Hacker News Reader

Comment by scottlocklin | Hacker News Reader

I don't even know why this is a question. So, people burn hydrocarbons for energy. How do you expect to capture the carbon piece into a stable compound that can be buried without expending more energy? Please draw this chemical reaction out, along with energy balances and how endothermic it is.

The idea that you could do this belies total ignorance of chemistry, fossil fuel genesis and the laws of thermodynamics. Life actually does a pretty good job of turning CO2 into dirt which gets buried -encouraging that rather than building some preposterous contraption involving mineshafts seems a little more sensible.

View on HN

The point of carbon capture isn’t to be energy neutral. The point is to be able to take clean energy (say nuclear energy in the United States) and capture carbon from dirty uses (say construction in India).

Carbon capture will have to work because there will be no way to address climate change otherwise. Countries like India and everyone on the continent of Africa will industrialize, they will build vast structures out of concrete and they’ll use cheaper gas power cars and whatever energy they can get their hands on. My home country of Bangladesh will add a 80-100 million people and it’s GDP will increase by a factor of 5 by 2050. The idea that Bangladesh will jeopardize a single percentage point of GDP growth to make that growth carbon neutral as it rushes to bring middle income standards of living to its people is utterly absurd. The country’s CO2 emissions per capita has increased by a factor of five since I was born and it can increase by another factor of 10 before getting to the level of an efficient developed country like France. To compensate for massive CO2 output in those countries, developed countries will have to go carbon negative and capture that CO2.

It’s so obvious I’m not sure how so many people overlook it.

Surely the people of Africa or Bangladesh are not so stupid as to not learn lessons from the US. We have better technology now, so they will use that in a lot of cases.

Don't get me wrong, there are cases where the old way is better because it is cheaper and so they will use that. However they won't use gas cars since we are developing battery cars, solar panels, and the like. Within a few years electric cars will be better for them as well.

It’s not a matter of “stupidity,” but the desire for a better life. A “do nothing” climate change scenario will be bad for Bangladesh, but not as bad as hampering economic growth. By 2060, it will cost Bangladesh a third of its GDP. But put differently, losing a single percentage point of annual GDP growth over that period will be just as bad as the impact from climate change.

New technology will be adopted, but not fast enough. Bangladesh is currently at 4% renewables. But half the country doesn’t even have electricity. It’s building 10 GW of coal capacity by 2030 which will double per capita CO2 output. Gas is still the major energy source with some nuclear being built. There is nowhere to build solar or windmills, though off shore wind is a possibility in the long term. It will be many decades before Bangladesh uses primarily electric vehicles and vast numbers of ICE vehicles will be purchased in the meantime. The number of registered motor vehicles has tripled in the last decade—those are nearly all gas vehicles, and half are used vehicles imported from elsewhere. 80% are motorcycles, with very inefficient gas engines. And there are no alternatives to CO2-production for many construction and industrial processes.

Bangladesh will certainly take some measures to be greener. It has no economic incentive to use more fossil fuels than it needs to: it imports gas and coal and has no domestic industry or jobs in that area to protect. But it also can’t afford to subsidize renewables. It will deploy technologies based on true cost, and right now the cost of renewables + storage isn’t there, neither is the domestic infrastructure to go fully electric.

>A “do nothing” climate change scenario will be bad for Bangladesh, but not as bad as hampering economic growth.

Citation very much needed. Everything I've read about global warming tells me the eventual GDP impact of 'business as usual' warming will dwarf everything else. It's not just the flooding. It's the rise in wet bulb temps, the droughts, the forest fires, etc. This does not magically end at 2100 just because our projections end there. This goes on for millenia.

I cannot fathom, how one could look at the facts and science and come to your conclusion.

Compounding effects.

$1,000,000 5% over 80 years = $49,561,441.07

$1,000,000 4% over 80 years = $23,049,799.07

I don't even think the most outlandish have climate change being greater than 50% of GDP.

>... tells me the eventual...

To you this is an eventuality, to them the problems are right now, it is right now that they need electricity for the X million people without access to it, it is right now that they have to use huge amounts of concrete to build infrastructure, it is right now that they have to expand their transport/truck fleets to transport food to themselves or the million/several hundred thousands of Roinhya which arrived to the country in the last 2 years

Walk 100 miles in the other person's shoes

A ton of research has been done on the economic impacts of climate change, accounting for those environmental effects. E.g. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...

The mainstream “facts and science” does not support the conclusion that climate change will eventually “dwarf everything else” in the economy, not even for hard-hit countries like Bangladesh. The 1/3 number for Bangladesh by 2060 is one of the higher estimates I’ve seen, from Asian Development Bank. Others show less than 10%.

See also: https://www.washingtonpost.com/weather/2019/08/19/climate-ch... (“Climate change could cost the U.S. up to 10.5 percent of its GDP by 2100, study finds.”).

10% is a lot! It’s trillions of dollars, and it would be worthwhile to spend a significant amount of money to avoid it. But we need to pay attention to the science.

I'm not sure what the argument is here, because no matter how persuasively you write the message board post, the empirical evidence seems to support Rayiner's argument, which isn't that carbon is good, but that the developing world is carbonizing far more rapidly than the developed world is decarbonizing.

Negative externality.

If electric cars really are more practical, we'll see that reflected in their adoption.

Electric cars will certainly be adopted eventually, because electric cars have an order of magnitude fewer parts , but in the short term ICE cars have a far more mature production line (a century of mass production) whereas EVs have been in proper mass production for maybe a decade, and their manufacturing processes are rather immature and changing/improving quickly as a result, but we need to deal with climate change now not once EV chains stabilize.

Yes, but do the patent holders or companies making that better technology see their side of the task: they need to give the developing countries that technology. The problem is that would mean giving a country that can manufacture more cheaply than they can the only thing left as a differentiator.

It's not up for them to try and learn from us, it's up to us to teach them.

Patents are only for about 15 years. Most of the important ones have expired already, the rest will in the future. (unlikely copyright).

Developing countries get their cars from developed countries. In 30 they will not have a choice about buying gas cars. 30 years is not that long on a global scale.

But 30 years is a long time on the climate change scale. To meet IPCC 1.5C and 2C targets we need to dramatically reduce emissions by 2030. Instead, they will continue to grow rapidly due to development in places like Bangladesh.

> they will continue to grow rapidly due to development in places like Bangladesh.

Your average Australian consumes many times over the co2 budget than a Bangladeshi, Sudanese or Nigerian combined

To reduce these emissions of the developed world is a far more important objective than Bangladeshis building a couple coal plants so they can give electricity to more than just 40% of their population

That widely misses the mark. There are sixteen times as many Bangladeshis, Sudanese, and Nigerians as there are Australians. And while Australia’s CO2 emissions are declining even as its economy keeps growing, emissions in Bangladesh are growing exponentially. Australia is a mature economy, while Bangladesh’s is currently doubling every decade, and it has many doublings to go before it reaches middle income status. That will come with huge increases in CO2 emissions.

Europe and North America now account for well under 40% of CO2 emissions and their emissions are shrinking: https://ourworldindata.org/grapher/annual-co-emissions-by-re.... Emissions in the rest of the world, by contrast, are increasing exponentially. Within a decade or so, India alone will emit more CO2 than the EU.

The current CO2 budget for sticking to 1.5C is about 400 gigatons: https://www.carbonbrief.org/analysis-why-the-ipcc-1-5c-repor.... North America and Europe could cut their emissions to zero tomorrow, and the rest of the world will easily blow through that within the next 20 years. China by itself will use up that whole budget by 2050 if not earlier.

Visiting Central America, I noticed all the "hand me downs" from North America. This will be the challenge- new electric cars which are 10% cheaper than new gas cars won't be deployed there, because old gas cars are 90% cheaper than new electric cars.

The good news is the problem will eventually take care of itself when North America doesn't want its old Nissan Leafs anymore. The bad news is the delay.

In 20 years old electric cars will be all they can get.

> Surely the people of Africa or Bangladesh are not so stupid as to not learn lessons from the US.

Well, everyone everywhere right now keeps doing the stupid thing, despite knowing better.

The fuel is too cheap. Right up front, it needs to include the cost of its clean up.

If it is absurd to think that Bangladesh would jeopardize their growth in interest of lowering emissions, how is it not absurd to think that developed countries should neglect their own economic interests in favor of going carbon negative to compensate for countries such as Bangladesh?

Because it really makes more sense to plan for the eventuality where anything we do makes a difference than the far more likely one where this entire trainwreck just keeps going straight toward a wall. Sure you get some real points for cynicism before rock meets hard place, but it doesn't count for much outside of that.

I of course agree we should do something. I just disagree with the logic that the entire burden falls on developed countries. As well as the magnitude of that burden. Going carbon negative as the parent comment said developed countries "will have to" do, is an incredibly challenging and costly feat.

The pain of climate change will be harder for developed countries to stomach and so they should be more willing to pay to avoid and mitigate it. Consider the forest fires on the west coast of the US this year. They occupied the news cycle for a week. But they killed just 30-40 people. Floods in Bangladesh regularly kill hundreds of thousands of people every year and people for the most part go on with their lives.

I didn't say they would jeopardize their growth. I said they would learn. They might use coal, but it will be a 60% efficient not 1% efficient system like what we used for the first steam engines.

I agree with almost everything you say. But, if any developing country might sacrifice in the name of carbon neutrality, maybe it could be Bangladesh? Bangladesh & neighboring Myanmar are the 4th and 1st non-island nations most vulnerable to climate change.

That doesn't mean it's by any means guaranteed. But facing climate change is in their interest.

But how? They need what little money they have to set up their industries in the first place, it’s not a reasonable request especially in light of how currently developed countries didn’t have to deal with any of that when they first industrialized in addition to ruthlessly exploiting the subcontinent for their benefit. It’s an affirmative action of sorts that will benefit everyone until they’re up to par. China is getting there and I presume the other countries will get there eventually.

Hopefully somewhere along the line we figure out that it's cheaper to help Bangladesh pay for carbon neutral development than to sequester their carbon for them.

I wonder if a private investor could swoop in on a coal plant project, bankroll an upgrade to something better, and sell offsets on the carbon market in California?

That makes a lot of sense.

Carbon offsets have been repeatedly shot down in the past - both as an accounting sleight of hand (for instance, what if it bankrolls a solar plant that was going to be built anyway?), and as a decadent excuse to not actually change anything, equivalent to medieval christians buying Indulgences.

You’re referring to old timey offsets. A lot of direct carbon capture and sequestration are now available as offsets.

> The idea that you could do this belies total ignorance of chemistry, fossil fuel genesis and the laws of thermodynamics. Life actually does a pretty good job of turning CO2 into dirt which gets buried

Coal: about 350m years ago we didn't have trees because lignin had not evolved. Then we got lignin, and trees, and when trees died and fell they just stayed there because we didn't have fungus that could decompose them. Then (about 50m years later) fungus evolved that could decompose trees. All coal exists in that 300m to 350m old seam.

Life takes CO2, turns it into carbon, which is then released when those plants die and decompose.

Forests are a buffer, not a sink.

I had no idea. Where can I read more about this please?

I used a simplification.

Wikipedia has a bit more detail: https://en.wikipedia.org/wiki/Carboniferous#Rocks_and_coal

There's a different opinion on lignin decomposing fungi:

Delayed fungal evolution did not cause the Paleozoic peak in coal production

https://www.pnas.org/content/113/9/2442

Thanks for linking the paper! I've thought the same delay was the case, but seems my knowledge is outdated by 4 years :).

Interesting -- thanks for linking. It's a pity though - I really liked the delay explanation!

I agree with your general comment, but since forests can be used for construction materials they come out a little better than merely being a buffer since the wood gets used in housing or manufacturing in places where steel or concrete would need to step in, both of which are much worse for the environment. If built with longevity in mind, wood framed houses can last around five hundred years, which is more than enough time for technological advancement to allow us to deal with excess carbon by then. Even if they're only designed as typical buildings are, it's still a good fifty years of buffer as wood in a house in addition to the buffer as they were growing as trees.

Forests are a real part of the solution.

I don't know how people are eliding "forests" from my statement about soil. Soil is important and poorly understood[0], which is ironic because it's where most carbon capture is happening now. Forests are nice, and everyone likes forests, but soil is pushing the needle in ways that a shitload of 500 year old houses ain't gonna[1].

[0]https://blogs.ei.columbia.edu/2017/11/13/where-is-all-that-c...

[1] https://www.pnas.org/content/115/46/11652

To be fair, you can never discuss forests in any sort of scientific manner without discussing soils. The two are fundamentally linked.

That said, regenerative agriculture is probably the single best carbon sequestration technology that we have given the raw amount of land we have depleted of its organic matter.

> Forests are a real part of the solution.

Yes, absolutely. I should have been more clear. It's really important that we plant trees, and that we pay attention to the type of tree we're planting and where we plant them.

Static forests are a buffer. Expanding forests are a sink.

Increasing total biomass permanently, e.g. reverting the loss in planetary forest cover, or growing the amount of soil, is a sink.

It's a small, shallow sink, making it effectively still a buffer. It isn't going to help much in addressing an exponentially growing flow. Especially that we won't be able to fully regrow forests anyway - there are more humans now, who need space to live and space for farming.

I thought it wasn't a sink because of methane?

But a buffer helps you flatten the curve. Which is most important in slowing nonlinear processes.

If I was a fiction writer, I'd be writing a book about how humanity used gene drives to wipe out the ability to decompose lignin. Perhaps the original plan was to release the gene into the wild again after CO2 levels normalized, but somehow the gene was lost, and atmospheric CO2 is reaching dangerously low levels...

You're badly misunderstanding the process.

With current CCS you're taking high concentration stream of CO2 from combustion and injecting it into deep subsurface waters that you know will remain isolated. (I'm a geologist - we're good at identifying those.) It's highly soluble in water at those conditions. Ideally it reacts with there and precipitates into other minerals, but it doesn't have to. It's safe in solution as well.

How do CCS actually capture carbon? The article doesn't explain the details.

There are multiple mechanisms. One of the most common is membrane separation, where C02 is selectively allowed to pass through in a relatively high-pressure, C02-rich source such as a literal smokestack. Others are vaguely analogous to the chemical C02 scrubbers you might find in a submarine or in spacecraft.

At present, it's mostly from high density sources that are producing C02. Membrane separation has been around for quite awhile, and works well for that case. It's largely impractical for capturing C02 directly from the air, though.

Direct air capture is the hard part. The "chemical scrubber" approach is being widely tested, but it's hard to make the whole thing carbon negative. It's a tractable problem, but not an easy one.

An interesting theoretical calculation is the rate of entropy production due simply to mixing of smokestack gasses (high partial pressure of CO2) with atmosphere (low partial pressure of CO2). In principle this is wasted exergy -- lots of it. One could imagine some combination of semipermeable membranes and turbines to extract power from the mixing process (your mention of membrane separation reminded me of this). To be clear this is sci-fi though at this point.

(I do believe, however, that there exist methods to extract energy from the mixing of salt and fresh water.)

Likewise, this same idea is a strong argument for capturing CO2 from smokestacks instead of from atmosphere: Fundamentally, it takes energy to undo mixing. And if you want to capture the CO2 eventually anyway, then better to just do that than invent a theoretical "heat engine" driven by the difference in CO2 partial pressure, to get energy that you'll just need to spend somewhere else later (and then some) to get the CO2 back out of atmosphere...

...Actually this phrase "heat engine" now makes me think that maybe this isn't even that hard (in theory) using cold temperatures and phase changes to make dry ice. If it's possible to efficiently cycle the gas through these large temperature swings at all, it must require some kind of heat exchangers and regeneration between stages... (Surely if this were realistic people would have figured out how to do it by now, but it's an interesting thought/design experiment in thermodynamics...)

> Ideally it reacts with there and precipitates into other minerals, but it doesn't have to.

Citations needed.

Have a look at solubility trapping: https://www.co2captureproject.org/co2_trapping.html The others apply as well.

> How do you expect to capture the carbon piece into a stable compound that can be buried without expending more energy?

This is a bit of a strawman. No one is claiming that it will be somehow energy neutral or break thermodynamics. It will obviously require significantly more energy input, not to mention the money. But that doesn't make it impossible or even a bad idea, if the energy fueling the process is nuclear or renewable.

Well, you almost need to be claiming that. If you claim otherwise the energy requirements are truly stupendous. That doesn't event mention that the energy must be green by necessity.

Another commenters on this site (can't find the link) put it like this:

You'd have to drive every mile ever ridden on fossil fuels in reverse. Every single ICE in boats and planes too. All gas, coal and oil plants too. The energy requirements are incomprehensible, truly. We're having trouble going carbon neutral already, but this scheme requires we go neutral and _then some_.

We probably don’t need to capture all of the CO2 though ?

We can combine carbon capture with other solutions for example reforestation ?

I actually wonder if a time might come where global cooling (too quickly) could become an issue. I know that sounds crazy today but suppose we get very good at reducing emissions and CO2, maybe things will require time to adapt too a cooler world.

Eh, you can worry about global cooling as a hypothetical outcome -- for instance, there is a "snowball Earth" feedback loop with the albedo of ice sheets -- but from a geoengineering perspective releasing CO2 into the atmosphere isn't that hard, and we've still got more than half of the known oil in the world left.

We have a very well known set of processes to fix the issue of too few emissions, so I'd doubt that'd ever be a concern.

No, I'm just saying by the time emissions start coming back down, we might need to becareful how fast that happens from an ecological standpoint.

>You'd have to drive every mile ever ridden on fossil fuels in reverse.

No you don't, nature still function...at least for the moment.

You're completely missing the point that you put CO2 into the ground, not unoxidized carbon. So you're ahead by the enthalphy content of those carbon-oxygen bonds. Obviously you need some energy to concentrate the CO2 out of a waste stream and pump it miles below, but that's comparatively trivial.

The climate models clearly show that carbon capture is needed to meet the 1.5-2 degree C target. Without carbon capture of some sort we will very likely have >2 degree C.

Once you come to that understanding, the question is not how do we pay for carbon capture. Rather, it is why wouldn't we pay for carbon capture now so that we avoid the massive costs and negative consequences associated with a >2 degree C rise in global temperatures (droughts, more intense storms, massive human migration, sea level rise, etc.).

You can't just criticize the cost of carbon capture without acknowledging the costs associated with not doing carbon capture.

The good news is we pick the time, the place, the scale- and it can be stationary. It's a political & economic problem, not a technical impossibility.

The reaction between carbon dioxide and alkaline earth silicates is thermodynamically spontaneous in the presence of water, but kinetically hindered. It's a reaction with slow diffusion of reactants through the product layer, limited by surface area. So crush rocks rich in alkaline earth silicates and distribute them in near-shore environments. It's an artificially accelerated version of the geological carbon cycle. It still requires vast-in-absolute-terms amounts of energy to crush billions of tons of rock, but it's not running uphill against thermodynamics.

Olivine:

Mg2SiO4 + 2CO2 → 2MgCO3 + SiO2: ΔH -89 kJ mol/CO2

Serpentine:

Mg3Si2O5(OH)4 + 3 CO2 → 3MgCO3 + 2SiO2 + 2H2O: ΔH -64 kJ mol/CO2

Wollastonite:

CaSiO3 + CO2 → CaCO3 + SiO2: ΔH -90 kJ mol/CO2

https://www.ipcc.ch/site/assets/uploads/2018/03/srccs_chapte... (Section 7.2.2 "Chemistry of mineral carbonation")

We already have catalytic convertors on cars, can we add co2 capture to them as well? Add a little box with powdered olivine and some extra chemical bits to capture a higher % of co2 than absolute 0?

Catalytic convertors already use finely coated incredibly expensive platinum to break down complex molecules, and it is certainly easier to capture co2 near the source than when dissipated in the atmosphere

No. The reaction happens in water, it’s fairly slow, the mixture needs to be agitated, and it would require similar quantities of silicates to the among of hydrocarbons being burned. Better to ignore capture at the source and instead prioritize mass-capture in places that are energy efficient. Shallow coastal areas near major deposits.

A couple of H-bombs in the Himalayas might do the trick quite quickly.

I think the misconception stems from thinking that we could be net-positive energywise. We cannot.

We can (and currently sort of have to) extract energy from fossil sources because our economy runs on hydrocarbons but we will need to expend more energy later to put the extra carbon back where it belongs. The energy we will expend for this in the future has to be renewable.

We are basically borrowing from our future selves and will have to pay back the debt one day.

This is a good summary - and it might just work out. There is a trend in our energy sources being more powerful and more efficient over time. More efficient solar panels, biger and more flexible wind turbines, bigger and safer nuclear reactors. So paying the "energy dept" in the future might be much easier than going without the fosil energy sources right now.

The "borrowing" is not without some side effects which might be hard or impossible to revert in the future.

It's like driving accelerating train without the breaks and hoping that someone builds tracks fast enough that we won't derail

Loss of biodiversity is one big thing. The species that went extinct due to us industrializing the planet, and the species that will go extinct due to climate change (even if brief and ultimately mitigated) will not come back.

Sure, evolution keeps running its RNG and eventually new and interesting species will start showing up. But that doesn't replace the causal link that is lost. Today, the variety of organisms on our planet gives biologists a chance to understand how crucial mechanisms of life evolved. As we erase that history, we make biological sciences that much harder, and by extension, slow the progress of everything from medicine through biotech to chemistry and material sciences.

> but we will need to expend more energy later to put the extra carbon back where it belongs

Is this actually a given? I mean trying to make gasoline from the atmosphere would certainly require more energy than you get by burning it, a lot more.

But I thought sensible capture proposals ran on different chemistry, possibly relying on a wet/dry cycle under which the affinity for carbon is different in the two halves. And letting evaporation (i.e. solar energy) move you from wet to dry. It's not obvious that these must use more energy than you got by burning the coal in the first place.

This was not meant to mean synthetic fuels but that we will eventually have to undo the damages that we currently bring about.

Sure, I agree. The part I question is "more energy later". Or at least, this is not obvious from a first-principles no-perpetual-motion argument. It's a technology question.

From a purely thermodynamic standpoint, you actually _can_ be net-energy-positive.

You're gaining a lot of energy going from CH4/etc + O2 to H2O + CO2.

You're then directly sequestering CO2 (usually in solution in a deep brine), rather than C. You need to expend energy to concentrate the CO2, but it's less than you gain from combustion.

In practice, it's more difficult to come out energy positive overall if we're capturing CO2 at atmospheric concentrations rather than from flue gases/etc at the time of combustion. Regardless, though, "driving roads in reverse" is not a good analogy. We don't need to expend anywhere remotely as much energy as was generated from the original combustion.

Good to know, I'll keep that in mind!

> So, people burn hydrocarbons for energy. How do you expect to capture the carbon piece into a stable compound that can be buried without expending more energy? Please draw this chemical reaction out, along with energy balances and how endothermic it is.

If you read the article, you'd see:

> Nowadays, Industrial production accounts for one-quarter of CO2 emissions from energy and industrial processes. With the demand for cement, steel and chemicals remaining strong to support a growing and increasingly urbanised global population, the future production of these materials will have to be more efficient and emit much less CO2 if governments want to meet their climate goals.

In other words, this technology is not targeted at capturing carbon that is burned for energy.

Well the images of power plants as well as statements like

> Carbon capture, usage and storage (CCUS) refers to a chain of different technologies aimed at capturing waste carbon dioxide (CO2), usually from large point sources of pollution like power plants

> Another drawback of carbon capture, usage and storage, is the considerable amount of extra power it requires, which would increase the cost of electricity

Do give the distinct impression that they're talking about the production of energy (since 'increasing the cost of electricity' would be a weird way to phrase a pure increase in demand). If it was purely talking about processes that also happen to release CO2 then it doesn't make sense to solely talk about carbon capture vs. renewable energy like this article does as that's not an alternative.

Now carbon capture might still be necessary in a fossil fuel free world, but the article puts no real arguments forward why that would be the case.

I agree that the first quote is unfortunate.

For the second quote, I struggle to understand your point. It seems entirely relevant to me.

Having it increase the cost of electricity only makes sense if you see it as part of the electricity production process.

Otherwise it just increases the energy demand of the process, this makes the process more expensive, not energy. Perhaps it could drive up energy prices if it ended up being an immensely profitable use of energy, but that doesn't seem to be the case.

gspr's answer is the primary answer, but a secondary answer is that carbon capture can use a clean cheap power like solar to clean up after power that isn't clean but has other attributes that solar doesn't, like being portable and/or not bursty.

There are predictions that within a decade the price of solar will have dropped so much that it's going to be cheaper to create hydrocarbons by synthesizing them using atmospheric CO2 than it will be to pull them from the ground.

Solar power is anything but cheap. Solar panels are very expensive, short-lived and manufacturing them produces plenty of CO2 and other pollutants.

Nuclear energy is the closest we have to "clean and cheap".

This is precisely reversed. Even the IEA has finally agreed that solar photovoltaic is the cheapest energy in history:

And this is from an agency that is notoriously pessimistic and wrong about solar, vastly overestimating costs of solar and underestimating future deployments. So when the IEA has declared solar cheap, one can be sure that there is zero data to support otherwise.

Similarly, the IEA has been unreasonably bullish about the cost of nuclear, but still places it as one of the most expensive sources of energy.

The data is not on your side, and I have to wonder why you came to believe the things that you are saying.

Perhaps even more importantly, the price of solar has been steadily declining at a faster rate than all other types, and it's been doing it for decades.

One could argue that it will suddenly stop declining in price, but that seems as silly as betting against Moore's law in the 80's. Solar has reached price cutover, and installations are exploding so the manufacturing learning curve should really start to bite.

Where will that continued cost reduction come from? I think there's still a bit of room left, but not a whole lot. The panels themselves are commodities now where many of them are close to materials cost. There's probably a bit of room to cut in racking and in figuring out ways to make installation easier.

Not that any of that is really a problem. Solar is plenty cheap enough, but I don't see a mechanism for it to keep up its precipitous decline in price going forward for many years to come.

Same place all the previous cost reductions came from: a few percent heee, a few percent there.

We are not close to really any sort of physical limitations. We can continue to use less and less material, and come up with designs that require less and less labor per watt.

And there are entire directions we haven't really explored yet to reduce costs even further. For example, panel lifetime. If we can extend panel lifetime by 5 years, that's a 20%-25% reduction in costs. Yet lifetime has stayed fairly constant and unoptimized up until now. 10 years from now we will have a ton of new lifetime data from existing panels that can help us guide the next generation of panels.

I'd argue against that. I was in the solar industry (as an intern) 2008-2009. The amazing decline of the cost of crystalline silicon shortly thereafter was overwhelmingly the driver of panel cost reductions. The basic recipe of tempered glass, encapsulant, cells, soldered stringing, encapsulant, backsheet for the panels has been mildly optimized but has not seen major revolution in quite some time.

The cells themselves also very much are up against physical limits. Last I checked, the theoretical maximum efficiency of a silicon cell in sunlight at the surface of the Earth was something like 29%. The best cells made aren't far from that, and the cells you can actually buy and put into panels en masse are 20-24%. We can talk about multijunction III-V cells, but those are exotic and are unlikely to ever become cheap.

Given the upper bound of efficiency with commodity materials and construction, the only "squishy" places for further cost reductions are improvements in manufacturing efficiency, installation efficiency, and regulatory overhead. On my own home - where I'm installing a 14 kilowatt array - the regulatory overhead is close to 30% of the total cost. That's large, yes, but even if we snapped our fingers and zeroed it, we're still not talking anything close to the gains we've had in the past.

I completely agree that further improvements are going to be "a couple percent here and there" but I don't think that there's a whole lot of total room to cut. We're just not going to see another 10x reduction like we've seen a couple of times since PV became a thing.

Assuming that we WILL expend more energy to capture the carbon, the path to make carbon capture viable is clear: A source of energy that does not add more carbon to the atmosphere.

And existing technologies such as nuclear fission already offers us abundance of energy to do this. The problem is one of scale (how widespread?), acceptability (where can we do this?), cost (who pays?) and time (how soon?).

The process need not be as efficient as nature; if it ‘only’ is both a net win and deployable at a scale that’s larger than we can do by planting trees/stopping cutting down trees, it could be a good idea, even if we get the energy needed for capturing CO2 from burning even more oil.

And no, it need not belie the laws of thermodynamics. The idea isn’t to convert CO2 back to oil or do so without putting in more energy than burning oil gave us. In fact, some capture approaches keep the CO2 as CO2, for example by pumping it into empty oil fields (that makes me think “what could possibly go wrong?”, but hey, what do I know?)

(I have trouble envisioning carbon capture to be a net win and feasible at scale, but I’m not an expert; it might work, just as burning forests to prevent forest fires from spreading has its uses)

This argument basically relies on the assumption that it is at least as energy intensive to convert CO2 into something more solid than the energy you get from burning hydrocarbons to produce that CO2, but I think that assumption isn’t true.

I can’t recall where I saw it and I’m not a chemistry expert but conservation of energy is a thing and there is more potential energy in hydrocarbons than in some simple inert solid molecules containing carbon (which have slightly more potential energy than the CO2 and water produced by combustion). If you can be reasonably efficient then it is possible to extract energy from hydrocarbons without releasing CO2 into the atmosphere. That said, I don’t think there are any sufficiently efficient industrial scale processes to do this.

You're worrying about the wrong part of the equation, the main problem is going to be what you're going to do with the oxygen. There's a reason why so many things tend to react violently with pure oxygen, to the point that we have an entire vocabulary dedicated just to that one class of reactions.

I’m replying to a commenter who claims that it is thermodynamically impossible to extract energy from fossil fuels while capturing the carbon (ie not releasing CO2 into the environment). Obviously some chemistry needs to happen but I claim it is possible to still get net energy out while somehow capturing the CO2.

See this page: https://longitudinal.blog/co2-series-part-2-co2-removal/ with the bit that starts “Note: Interestingly, this is all much less than the heat of combustion”

Well, when nature does CO2 sequestration, it IS energy positive. The overall reaction

silicates + CO2 --> silica + carbonates

is mildly exothermic. This is why most of the carbon on Earth is in rocks, not in the atmosphere.

It implies the use of noncarbon energy sources. For example, ClimeWorks uses geothermal energy for its CCS plant in Island.

Other noncarbon energy sources are nuclear energies (fusion or fission), and the noncarbon renewables wind, solar, tidal...).

I agree with you.

I've been thinking lately a bit about the scale of the problem we face. We essentially need to create enough carbon sinks that balance out all the oil and coal burned since the industrial revolution. Hopefully we do something with it all like build a giant coal brick pyramid.

It's really handy the sun shines light on us for free. I sort of have this crazy idea of turning large parts of the center of Australia into rain forest by using solar power desalinization plants to pump fresh sea water inland. But alas. Australia has carry over credits from Kyoto. She'll be right.

I'm going to reread all the Dune books in the holidays.

Instead of coal. Wouldn't plastics be a better storage material? -> Lego pyramid

The problem with plastics is that (from hazy memory) producing 1kg of plastic might involve the release of 7kg of gaseous CO2. For plastics that are already produced, yes, that carbon's not going anywhere. Producing more plastic to sequester it would somewhat miss the point.

Although a LEGO pyramid would be an amazing archaeological find to leave for future generations.

It would be interesting to see the numbers for bioplastics like PLA. Growing starch-crops without fertilizers is probably the hard part.

With these kind of bricks it would at least not be so difficult to motivate people to find appropriate storage facilities.

Australia shifts away from climate credit cheating.

https://phys.org/news/2020-11-australia-shift-climate-credit...

Yes, it will take a lot more energy. Burning carbon today is effectively civilizational credit card debt. We are prosperous but have a big compounding headache on the horizon.

It may well be impossible to extract excess co2 from the atmosphere at scale. But if it is we are in very very serious trouble.

> The idea that you could do this belies total ignorance of chemistry, fossil fuel genesis and the laws of thermodynamics.

This was many people's reaction to hearing about carbon capture. And one that TFA does nothing to dispel. But I'm not sure that's the final word, it sounds like there may be reversible chemical reactions which can actually capture carbon in an energy-efficient way. One source:

https://manifoldlearning.com/episode-040/#transcript

Gas comes out of a hole in the ground, you burn it, stick the CO2 back into a different hole in the ground eg. https://www.bbc.com/news/uk-scotland-edinburgh-east-fife-492...

Reply on news.ycombinator.com