withouthotair.com/

Re: Fusion reactors: Not what they’re cracked up to be

#194
post #191
post #126

Earlier quoted context omitted.

100,000 tons of methane with a half life of less than 10 years. The math is complex and 1 ton of methane becomes more than one ton of CO2, but the actual long term impact is fairly minimal vs the savings from not using Coal. Remember that's ~100,000 tons / ~10,000,000,000 tons = 1/100,000 so yea methane is bad, but in this context it's 0.001% so it's still a rounding error even if it's 100 times that bad. Anyway, I a…

>100,000 tons of methane with a half life of less than 10 years. The math is complex and 1 ton of methane becomes more than one ton of CO2, You are downplaying the impact of methane. As I quoted in the last post, the IPCC estimate is that over 100 years a given amount of methane is 34 times more potent as a heat-trapping gas compared to CO2. Over a 20 year period (which is probably more relevant considering where we…

That's just lying with numbers. 86 / 5 = 17.5 so average from year 20 to year 100 is 34 - 17.5 = 16.5x. And again the majority of that 16.5 is over years 20-40.

Further, because of this decay increases in release rate don't stack at 86x year over year. You get a magnified increase in the first year and a smaller net increase every year after that until your down to the carbon content of methane.

Under 10% total gen from peaking power is viable with over production of wind and solar and zero grid storage. It's not going to be 10% 24/7 but 0 most of the day, regular generation at part of the day, and rare spikes up to 50%. You can drop that under 5% with moderate grid storage of around 1h average demand, but you start needing vastly more storage the lower you want to take that number.

Re: Fusion reactors: Not what they’re cracked up to be

#195

Earlier quoted context omitted.

You can do things with the excess power that otherwise would be un-economical to do during a cloudy day. Things like smelting aluminum, desalinating water, etc take massive amounts of power.

You can't just do those things when the weather is good. Not without huge tax breaks to incentivise load following, because intermittent production of large scale industrial processes is hard and not cheap.

They already do this without any gov intervention. The local steel recycling plant only operates when power is cheap. While they do need some advance notice to make sure they have enough people to run, they probably can get a good enough idea from a weather forecast (power here is mostly hydro with a dollop of wind and fossil).

Some processes are better fits than others. If you have 2-5x extra capacity that is sold cheap on sunny days, someone will figure out how to use it.

Re: Fusion reactors: Not what they’re cracked up to be

#196

Earlier quoted context omitted.

Sorry I worded that sentence poorly. Let's assume two scenarios: a) We create a 200 square mile solar field in the Sahara, from which cables run to Europe to supply electricity. To take this plant out, one just cuts the cables. There, you just plunged Europe into darkness. b) We create a 20x 10 square mile solar fields in the Sahara, all dispersed over a very large area. Well, this is an engineering and construction…

I'm surprised to see this kind of simplistic reductionist thinking on HN. "Just cut the cables" isn't trivial. Have you ever seen a high voltage tower? Not only are they not accessible without professional gear, it's also going to require even more expensive gear to cut multiple inch thick conductors. In all likelihood he power to Europe will be transmitted via multiple undersea cables, the effort of disrupting which…

Then "evil state" bombs cables, or power plant. The point is that the cost of defending such a crucial part of our infrastructure would not be trivial, and it's still hosted on foreign soil, so... politics.

Re: Fusion reactors: Not what they’re cracked up to be

#197

Earlier quoted context omitted.

A large solar field makes for a pretty diffuse target. You might be able to target the connection to the grid, but that's no worse than it is today (and would be easily repaired). And I don't think our current electrical grid has a major problem that even a slight attention to infrastructure couldn't fix.

Ok so you are saying that the new solution isn't any worse in terms of security than the current one, so it's fine? In any case, you cannot compare this to oil pipelines directly because we can stockpile oil. Even if all the pipelines are taken out, many countries stockpile oil that can bridge them over until an alternative solution is found. If a considerable part of the electricity comes from some remote site in a…

"Ok so you are saying that the new solution isn't any worse in terms of security than the current one, so it's fine?"

Yes. You're blowing up the security argument when really it isn't the security of it that is the problem -- our current infrastructure isn't more secure, and we have had only minimal problems with it thus far. The problem is the imminent and looming destruction of various thousands of ecosystems, and the continuing habitability of the planet.

It could be done. We got to the moon in about twenty years, which was much more of a technological leap than this will be. With the concentrated effort and enough propaganda, we could make the switch from coal/gas/oil. We are very rapidly running out of runway.

Re: Fusion reactors: Not what they’re cracked up to be

#198

Earlier quoted context omitted.

Absolutely. The infrastructure is very fickle, but also enormous on the scale of countries. Since we're talking about hypotheticals, I could say these things are also true: 1. There are counter-drones deployed and patrolling air space above the towers. 2. There are hundreds of independent power lines with 2N redundancy, so cutting 5-10 high voltage lines would do nothing. 3. The undersea cable points are protected by…

I don't think the main problem here is random terrorists cutting power to Europe by blowing up a power line tower. The real problem is that nation states that control the Sahara haven't proven to be stable (Syria, Egypt), or don't always have great relationships with Europe (Algeria in the 90s). As to points 4 and 5, although storage and some backup capacity is reasonably feasible, this would mean that Europe could v…

(I obviously meant Libya, not Syria)

Re: Fusion reactors: Not what they’re cracked up to be

#199
post #103
post #91

Earlier quoted context omitted.

The term Baseload power is not a goal, it's a Problem with some types of power not being flexible. In that context, soar is closer to Baseload power than peaking power plants. Yes, it currently better matches demand than Baseload power, but as you ramp it up the supply / demand miss mach will simply shift around the day. Turning on some peaking power plants at night vs the day is not a significant issue. Further, the…

You are handwaving away huge issues here. As Bill Gates said in the same interview I quoted from before: >"...It’s kind of ironic: Germany, by installing so much rooftop solar, has it that both their coal plants and their rooftop solar are available in the summer, and the price of power during the day actually goes negative—they pay people to take it. Then at night the only source is the coal, and because the energy…

Bill Gates is very much part of the problem.

Having fossil fuel plants that only operate when needed, but get paid more per kWh than they do now when they run all the time (since as well as fuel costs they have up front construction to cover) is not even close to being a problem. It is in fact part of the solution. What is he doing complaining about this?

Negative prices are also not the big drama he makes them out to be. Sad that he's got a reputation as some kind of genius and he's scared of negative numbers as if it's some kind of witchcraft to have too much of something and use pricing and markets to decide which providers should scale back.

Translating for those scared of negative prices: someone wants to keep providing power for some reason (maybe their setup doesn't like rapid changes in output, which would cost them money in repairs), they want to pay you $X to shut down your system instead. Do a calculation and figure out if shutting down your system is cheaper than that, if so, take the money. Market forces at work! The inflexible system don't make as much money, and the flexible systems gain it.

Or, someone with flexibility in when they need electricity says "I'll agree to heat my water tanks at the point that helps the grid most, how much will you pay me for doing that? The amount we'll pay you is the negative price, except not negative anymore".

Re: Fusion reactors: Not what they’re cracked up to be

#200

Earlier quoted context omitted.

Desalination of seawater seems a safe bet for excess solar power.

That's a horrible solution. Water is even less portable than energy, even the driest desert can't afford to import water. You're trading a highly liquid but hard to transport commodity for a highly illiquid and hard to transport commodity.

Scenario 1: Your solar power is used near the site of the power installation. In this case, there must be people living near the site in order to use all that power. Those people require freshwater. Therefore, there will be a means to transport water to the site.

Scenario 2: Your solar power is used elsewhere. In this case, there must be a means to transmit power to the people who will use it. Those people are likely to live near seawater. The closest such people are also likely to have a limited supply of freshwater.

You are already either transporting water to the solar site, or transporting power away from it to somewhere else. So the idle capacity of the solar plant will be usable for desalination and/or wastewater reclamation. And I think aqueducts, particularly seawater aqueducts, are cheaper than you realize. The majority of energy required is in increasing the elevation of the water, and that can be done with surplus power, too.

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