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Solar energy solves global warming

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Re: Solar energy solves global warming

#71

Post by pfdietz »

mirko22 wrote: post #55
pfdietz wrote: post #45

Earlier quoted context omitted.

What do you mean by "efficient"? Engineering efficiency? They use different inputs, so comparing that is meaningless. Economic efficiency? No, they're much less economically efficient. That's why so much more solar (and wind) are being installed now instead of nuclear.

I doubt that somehow, reason we are pushing wind and solar is cos people think it is “green” and “renewable” and are scared of nuclear. Take example of Germany where they shut down the nuclear power plants just cos of popular pressure…

> I doubt that somehow, reason we are pushing wind and solar is cos people think it is “green” and “renewable” and are scared of nuclear.

This is utter nonsense. The reason wind and solar are being pushed is they are so much cheaper than nuclear (and this will remain true even at high renewable uptake when storage is required). This is widely understood; where did you get the bizarre incorrect belief that it was otherwise?

Nuclear was so out of the running in the US that many existing NPPs had to be shut down because they were cash flow negative. It wasn't worth running them even with the construction and financing costs completely written off. The remaining reactor at Three Mile Island, for example, had not made an operating profit for six years before it was shut down.

Re: Solar energy solves global warming

#73

Post by tastyfreeze »

Nice! Synthesizing fuel is something I think about whenever I study power generation. Ideally, the synthesized fuel doesn't require cryogenic storage to store large quantities. The less energy that storage requires the better for fuel ubiquity. I dream of a fuel generating device that is utilized to dump excess generated power. Currently off grid power generation dumps load as heat. The heat is often used to heat water or a room but occasionally dumped in atmosphere.

Methane synthesis is the first step in a whole chain of high energy synthesis. The two most important economically are longer hydrocarbons (ethane, propane) and ethylene which is the base for poly-ethylene plastics.

But, for synthesis the electricity has to be essentially free to be economical. These chemical pathways require a lot of energy. I would probably use methanogens to create methane from organic waste then use excess electricity for higher order synthesis.

Re: Solar energy solves global warming

#74

Post by AlanSE »

hannob wrote: post #17

When considering synthetic chemicals made from solar energy, methane is probably one of the last you should consider. Making any type of chemical energy carrier comes with substantial losses, so whenever you can, using electricity directly is better. If you absolutely need a chemical energy carrier, the first one you will look at is hydrogen, because it's the simplest and you avoid all the direct air capture or other…

I've been following Terraform Industries for a while, and it does strike me as obvious that H2 will be the preferred form of energy storage medium in the long run, not just an intermediate species.

Depending on the conditions, if you're doing day-night energy storage, then you would like to fill up the H2 tank and then burn it when demand ramps up.

The only role I see for methane is when your H2 tank is already filled up but your solar panels are still producing. This is not just possible, but deterministically required whenever solar gets deployed enough for seasonal storage to be necessary.

Right now California is something like 35% solar + wind energy, and the "duck curve" is nearly maxing out. This was predicted in extreme specificity 20 years ago, as >30% and you get stuff like zeroed-out energy prices during the day. We have not solved the day-night (daily) energy storage problem, which only requires storing energy for a matter of hours.

When you go to something like 60% renewables, then even crazier stuff happens. Overproduction during sunny times goes bananas and (assuming daily storage is solved, which it isn't) seasonal issues start to arise. I don't think H2 will ever work for seasonal storage, although I think it's fine for multi-day storage scenarios. It's not theoretically impossible, I just compare to the equivalent that we have for natural gas and realize you would need MANY TIMES that level of investment to save the same amount of energy in H2. Plus, fossil fuel gas producers are mostly at a constant level, whereas solar production outright needs summer-to-winter storage.

What I don't buy is that these units will be disconnected from the grid and be economical by their gas products. No way, no how. What you want is to run the chemicals plant with low-voltage solar power locally, and trade-off with the grid as is economical.

Re: Solar energy solves global warming

#75

Post by narag »

slashdev wrote: post #51
narag wrote: post #49

Earlier quoted context omitted.

Making any type of chemical energy carrier comes with substantial losses The goal presented in the article seems to be cleaning the atmosphere, not generating chemicals. So H2 and ammonia would be irrelevant. And it's not so much about maximazing efficiency as not losing too much. The alternative should be other carbon-based chemicals, as useful as methane, needed in huge volumes and with a practical process of extra…

That’s nonsensical, because you burn the methane and put the carbon right back into the atmosphere. It didn’t clean anything. It’s merely a carbon neutral form of chemical energy. H2, ammonia, methanol would be just as carbon neutral.

Well, it's there in the title of the article, so don't shoot me. If the premise of the article is bs, it doesn't make sense to discuss efficiency.

Is it nonsensical though? IDK, it seems somehow better than extracting the gas from the ground and adding it to the system. Also if there's another more complex chemical not for burning, that you can synthesize from the methane, it would be a net gain.

Re: Solar energy solves global warming

#76

Post by kibwen »

NickM wrote: post #43
kibwen wrote: post #34

Earlier quoted context omitted.

There was just as much sunk cost into coal infrastructure, but that's not an argument against phasing out coal.

Sure, but if we could reuse the coal infrastructure as part of a transition away from fossil fuels, why wouldn't we consider that? Unlike methane, coal is mostly just used for power generation, and there's relatively little infrastructure associated with transporting it. Natural gas is used for furnaces, stoves, dryers, hot water heaters, etc. and there are millions of miles of pipes and associated infrastructure use…

> The complexity and cost for retrofitting hundreds of millions of homes and electrifying all the associated appliances is immense

This is overselling the difficulty. What you're saying is true, but you don't need to rip out functioning appliances. Appliances have a finite service lifetime; once they fail, replace them with electrified appliances. Already here in the year 2023, I wouldn't dream of building a house with a gas stove or gas heating. Induction stoves are just plain better than gas stoves, and heat pumps are cheaper than gas heating once you factor in that the gas-heated house will need a separate AC installation for cooling, whereas the heat-pump house won't. These days, methane doesn't make sense anywhere except at the power generation end, and power generation sources are fungible and can be gradually replaced on their own schedule.

Re: Solar energy solves global warming

#77

Post by hannob »

NickM wrote: post #53
hannob wrote: post #17

When considering synthetic chemicals made from solar energy, methane is probably one of the last you should consider. Making any type of chemical energy carrier comes with substantial losses, so whenever you can, using electricity directly is better. If you absolutely need a chemical energy carrier, the first one you will look at is hydrogen, because it's the simplest and you avoid all the direct air capture or other…

the first one you will look at is hydrogen, because it's the simplest Simplest chemically != simplest to use in practice. There are already millions of miles of natural gas pipelines leading directly to peoples' homes, and those pipelines cannot be used with hydrogen (not to mention all the appliances they feed). Renewable methane is a dead simple drop-in replacement for natural gas. None of the other alternatives yo…

None of these chemicals will be used in people's homes in any meaningful quantity. That's just not going to happen due to the conersion inefficiencies.

Re: Solar energy solves global warming

#78

Post by hannob »

msandford wrote: post #23
hannob wrote: post #17

When considering synthetic chemicals made from solar energy, methane is probably one of the last you should consider. Making any type of chemical energy carrier comes with substantial losses, so whenever you can, using electricity directly is better. If you absolutely need a chemical energy carrier, the first one you will look at is hydrogen, because it's the simplest and you avoid all the direct air capture or other…

Failing to understand the enormous amount of methane infrastructure (natural gas) and the utility of reusing it is also a mistake IMO. There's got to be tens of trillions of dollars in deployed methane infrastructure. To suggest that's a weak argument is baffling. Economics are real.

The thing is: Most of that infrastructure is obsolete in any case.

These synthetic chemicals will play a role in industry and shipping, probably also in long-duration storage. But they won't be in widespread use like fossil gas today. They're just too inefficient.

Re: Solar energy solves global warming

#79

Post by kibwen »

BobbyJo wrote: post #60
kibwen wrote: post #34

Earlier quoted context omitted.

There was just as much sunk cost into coal infrastructure, but that's not an argument against phasing out coal.

Not really. The reason coal was so popular was because you didn't really need any specialized infrastructure. It is a solid you can just ship using the same trains and trucks you use for TVs and apples. So you're really only giving up the mines and power plants.

This seems to be arguing that the existence of natural gas pipe infrastructure is somehow a benefit of natural gas, rather than a downside. The pipes are an expense, to say nothing of the fact that even our best-maintained pipes are leaking 2% of their gas directly into the atmosphere per year (the worst are leaking double or triple that). A hunk of coal that falls off a truck doesn't contribute to emissions; a leaky methane pipe does, which can actually make natgas plants overall worse for emissions than coal.

Re: Solar energy solves global warming

#80

Post by ianburrell »

pfdietz wrote: post #46
photochemsyn wrote: post #29

If you're going to try to use solar power to reduce the concentration of CO2 in the atmosphere, the only endpoints that make much sense are carbon fiber and diamond. Things like limestone require a counterion like calcium or magnesium for each captured carbon atom, which is hard to come by. Routes to carbon fiber and diamond pass through methane, which is also the input for the vast majority of petrochemical processe…

Counterions like magnesium are quite abundant. After all, this is how CO2 will be drawn down if we do nothing (but it will take hundreds of thousands of years.) There has been much work on exploiting the more reactive silicates, like olivine, to fix CO2. The volumes of rock involved are large, but there's a lot of silicates out there.

Weathering rocks to absorb carbon makes a lot of sense. It doesn't require any new technology. The equipment can be powered by electricity and only run when there is excess power available. It should scale well, but does need large scale to make a difference.
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