There's an interesting piece on the economics of carbon capture at
http://www.softmachines.org/wordpress/?p=2346
and the implications for current UK political strategy.

" without subsidies or other intervention"

How about the subsidies for fossil and nuke are also removed, level playing field...
"£10.5bn a year in support for fossil fuels in the UK"

This is mentioned in the linked article, but not all industrial processes can be made CO2 emissions free, like cement manufacture. Also fuel may be needed for aircraft etc (hydrogen is technically possible but with the obvious perceived risk).

So CCS is helpful as a way to capture some of these emissions, or draw net carbon from the atmosphere if biomass (hopefully mostly waste) is being burned.

Stabilising sea level, for example, requires reducing temperatures to pre-industrial levels, not just stopping at 2 degrees.

Also fossil thermal power plants can be relatively easily switched on or off (dispatchable), which would be useful for filling the gaps in a grid that is largely renewables, or meeting intermediate/peak loads in a nuclear grid.

I wouldn't be surprised if CCS played some small role eventually, but it is not the least-cost emissions-control method at the moment...

Posted By: gyrogearThe simplest & cheapest way to achieve CCS is to start growing hemp on a worldwide industrial basis, then turn it into houses.gg

Providing you don't need the land to grow food

Burning waste, then CCS is a pretty good first step to recovering the raw elements in it: this separates the solids (fly ash and bottom ash) and the CO2. The ash can in principle be mined. Some is currently made into bricks (needs not too much heavy metal in the waste stream).

The CO2 can potentially be made into synthetic fuel, then turned back into plastic. Or buried.

Think CCS is going to be too expensive to allow business as usual, anyway: this is why the pilot schemes have shut down. Renewables are just cheaper and easier.

Hydrogen powered aircraft are a potential solution but I wonder whether airlines/public will be willing to accept them based on safety fears (whether justified or not). Also, you have to capture the resulting water rather than dump it in the stratosphere, because this is otherwise almost as bad as CO2.

If you go to net negative emissions, you can bring down CO2 levels faster than on a 1000 year timescale, but this is obviously an issue for future generations.

Note that the Europe 100% renewables plan you linked to involved burning quite a lot of biomass. So I guess I should have said that dispatchable thermal power plants are useful for keeping the lights on whether or not they burn fossil fuel. How much biofuel is sustainable anyway? Probably not very much. Burning biomass in Drax is not counted as 'renewable' by some accounts...

Posted By: finnianAlso, you have to capture the resulting water rather than dump it in the stratosphere, because this is otherwise almost as bad as CO2.

It looks like an alternative is to avoid / minimise creating contrails, as it's the cirrus cloud they cause that results in most warming. There already seems to be work on that, and that the absence of soot / sulphur / NOx from a hydrogen engine / fuel cell helps too, as their presence causes nucleation of ice crystals.

https://www.reading.ac.uk/news-archive/press-releases/pr586136.html
https://www.nature.com/articles/s41467-018-04068-0
https://dspace.lib.cranfield.ac.uk/bitstream/handle/1826/2966/Noppel%202007.pdf

Also, the climate effects of planes are complicated: agree that contrail production is major but other effects (combined) possibly slightly bigger..

https://www.carbonbrief.org/explainer-challenge-tackling-aviations-non-co2-emissions

Looks like NASA are spending some small change on aircraft fuel cell technology: https://grainger.illinois.edu/news/30918

I've heard of "green power", but lemon sherbet power sounds much more interesting...

gg

Resurrecting this thread a bit ...

Has anybody else come across Climeworks and especially the Orca plant?

It seems they actually are pulling CO2 out of the atmosphere and with some help from Carbfix are entombing it as stone.

https://climeworks.com/
https://climeworks.com/roadmap/orca
https://www.carbfix.com/

It appears to be real, and you can subscribe as an individual, although a few individual billionaires would no doubt be better. I'm thinking of signing up so what does the team think?

The one problem I can see at the moment is that it is expensive though they do have pretty graphs showing the cost coming down?

Posted By: WillInAberdeenIn future that energy might be useful for something else, like a data centre or exporting hydrogen

This is an argument that often comes up around novel uses of renewable energy. Of course it's true but I think its emphasis is unhelpfully misdirected.

It's usually used to cast doubt on some novel use of renewable energy, or at least flagged as a snag or caution. Using renewable energy for bitcoin mining is a prime example - the mining 'community' boasts of progress in decarbonising - if a mining 'farm' uses renewable, then it's OK, no longer a climate disaster. The anti-mining 'community' points to all the existing (therefore more worthy/vital) things that could be decarbonised if mining wasn't swallowing so much renewable. The miners say that much renewable capacity wouldn't have been created it they (the miners) weren't there to create demand - especially in the case of miner-dedicated wind farms.

Every novel use of renewable gets this treatment. But surely the point is, that once again 'the market' can't be relied on to make optimum allocation decisions - how much should be invested in renewables, and what it should be used for, to best possible climate effect. The assumption is that human society, advised by science, can't rationally and wisely simply make such decisions - so it has to be left to some 'hidden hand', which no-one can actually locate or even (like dark matter) deduce the properties of.

They mention using 2650 kWh per t of CO2, and 10 billion t per year, so I think that works out about 3000 GW of green energy needed, minus future efficiency improvements.

For scale:
Average electricity usage in Europe, all sources: 300 GW
Power station CCS: 300 kWh per t

@Tom,
Lots of people (including some scientific advisors!) have struggled with that allocation problem (as you know) and tried all sorts of measures of marginal intensity and EROEI to show whether the carbon or energy consumed by something is 'a lot' or 'not much'. Eventually it comes down to "who else could have used that energy better?" which is opinion.

For example, my supplier claims they only sell me renewable electricity, so is it ok for me to mine bitcoins all night with my windows open and all the lights and heaters on, thus creating demand for renewable generators? Most people would say that's not ok, because we know that the energy I'd use, although renewable, is a limited resource that would be useful for someone else, and it wouldn't hurt me to conserve it.

But what if I lived in a region where more renewable electricity is being generated than the people living there can use? (I do, btw). Still need to conserve it, say most people, so the surplus can be used to displace emissions that would have happened elsewhere.

But what about long into the future, when all energy everywhere will be zero carbon? Well then it might be ok for me to use lots of it, as I wouldn't be depriving anyone else.


@DJH, Undoubtedly net CO2 removal is needed - like I said, we need all the options we can get. If there's a choice between closing a lot of fossil power stations early, versus keeping them open so there's spare power for this, then I'd rather use fewer kWh per t to capture concentrated chimney CO2 first, ideally from biomass power stations. AS WELL AS maturing this technology ready for wider deployment later when those GW might become available.

Posted By: WillInAberdeen
But what about long into the future, when all energy everywhere will be zero carbon? Well then it might be ok for me to use lots of it, as I wouldn't be depriving anyone else.

Yes, hopefully that's the future. I'd hope that

Posted By: fostertomhuman society, advised by science, [can] rationally and wisely simply make such decisions

rather than leaving it to the 'hidden hand', a theory which gives individuals and corporations license to do whatever they feel like.

edit: I've just noticed that Simon's link is actually the same as the one I suggest. The problem is that when I go to that link, it loads instead https://en.klimatkarusellen.se/post/energy-and-politics-in-the-wake-of-the-climate-debate

I think there's something screwed up in the site's localisation and javascript handling. The key is to select Swedish language for the original article. Unfortunately they then hide the URL of the PDF so I can't give a direct link to that.

SimonD claimed https://www.klimatkarusellen.se/post/energy-and-politics-in-the-wake-of-the-climate-debate would show something interesting. But it actually shows:

We Couldn’t Find This Page
Check out some of the other great posts in this blog.

and clicking on that button reveals

No posts published in this language yet
Stay tuned...

But if you start instead at

https://www.klimatkarusellen.se/post/energy-and-politics-in-the-wake-of-the-climate-debate

Then you get a Swedish blog entry where at the end is a link to PerFahlen uppdaterad.pdf

which is a 68 page mixed English-Swedish document where it seems most of it can be read in English.