The Death Of Fossil Fuels

[bjn]

But I don't think anyone would be suggesting building one huge machine to deal with the whole world's emissions. Why don't you try to figure out how many reasonably sized machines the UK would need?

I don’t think he was suggesting one big machine

I definitely wasn't. I was trying to put a bound on how big a problem it was from a simple infrastructure point of view. For the UK you'd need about 2km^2 of inlet for beuafort 4 air speeds. That is 4 million 1x1m inlets moving air at 24km/h all day and all night. Arrange those square meters as you see fit. You'd need more if you run at a lower airspeed.

They would all need to be clustered near to where ever you were dumping the carbon. I have a feeling this might kick up a fuss at serried walls of these things hundreds of meters long making noise all day and night.

[bjn]

The calculation in the Wired article only looks at the energetic cost of capturing the carbon from the air. Essentially that treats the sequestration as energetically free, which thermodynamically is true - the combination of wet basalt and CO2 is energetically favourable, just very slow. So far, there has been a lot of focus on carbon sequestration, but actually the carbon capture is the more difficult bit. People think about capturing carbon from vents of power stations, and think it must be straightforward to capture it all. But actually the processes tested so far capture quite disappointing proportions of it. You'd have to be capturing 90%+ of the CO2 from a methane power station to get something properly worthwhile, and I don't think anything near that has been demonstrated at scale.

If we are going to burn methane to spin things for a while yet and want to perform carbon capture on the exhaust gasses, the Allam cycle seems to be a good way to do that. You burn methane with pure oxygen that has been seperated from air, and you do that in a supercritical CO2 environment with no other gases. The results are water, CO2 and heat. The heat expands the CO2 working fluid, which drives a turbine. You recycle most of the CO2 back to the combustion chamber, bleed of the excess pure CO2 and the water. No NOX or other crap to deal with. It's also highly efficient, more than making up for the energetic cost of seperating O2 from air and compressing the CO2 working fluid. Post combustion carbon capture is trivial compared to burning methane in air, you just connect a pipe to the CO2 outlet.

There is one currently being built in the North of England https://whitetail.energy/

[IvanV]

If we are going to burn methane to spin things for a while yet and want to perform carbon capture on the exhaust gasses, the Allam cycle seems to be a good way to do that. You burn methane with pure oxygen that has been seperated from air, and you do that in a supercritical CO2 environment with no other gases. The results are water, CO2 and heat. The heat expands the CO2 working fluid, which drives a turbine. You recycle most of the CO2 back to the combustion chamber, bleed of the excess pure CO2 and the water. No NOX or other crap to deal with. It's also highly efficient, more than making up for the energetic cost of seperating O2 from air and compressing the CO2 working fluid. Post combustion carbon capture is trivial compared to burning methane in air, you just connect a pipe to the CO2 outlet.

There is one currently being built in the North of England https://whitetail.energy/

That's great, to the extent we want to build new methane power stations. But what we really need is a retrofit to existing methane-burning applications, be they power stations, other industrial purposes, space heating, etc, if we are to capture CO2 at scale and reasonable cost. That is what has proved difficult.

[bjn]

If we are going to burn methane to spin things for a while yet and want to perform carbon capture on the exhaust gasses, the Allam cycle seems to be a good way to do that. You burn methane with pure oxygen that has been seperated from air, and you do that in a supercritical CO2 environment with no other gases. The results are water, CO2 and heat. The heat expands the CO2 working fluid, which drives a turbine. You recycle most of the CO2 back to the combustion chamber, bleed of the excess pure CO2 and the water. No NOX or other crap to deal with. It's also highly efficient, more than making up for the energetic cost of seperating O2 from air and compressing the CO2 working fluid. Post combustion carbon capture is trivial compared to burning methane in air, you just connect a pipe to the CO2 outlet.

There is one currently being built in the North of England https://whitetail.energy/

That's great, to the extent we want to build new methane power stations. But what we really need is a retrofit to existing methane-burning applications, be they power stations, other industrial purposes, space heating, etc, if we are to capture CO2 at scale and reasonable cost. That is what has proved difficult.

On top of the engineering pain, with out a punitive cost of carbon, I doubt it will ever be a thing.

[IvanV]

That's great, to the extent we want to build new methane power stations. But what we really need is a retrofit to existing methane-burning applications, be they power stations, other industrial purposes, space heating, etc, if we are to capture CO2 at scale and reasonable cost. That is what has proved difficult.

On top of the engineering pain, with out a punitive cost of carbon, I doubt it will ever be a thing.

That remains my suspicion too. People point to a few places where CO2 is being pumped into holes, though mostly to increase yields from oil fields which seems rather not to be the point. But its its initial capture which remains the difficult bit. Piping it to holes and pumping it down those holes is exhibited, it is just requires spending a lot of money on the pipes and pumps and that.

According to the UK's decarb plans, CCS is essential. Given many other places' greater difficulties with decarb than the UK, it must be even more essential in quite a few of those other places, if it is essential here. We had a demonstration project that got canned, still very incomplete, a decade or so ago and have done very little since. If we were hoping that other people would solve the problem in the interim, well it hasn't happened.

[bjn]

But I don't think anyone would be suggesting building one huge machine to deal with the whole world's emissions. Why don't you try to figure out how many reasonably sized machines the UK would need?

I don’t think he was suggesting one big machine

I definitely wasn't. I was trying to put a bound on how big a problem it was from a simple infrastructure point of view. For the UK you'd need about 2km^2 of inlet for beuafort 4 air speeds. That is 4 million 1x1m inlets moving air at 24km/h all day and all night. Arrange those square meters as you see fit. You'd need more if you run at a lower airspeed.

They would all need to be clustered near to where ever you were dumping the carbon. I have a feeling this might kick up a fuss at serried walls of these things hundreds of meters long making noise all day and night.

That should of course read 2 million inlets of 1m^2, not 4 million. Sorry.

[IvanV]

Chasing efficiency from domestic heat pumps (Wired)
Interesting article. A guy with a not-very-easy-to-insulate-well house, up a big hill near Sheffield, is nonetheless doing very well with his heat pump and getting a SCOP of about 5 from it. Other examples discussed.

It turns out there's quite a bit you can do to get down the cost of your heating, even if your house is hard to insulate thoroughly. Though, unsurprisingly, the most efficient systems are more expensive.

[Grumble]

So glad that Rachel Reeves has announced barriers to onshore wind will be removed. Takes time to get projects like that moving, but I’m hopeful that by the end of this government we’ll be in a much better place.

[Sciolus]

The critical barriers to onshore wind have already been removed, as of Monday. There is a bit more to do (which I think will require secondary legislation) to make the planning process more consistent with other major projects.

[Imrael]

That's great, to the extent we want to build new methane power stations. But what we really need is a retrofit to existing methane-burning applications, be they power stations, other industrial purposes, space heating, etc, if we are to capture CO2 at scale and reasonable cost. That is what has proved difficult.

On top of the engineering pain, with out a punitive cost of carbon, I doubt it will ever be a thing.

That remains my suspicion too. People point to a few places where CO2 is being pumped into holes, though mostly to increase yields from oil fields which seems rather not to be the point. But its its initial capture which remains the difficult bit. Piping it to holes and pumping it down those holes is exhibited, it is just requires spending a lot of money on the pipes and pumps and that.

According to the UK's decarb plans, CCS is essential. Given many other places' greater difficulties with decarb than the UK, it must be even more essential in quite a few of those other places, if it is essential here. We had a demonstration project that got canned, still very incomplete, a decade or so ago and have done very little since. If we were hoping that other people would solve the problem in the interim, well it hasn't happened.

Late to this, but could places like Iceland with a supply of geothermal energy build and run atmospheric carbon capture as a saleable service. And is there an alternative to sequestration, like chemical fixing into something resembling new coal.

[Grumble]

On top of the engineering pain, with out a punitive cost of carbon, I doubt it will ever be a thing.

That remains my suspicion too. People point to a few places where CO2 is being pumped into holes, though mostly to increase yields from oil fields which seems rather not to be the point. But its its initial capture which remains the difficult bit. Piping it to holes and pumping it down those holes is exhibited, it is just requires spending a lot of money on the pipes and pumps and that.

According to the UK's decarb plans, CCS is essential. Given many other places' greater difficulties with decarb than the UK, it must be even more essential in quite a few of those other places, if it is essential here. We had a demonstration project that got canned, still very incomplete, a decade or so ago and have done very little since. If we were hoping that other people would solve the problem in the interim, well it hasn't happened.

Late to this, but could places like Iceland with a supply of geothermal energy build and run atmospheric carbon capture as a saleable service. And is there an alternative to sequestration, like chemical fixing into something resembling new coal.

I do think we need “all of the above” but CCS has the risk of being a fig leaf for carbon emitters. We should first concentrate on getting emissions down all the way.

Having said that, e-fuels are what you are talking about. Fossil fuel companies are looking into those

[Matatouille]

Late to this, but could places like Iceland with a supply of geothermal energy build and run atmospheric carbon capture as a saleable service. And is there an alternative to sequestration, like chemical fixing into something resembling new coal.

Already happening.

https://www.reuters.com/business/enviro ... 024-05-08/

IIRC they make carbonated water (water also plentiful in Iceland), and frack it into deep granite where the carbon reacts quickly to form a stable mineral. And Iceland has enough suitable rock to deposit humanity's carbon output at the current rate for a millennium or not. The rocks they need are apparently globally common, so if you could persuade a local area to accept fracking there is a good option for sequestration of direct captured carbon without transporting all the way to Iceland.

So yes if we do fall back on direct air capture, Iceland doesn't look like a bad place to do it.

[IvanV]

Late to this, but could places like Iceland with a supply of geothermal energy build and run atmospheric carbon capture as a saleable service. And is there an alternative to sequestration, like chemical fixing into something resembling new coal.

Already happening.

https://www.reuters.com/business/enviro ... 024-05-08/

IIRC they make carbonated water (water also plentiful in Iceland), and frack it into deep granite where the carbon reacts quickly to form a stable mineral. And Iceland has enough suitable rock to deposit humanity's carbon output at the current rate for a millennium or not. The rocks they need are apparently globally common, so if you could persuade a local area to accept fracking there is a good option for sequestration of direct captured carbon without transporting all the way to Iceland.

So yes if we do fall back on direct air capture, Iceland doesn't look like a bad place to do it.

I think carbon capture as a service is an excellent idea. You want to buy some carbon emitting fuel, because other choices are difficult? Well, you have to buy some carbon capture as a service with it. And someone would actually verifiably capture it, we are not in the dubious offsets market.

Yes, Iceland has been experimenting with capturing carbon in basalt. Because basalt will react with CO2 and hold it, and that's a thermodynamically feasible reaction that requires no energy input to make it happen, in a chemical/thermodynamic sense. It requires energy only to put the things in the right places, including drilling holes, fracking the rock, and maintain the pressure to try and make it happen at an appreciable speed. It's helpful that its really rather warm down there in Iceland. You say quickly, and it is quick in comparison to many natural carbon capture processes, but not quick by comparison to many processes in chemical processing plants. I think it takes some months for most of the CO2 they pump down to be sequestered. As it says there, the first trial plant had a capacity of 4,000 tonnes/yr. Now there's a new plant of 36,000 tonnes/year.

The UK emits around 5 tonnes per person per year, and I think Iceland rather more, for all their hydro and geothermal, because of all their aluminium processing. So these are really very small amounts. They hope to get up to million tonnes/yr by 2030, and gigatonne by 2050. And this is going to involve a lot of drilling holes in lots of places as gigatonnes of carbonates are formed in the earth's crust. But there are many gigatonnes of basalt there in Iceland. A cubic km of basalt weighs about 4 gigatonnes. So there is potential to make it really something in 25 years. To make it really really something we need to see similar developments in other places with a lot of warm basalt. And there is no shortage of warm basalt, it tends to be around places with warm crust.

[lpm]

It'll be interesting to see how it works in the 2200 to 22000 time frame.

Iceland could become the thermostat. Dial CO2 up and down to stabilise temperatures, prevent ice ages. Will be exciting to watch how it develops.

[Grumble]

Ed Milliband getting off to a flyer with some easy wins - approving some big solar farms and promising to make it easier to fit home solar. Seems like he might make it compulsory to fit solar to new homes as well.

[IvanV]

Starmer pledges enough new offshore wind to power 20m homes in next 5 years (Grauniad)

That horrible and opaque measure of wind capacity, how many homes it powers. In objective measure, the quantity to be built is 20-30GW. Quite a range of uncertainty that. And that will be maximum nominal capacity, not what it produces on average taking into account the variation in wind and transmission constraints. So 20-30GW is actually something like 7-10GWe on average (ignoring transmission constraints), assuming something like 35% capacity factor on average for offshore wind. (I plucked that from memory, might not be quite right.) That compares with about 30GWe being the average demand for electricity at present. And domestic demand is about 40%, 12 GWe, so that is roughly consistent with something like 20m homes worth I suppose, given something like 28m homes.

This makes clear that Ed Milliband's "mission" to "decarbonise the grid by 2030", for which he has appointed Chris Stark recently head of the CCC as his "mission lead" will not really be achieved except in some greenwashspeak. But we knew that anyway. Adding this quantity of wind power to the grid is only a step in that direction. Currently 41% of UK electricity is renewable, which probably includes some dubious ones like Drax. This in principle can add about 30%, if we ignore issues of increasing wind constraints when it's a windy day. And there remains the very difficult issue of what do you do at less windy, less sunny, moments and weeks and months. And if there is any large movement towards heat pumps and electric cars, then electricity demand will begin to grow, after a couple of decades or so of slow demand reduction due to efficiency.

But what is significant is that this will be developed by Great British Energy. The recent seabed auction didn't get any bids, because the government set the minimum terms in such a way that no one was willing to actually pay money for it. This includes issues such as construction price inflation - wind turbines have gone up in construction cost for the same reasons all construction costs have increased - and what the price of electricity might be. But when it is a nationalised industry, you can just tell them to do it, and they just do it, provided you make available to them the requisite capital.

The Chinese actually have quite a good approach to this kind of thing, at least in the toll roads sector. If you give someone a concession to build a toll road, they will charge you a large premium for the risk of how much demand it might get. So the state, mainly through provinces, builds toll roads and opens them, and then when you can see what the demand for them, then it concessions them. And so it gets its capital back, which it can then recycle to build the next toll road. It helps that road-building is a fairly standard task, so having it built in the public sector doesn't tend to result in massive inefficiencies. Building wind turbines is similar.

[Grumble]

Electricity demand will grow, but not necessarily peak demand. If we get demand side sorted then we could flatten the demand curve, or match it to renewable supply more closely.

[dyqik]

Electricity demand will grow, but not necessarily peak demand. If we get demand side sorted then we could flatten the demand curve, or match it to renewable supply more closely.

Electric car demand, in particular, is not linked to peak demand, provided there are enough chargers that they can be left plugged in through low demand times. Most cars are parked most of the time, and can charge whenever. Enough chargers is probably the most difficult thing to deal with in the UK though.

That's before you use electric car batteries to flatten demand peaks.

Heat pumps will tend to need to work hardest in the early mornings, before industrial demand really picks up, and in the late afternoon (for heating to some degree, but more when used for cooling). In the US, that late afternoon is the domestic energy demand peak, as cooking appliances and AC are working hardest.

The biggest cooling and heating loads tend to coincide with sunny and windy conditions.

[IvanV]

Electricity demand will grow, but not necessarily peak demand. If we get demand side sorted then we could flatten the demand curve, or match it to renewable supply more closely.

The usual prediction for future electricity demand, if we do succeed in making major decarbonisation by 2050, is at least double present demand. That can't happen without increasing peak demand. Indeed some have suggested peak demand might more than double. Though that typically comes in a scenario where many people arrive home early evening and plug their cars in. But clearly there is scope for retiming car charging demand, so that seems a bit unnecessary.

In a world with a lot of interruptible supply, matching supply to demand is actually more important than just trying to lop off consistent peaks. If the wind is blowing hard in the early evening, and that is often a relatively windy time of day, then let people consume then. Whereas the small hours are on average a less windy time of day.

[lpm]

Though that typically comes in a scenario where many people arrive home early evening and plug their cars in. But clearly there is scope for retiming car charging demand, so that seems a bit unnecessary.

Already cars don't charge when they're plugged in. Unless the car's owner is an idiot who is paying peak prices of 24p/kWh or whatever it is.

You just plug in and Octopus charges at the time they choose, for 7p/kWh. During the night it's all automated, Octopus computers switch the charger on and off according to whatever demand management they want.

Also, Octopus message each week, saying greenest charging days are forecast to be Weds and Sat, or whenever. They gave me 10p because I plugged in last night rather than Tues night. This is all stupidly manual at the moment. But that will evolve.

There's no reason why demand can't be almost completely shaped to match supply, in summer at least.

[IvanV]

There's no reason why demand can't be almost completely shaped to match supply, in summer at least.

Charge time profiling is mainly available for people having their own charger they can plug into. You can go even further and export power from your car battery and top it up later, though that often requires a special charger to be able to export. But many people cannot install their own charger. It is less clear how people who have to use public chargers can access these services. Not least because it requires being plugged in for extended periods when you are only charging for some part of that time, when there might be neighbours wanting some too.

As things stand, most people who currently buy electric cars are people who can install their own chargers. But we need to make public charging sufficiently attractive that inability to install your own charger ceases to be such an impediment. And extend this kind of service to public chargers too.

[bjn]

That horrible and opaque measure of wind capacity, how many homes it powers. In objective measure, the quantity to be built is 20-30GW. Quite a range of uncertainty that. And that will be maximum nominal capacity, not what it produces on average taking into account the variation in wind and transmission constraints. So 20-30GW is actually something like 7-10GWe on average (ignoring transmission constraints), assuming something like 35% capacity factor on average for offshore wind. (I plucked that from memory, might not be quite right.) That compares with about 30GWe being the average demand for electricity at present. And domestic demand is about 40%, 12 GWe, so that is roughly consistent with something like 20m homes worth I suppose, given something like 28m homes.

You might want to adjust your numbers, the Halide-X turbines going into Dogger Bank have a capacity factor around 60%. A combination of it being windy out there and being really tall so get above the still layers of air near the surface.

https://www.gevernova.com/wind-power/of ... re-turbine

[Gfamily]

It would be interesting to see the economics (and explore the behavioural changes) if Great Britain Energy installed PV panels on all newbuild homes, with the option of a home battery being installed if the developer or first time owner thinks it's worth it.
Ownership of the panels/inverters etc. would remain with GBE, and there probably wouldn't be a feed in tariff (or maybe a reduced one). Battery owners would see the biggest benefit, but their load smoothing could be one of the biggest benefits for the grid.

[IvanV]

That horrible and opaque measure of wind capacity, how many homes it powers. In objective measure, the quantity to be built is 20-30GW. Quite a range of uncertainty that. And that will be maximum nominal capacity, not what it produces on average taking into account the variation in wind and transmission constraints. So 20-30GW is actually something like 7-10GWe on average (ignoring transmission constraints), assuming something like 35% capacity factor on average for offshore wind. (I plucked that from memory, might not be quite right.) That compares with about 30GWe being the average demand for electricity at present. And domestic demand is about 40%, 12 GWe, so that is roughly consistent with something like 20m homes worth I suppose, given something like 28m homes.

You might want to adjust your numbers, the Halide-X turbines going into Dogger Bank have a capacity factor around 60%. A combination of it being windy out there and being really tall so get above the still layers of air near the surface.

https://www.gevernova.com/wind-power/of ... re-turbine

Yes, it seems the offshore wind capacity factor keeps going up as taller turbines are introduced. Older off-shore farms achieve near what I said. But the sector average was 42% in the last 12 months, as newer, taller farms have come in. Though there may be a degree of luck as I think the last 12 months was relatively windy. If these new even taller ones can get near or over 60% capacity factor, that is quite a remarkable improvement, and quite a game-changer.

Though calms still happen. It was very calm the night before last, and metered wind output fell to 0.25GW at midnight. That's actually the 2nd time this month it was that low, though getting that low is fairly uncommon. But this is a time of year we often tend to get such calms.

[dyqik]

It would be interesting to see the economics (and explore the behavioural changes) if Great Britain Energy installed PV panels on all newbuild homes, with the option of a home battery being installed if the developer or first time owner thinks it's worth it.
Ownership of the panels/inverters etc. would remain with GBE, and there probably wouldn't be a feed in tariff (or maybe a reduced one). Battery owners would see the biggest benefit, but their load smoothing could be one of the biggest benefits for the grid.

An somewhat alternative version would be for planning to require that PV be installed (and houses shaped to maximize the use of it - roof slope direction is largely optional in the planning phase, and incentivising steeper roof pitches could increase the effective area of panels in winter), with GBE being the owner of last resort, if the new home purchaser didn't want to buy it with the new house.

The PV installation could be paid for by either the developer or GBE.