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Solar energy solves global warming

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Re: Solar energy solves global warming

#101

Post by pfdietz »

AlanSE wrote: post #74
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 fille…

California has 5 GW of grid batteries (I think that's 20 GWh of storage).

The peak demand today at CASIO is around 36 GW (interestingly, ERCOT's peak is much higher. Texas should invest in efficiency.)

The "duck curve" looks like it's already partially ameliorated by batteries, and not that much battery capacity will be needed to smooth it out entirely.

Re: Solar energy solves global warming

#102

Post by pfdietz »

mirko22 wrote: post #52
iSnow wrote: post #26

Earlier quoted context omitted.

The problem with nuclear is that there is no cheap form factor of nuclear reactors available right here and now, it's all "in the future...". Current NPP designs have painfully high CAPEX, way more so than solar. And just slashing regulatory requirements to make it cheaper strikes me as unwise.

Well the solar stuff is in the future too :)

The solar stuff that's "in the future" can be estimated by extending the historical experience curve for PV. Doing that, solar delivers at below $0.01/kWh by the time it's fully rolled out.

Do you think people with money want to invest in nuclear power plants with that economic Sword of Damocles hanging over the technology?

Re: Solar energy solves global warming

#103

Post by pfdietz »

ianburrell wrote: post #80
pfdietz wrote: post #46

Earlier quoted context omitted.

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.

It also can make sense to add limestone (or other carbonates) to the ocean. As long as you don't make the ocean too alkaline, you get the following net reaction:

CaCO3 + CO2 + H2O --> Ca(+2) + 2 HCO3(-1)

Re: Solar energy solves global warming

#104

Post by pfdietz »

ZeroGravitas wrote: post #11
V__ wrote: post #4

> In the future, we will still have CO2 credits. But instead of allowing companies to release CO2 into the air… Credits might allow companies to capture co2. The article then goes on to explain that solar + co2 capture results in methane. But isn't this at best co2 neutral? Since nearly all use-cases for methane would release the co2 again and would make the credits' comparison pointless? Besides that, will methane a…

I think they mention it further down, but some fraction of methane isn't burned but turned into things like plastic and other industrial chemicals. > And not all of it will be re-released into the atmosphere. As we saw in the Ocean Farming article, some of it will sink in the oceans13 . Even today, 3% of methane is not burned, but used in other ways like plastics production, thus leaving the carbon cycle altogether..…

3% of Natural Gas, not methane. Natural gas contains other gases, in particular ethane, which is the feedstock for making ethylene and then polyethylene.

US fracked gas is quite high in ethane.

Some of the natural gas used for plastics is to make heat, for example to drive ethylene crackers (which decompose ethane at high temperature). Methane could be burned for that.

There was a process for oxidative coupling of methane to make ethylene (a Bay Area startup named Siluria created it, using a cool phage-based combinatorial method to find structured catalysts) but I don't think it could compete with all that cheap natural ethane.

Re: Solar energy solves global warming

#105

Post by rich_sasha »

foxyv wrote: post #96
hannob wrote: post #48

Earlier quoted context omitted.

> Methanol production requires methane as a synthesis gas so it just adds another step. That's not true. Methanol can be made directly from CO2 and H2. This has been tried more than a decade ago: https://www.carbonrecycling.is/ They just opened a much larger plant with this technology in China. There's currently a huge push in the shipping industry towards renewable methanol, and there are a bunch of companies invest…

E-Methanol is okay as a carbon neutral fuel and solvent. At 50-60% efficiency it makes an excellent fuel to create from electricity. But it is still a long way from competing with battery and pumped hydro. It's fuel cell efficiency is only 30% with current technology after the 40-50% losses from the creating of the fuel itself. You can buy a lot of transmission wire at that price point. All of these technologies illu…

But I guess you can make a lot of methanol in summer and burn it in winter, storing it cheaply for months. Batteries so far seem maybe ok at balancing diurnal power generation / use patterns but not seasonal storage.

Re: Solar energy solves global warming

#106

Post by _hypx »

foxyv wrote: post #100
pfdietz wrote: post #39

Earlier quoted context omitted.

For static applications, hydrogen can be easily stored underground. Energy is used to compress it, but that energy can be recovered by running it through an expander (and if the compression/expansion is done in stages to approximate isothermal compression, the round trip efficiency of this can be high.)

That's really neat! I've mostly seen explanations about Hydrogen as a vehicle fuel so I've never stumbled on cavern storage. It makes sense to use isothermal compression. Especially if you can recover the energy from decompressing the hydrogen using a turbo expander which would be obscenely difficult on a vehicle.

Why would it be difficult in a car? It is the same principle as a compressed air car: https://en.wikipedia.org/wiki/Compressed-air_car

Re: Solar energy solves global warming

#107

Post by jussij »

pfdietz wrote: post #85
mirko22 wrote: post #59

Earlier quoted context omitted.

And they will be there for half a century as opposed to wind turbines and solar panels which will have to be replaced and are hard to recycle…

It would be perfectly fine if we just landfilled wind turbines and solar panels. It's not like silicon or fiberglass are rare. The whole recycling business here is more fetish than obstacle.

There are problems with recycling in general. For example, the overuse of plastics, with no sensible recycling plan means we have plastic garbage patch twice the size of Texas floating around in the Pacific Ocean. These problems are generally not about recycling, but rather the willingness of governments to legislate sensible solutions.

Re: Solar energy solves global warming

#108

Post by ianburrell »

pfdietz wrote: post #103
ianburrell wrote: post #80

Earlier quoted context omitted.

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.

It also can make sense to add limestone (or other carbonates) to the ocean. As long as you don't make the ocean too alkaline, you get the following net reaction: CaCO3 + CO2 + H2O --> Ca(+2) + 2 HCO3(-1)

Seeing as climate change is making the ocean acidic, making it alkaline would be a good thing.

Re: Solar energy solves global warming

#109

Post by foxyv »

_hypx wrote: post #106
foxyv wrote: post #100

Earlier quoted context omitted.

That's really neat! I've mostly seen explanations about Hydrogen as a vehicle fuel so I've never stumbled on cavern storage. It makes sense to use isothermal compression. Especially if you can recover the energy from decompressing the hydrogen using a turbo expander which would be obscenely difficult on a vehicle.

Why would it be difficult in a car? It is the same principle as a compressed air car: https://en.wikipedia.org/wiki/Compressed-air_car

A turboexpander in a car would add an obscene amount of cost to an already expensive fuel cell vehicle. Also, it would be a fire and explosion hazard requiring a ton of maintenance.

Re: Solar energy solves global warming

#110

Post by foxyv »

rich_sasha wrote: post #105
foxyv wrote: post #96

Earlier quoted context omitted.

E-Methanol is okay as a carbon neutral fuel and solvent. At 50-60% efficiency it makes an excellent fuel to create from electricity. But it is still a long way from competing with battery and pumped hydro. It's fuel cell efficiency is only 30% with current technology after the 40-50% losses from the creating of the fuel itself. You can buy a lot of transmission wire at that price point. All of these technologies illu…

But I guess you can make a lot of methanol in summer and burn it in winter, storing it cheaply for months. Batteries so far seem maybe ok at balancing diurnal power generation / use patterns but not seasonal storage.

Yeah, it is definitely not a bad idea for heating fuel, feed chemical, racing fuel, jet fuel, etc... Just replacing the natural gas produced methanol would be nice. However, wind energy has high availability in the winter and batteries would make up for blizzards and shortfalls. Canada is having a lot of good results from wind energy. In addition, they make a ton of energy from hydroelectricity.

Every country is different, E-methanol may be a solution for a few places. However it is not something I would personally invest in.

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