/ Audi creates diesel from CO2 and water!

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Timmd on 16 Sep 2016

This is amazing, the possibilities and their implications are huge for this (imho)...

http://csglobe.com/audi-creates-diesel-fuel-water-co2-leaves-zero-carbon-footprint/
wintertree - on 16 Sep 2016
In reply to Timmd:

It's not very amazing when you look at the overall efficiency...

3
Timmd on 16 Sep 2016
In reply to wintertree:
Interesting point, I think it could become amazing if renewable means of generating power improve enough to make it a viable alternative to diesel from fossil fuels. Improvements in engine efficiency could help towards that too, and changes in usage...
Post edited at 21:38
gethin_allen on 16 Sep 2016
In reply to Timmd:
The only problem is producing the high temperatures and pressures required to do this. I guess we could burn gas, oil or coal for this.
Oh, and the electricity. That's fine we have electricity from gas and coal fired power stations.

I guess it could be a use for nuclear generated electricity at low demand times.
Post edited at 21:41
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wintertree - on 16 Sep 2016
In reply to gethin_allen:

> I guess it could be a use for nuclear generated electricity at low demand times.

Yup and also for storing excess renewables. However it's likely more efficient to synthesise methane instead and to inject it into the gas grid - plenty of storage there - and using it in CCGT generation and/or methan cars.
wintertree - on 16 Sep 2016
In reply to Timmd:

> Improvements in engine efficiency could help towards that to

Not really. Thermodynamics imposes limits on the maximum efficiency of internal combustion engines and real engines are approaching these limits meaning there's not much room left to improve.

Timmd on 16 Sep 2016
In reply to wintertree:
> Not really. Thermodynamics imposes limits on the maximum efficiency of internal combustion engines and real engines are approaching these limits meaning there's not much room left to improve.

Which, to be pedantic in the spirit of UKC, doesn't mean that they couldn't help, if there is still some room left to improve.

Edit: More seriously, do you have figures in mind which make you think that engines are approaching a point where there is no room left for improvement?

I have just come across this, talking about Cummins aiming for 55% fuel efficiency for their large diesel engines.

http://articles.sae.org/14388/
Post edited at 22:22
Bob Hughes - on 16 Sep 2016
In reply to gethin_allen:

> The only problem is producing the high temperatures and pressures required to do this. I guess we could burn gas, oil or coal for this.

> Oh, and the electricity. That's fine we have electricity from gas and coal fired power stations.

In the article they use a renewable source (solar, wind or hydro) to heat the water

elsewhere on 16 Sep 2016
In reply to wintertree:
If you consume electricity at a time you are otherwise paying windfarms not to produce that is a real money saver for the consumers who ultimately pay the bills.

As a bonus that potentially money saving (ie *better than free) electricity consumption creates carbon neutral deisel to meet an existing demand.

Chemical energy (eg coal, oil, petrol, deisel etc) is great for energy storage compared to batteries and it's associated 'range anxiety'.

The oil supply chain must contain energy representing weeks or months of consumption. Partially filling that up with carbon neutral energy would far exceed the energy that is in pumped storage and other storage capacity.

You can't beat 100% so 70% is good plus it doesn't even need money and energy invested in new electrical storage or distribution infrastructure.

That's a very very positive spin but chemical energy storage (eg a deisel tank or an oil tanker) is just so low tech and incredibly effective compared to pumped storage or batteries.

* http://www.telegraph.co.uk/news/earth/energy/windpower/11323685/Wind-farms-paid-1m-a-week-to-switch-...

PS if you were going to design a fantasy energy system it would be taking CO2 from air to make a fuel that has market and can be used to store energy until it is needed when there is no wind/sun/other renewable generation.
Post edited at 23:00
elsewhere on 16 Sep 2016
In reply to Timmd:
The limit imposed by thermodynamics can be much lower that 100% (40%??? for petrol, higher for diesel) so 55% may be close to the limit. You can be a long way below 100% efficiency but still not have much room for improvement.
Post edited at 23:02
wintertree - on 17 Sep 2016
In reply to elsewhere:

> If you consume electricity at a time you are otherwise paying windfarms not to produce that is a real money saver for the consumers who ultimately pay the bills.

Agreed.

> As a bonus that potentially money saving (ie *better than free) electricity consumption creates carbon neutral deisel to meet an existing demand.

It's not carbon neutral. If that renewable displaced fossil fuels at generation then it would save more CO2 than if it made diesel, due to the increased efficiencies. We need a smarter grid to do this at times of heavy renewable generation, but doing so could be far more efficient than making diesel then hurning it in a car.

> Chemical energy (eg coal, oil, petrol, deisel etc) is great for energy storage compared to batteries and it's associated 'range anxiety'.

Disagree. Plenty of people are doing fine with electric cars and more by the day. They come with between 50 and 350 miles range, the average UK journey is something like 10 miles. So for some people they're no use, but for many people thay are.

It's far greener for those who can use electric cars to do so powered by renewable electricity and those who can't to burn fossil diesel, than it is to use renewable electricity to run diesel cars via synthesis.

> The oil supply chain must contain energy representing weeks or months of consumption. Partially filling that up with carbon neutral energy would far exceed the energy that is in pumped storage and other storage capacity.

I don't know what the capacity is, but it didn't take long when the refineries were blockaded circa 1997 to run out at many garages...

> You can't beat 100% so 70% is good

No it isn't. That's 70% electricity > diesel. Now, what's the efficiency of diesel > motive power? About 45%. Multiply them together and what do you get? About 30% efficiency. Atrocious. Equivelant efficiency with an electric car I think is nudging 80%.

> it doesn't even need money and energy invested in new electrical storage or distribution infrastructure.

Agreed. Although without storage the conversion plant will be running unpredictable and only some of the time - when there's excess. Not a good sign for economy,

> That's a very very positive spin but chemical energy storage (eg a deisel tank or an oil tanker) is just so low tech and incredibly effective compared to pumped storage or batteries.

Disagree. Batteries and a synchronous induction motor are far, far lower tech than a modern Diesel engine. We have a lot of spare transmission capability on our grid - at night when most cars are parked. Electric cars, smart grids, storage, it's three for the price of one.

> PS if you were going to design a fantasy energy system it would be taking CO2 from air to make a fuel that has market and can be used to store energy until it is needed when there is no wind/sun/other renewable generation.

Well, I'd take it from the exhaust of fossil or biomass burning plant, far less energy to extract it.

Like I said earlier, I'd do it with methane and the gas grid, not synthetic heavy oils. Edit: I believe Audi are piloting the methane approach in Germany as well.
Post edited at 00:16
elsewhere on 17 Sep 2016
In reply to wintertree:
Good points, although I reckon a manufacturing a steel tank to hold deisel is far cheaper and greener than manufacturing the equivalent battery storage (or compressing and refrigerating methane).

Smart grids and distributed energy storage in car or home batteries might be a long way into the future compared to deisel tanks and deisel power stations or fueling deisel cars.

Post edited at 09:48
1
wintertree - on 17 Sep 2016
In reply to elsewhere:

> Good points, although I reckon a manufacturing a steel tank to hold deisel is far cheaper and greener than manufacturing the equivalent battery storage (or compressing and refrigerating methane).

Yes, although assuming lithium batteries can be remanifactured once - I.e. used twice - the total system is greener with lithium than with diesel.

> Smart grids and distributed energy storage in car or home batteries might be a long way into the future compared to deisel tanks and deisel power stations or fueling deisel cars.

The same could be said about industrial scale production infrastructure for synthetic diesel - I'd rather see the money spent building an internal combustion future future. Quite asside from the overall energy efficiency there is the air pollution issue as well.

Electric cars are becoming more prevalent - in the first instance "smart grid" could just mean charging at night.
1
summo on 17 Sep 2016
In reply to elsewhere:
> PS if you were going to design a fantasy energy system it would be taking CO2 from air to make a fuel that has market and can be used to store energy until it is needed when there is no wind/sun/other renewable generation.

I think it is called wood.
elsewhere on 17 Sep 2016
In reply to wintertree:
A battery for a few or ten thousand pounds stores less than five pounds worth of electricity so storage of more than 24hrs of domestic consumption is uneconomic. The battery costs about a thousand times what it stores.

A domestic heating oil tank costing a thousand pounds stores a few hundred pounds worth of heating oil which is economic for weeks or months of consumption. The tank is far cheaper than a battery and the energy storage is far greater. The tank costs a few times what its stores.

Diesel would be a brilliant way of storing electricity because the storage costs (Joules per £) are so good.

A wood stack or coal heap is even better. The costs of a tarpaulin, axe, shovel etc are modest and again you can store enough for weeks or months of consumption. The cost of stacking or heaping is far less than the cost of the energy it contains.
elsewhere on 17 Sep 2016
In reply to summo:

> I think it is called wood.

If you have the land this is a very good option.
wintertree - on 17 Sep 2016
In reply to elsewhere:
You're missing a few points here.

An oil tank, a tarp, a wood heap. Great if you live in the country; more than 50% of people in the UK now live on towns and cities, that percentage is rising. Besides heating is becoming less important with insulation - it's insane in the modern world to spend much energy heating a property.

Domestic batteries - a potential part of the solution to erratic renewables. You get these for free with electric cars; most cars have far more range than most car owners need almost all the time. So when you're not planning a long journey 20% of the range gets set aside for renewable buffering, perhaps simply by only charging the last 20% at times of excess renewables; this way you don't even cycle the battery more or suffer bidirectional conversion losses.

Battery costs are going down.

I've nothing against hydrocarbon synthesis as part of a renewals solution but make it light gasses not diesel.

Oil burning - especially in engines - is a large contributor to the circa 8,000,000 premature deaths worldwide due to air pollution.

I maintain diesel is a crap way of storing electricity. Your round trip efficiency is appalling, circa 35%. You cost up batteries but omit the cost of a diesel generator and it's consumables. Filthy pollution. Large scale energy storage in the gas grid and through smart charging of grid connected electric vehicles. Better efficiency and far less air pollution.
Post edited at 16:57
2
elsewhere on 17 Sep 2016
In reply to wintertree:
The oil tank or wood heap can be at the power station, the storage can hold weeks or months worth of consumption and costs bugger all compared to a battery that won't last 24 hours of consumption.

Diesel is a bloody awful fuel in cities but it also works for gas turbines generators so may even work in the existing natural gas powered power stations.
Post edited at 21:17
wintertree - on 17 Sep 2016
In reply to elsewhere:

> The oil tank or wood heap can be at the power station,

How the hell are you going to turn synthetic diesel into wood?

> the storage can hold weeks or months worth of consumption and costs bugger all compared to a battery that won't last 24 hours of consumption

If someone has a Tesla Model-S it stores about 400 hours of consumption. A Nissan Leaf is about 120 hours. You might want to revisit your assumptions. That's plenty of spare capacity for most people to soak up renewables in times of excess, with over 3x the efficiency of going via synthetic diesel and back.

> Diesel is a bloody awful fuel in cities but it also works for gas turbines generators so may even work in the existing natural gas powered power stations.

I don't believe the current CCGT plants run on kerosene/diesel. They do run on methane. All the oil burning plants are gone/mothballed and anyway were not turbines. Methane burns far more cleanly than heavy oils in a turbine - important for achieving the constant power output over weeks and low maintenance required for a power plant.

I can stomach the idea of synthesising methane with excess renewables as using it requires literally no new infrastructure to use it for power and heating, and it's quite clean burning. The same things can't be said for synthetic diesel.
Post edited at 22:34
summo on 18 Sep 2016
In reply to elsewhere:

> If you have the land this is a very good option.

you get rid of the national parks upland management policy and reforest. You build with the good wood, locking in carbon for centuries, you burn the off cuts and low quality stuff as biomass for communal(city wide) heating and electricity generation.
elsewhere on 18 Sep 2016
In reply to wintertree:
> How the hell are you going to turn synthetic diesel into wood?

Why would anybody think that is required to generate electricity from deisel?

> If someone has a Tesla Model-S it stores about 400 hours of consumption. A Nissan Leaf is about 120 hours.

Domestic power consumption costs a 3-5 pounds per day. If a car stores 400 hours of consumption that is 16 days worth and that implies it costs 50 to 80 quid per charge.
Your numbers don't sound right.

Checking online tesla s battery is 60kwh and domestic consumption is 10000 kwh per year so the expensive battery runs out in 2 days.
In contrast it is economic to store enough chemical energy to cover consumption for weeks and months.



Baron Weasel - on 18 Sep 2016
In reply to summo:
> you get rid of the national parks upland management policy and reforest. You build with the good wood, locking in carbon for centuries, you burn the off cuts and low quality stuff as biomass for communal(city wide) heating and electricity generation.

You have my vote for this - can we plant orchards too so that we can all make cider?
Post edited at 13:42
wintertree - on 18 Sep 2016
In reply to elsewhere:

> Why would anybody think that is required to generate electricity from diesel?

I don't know. You're the one who was talking about a wood heap.

> Checking online tesla s battery is 60kwh and domestic consumption is 10000 kwh per year so the expensive battery runs out in 2 days.

UK domestic electricity consumption is between 5 kwh/day and 12 kwh/day. Teslas come with between 60 kWh and 100 kWh of storage. So between 5 and 20 days of storage.

I'm not counting heating consumption because wasting 50%+ of renewable energy going electricity > oil > heat is so fundamentally dumb nobody would suggest it. Better insulation.

> In contrast it is economic to store enough chemical energy to cover consumption for weeks and months.

Not so economic when the round trip efficiency of your chemic storage maxes out at 35% and is nudging 90% with batteries. It's also ignoring the massive air pollution issues associated with burning diesel. As I keep saying methane makes more sense than diesel as a way of buffering renewables.

Electric cars are rolling out in ever increasing numbers already. Simply reserving a small fraction of their range for charging only in times of excess renewables cane make this a more or less solved problem now - and assuming electric cars continue to increase at the same pace as renewable increase then the problems is solved going forwards without the frankly dumb and stupid idea of synthesising and then burning heavy oils from renewable electricity. As it is electric cars are increasing in number far faster than renewable deployment.

We burn oil form the ground and accept the thermodynamic losses because we don't have a better way of converting the energy. Accepting those losses and more with electricity > oil > electricity is fundamentally stupid. Especially when there is no pressing need for the "solution" that it would enable.


In reply to wintertree:
> Oil burning - especially in engines - is a large contributor to the circa 8,000,000 premature deaths worldwide due to air pollution.

Wouldn't this synthetic diesel burn cleaner since it doesn't have a lot of the nasties in it?

I've just re-read the article and it answered my question

> it does "not contain sulfur or aromatics and burns without producing any soot"
Post edited at 09:29
wintertree - on 19 Sep 2016
In reply to Paul Phillips - UKC and UKH:

> Wouldn't this synthetic diesel burn cleaner since it doesn't have a lot of the nasties in it?

> I've just re-read the article and it answered my question

It will burn cleaner (soot and particulates) than the stuff from forecourts but I don't see how the NOx production will change - that's a result of the combustion process combined with atmospheric air, not the fuel content.

I'm also not sure how much credibility Audi currently have when it comes to stating emmisions data...
Post edited at 10:00
In reply to wintertree:

> I'm also not sure how much credibility Audi currently have when it comes to stating emissions data...

True
jkarran - on 19 Sep 2016
In reply to wintertree:
I'm with you on this re. electric cars, they are potentially the solution to several problems in one quite appealing package but for it to work well business and government really need to up their game if we're to realise the full potential benefits.

Synthetic diesel for the road is basically greenwash for Audi. Perhaps synthetic liquid hydrocarbon fuel is a partial solution to powering marine and air traffic but I suspect long term the biggest carbon savings in that area will be deceptively low tech: moving less stuff less far and better use of the wind.
jk
Post edited at 13:43
Martin W on 19 Sep 2016
In reply to wintertree:

> I'm also not sure how much credibility Audi currently have when it comes to stating emmisions data...

Or anyone else, for that matter:

https://www.theguardian.com/technology/2016/sep/19/many-car-brands-emit-more-pollution-than-volkswag...

(Should come as no surprise to those who always believed that "they're all at it" - even before 'dieselgate' happened).
jimtitt - on 19 Sep 2016
In reply to wintertree:

Hmm, leaving aside how long Tesla can keep producing cars at their current rate of losses, how much lithium is available, how difficult and expensive it is to store methane and all those things I´ m just pondering on exactly how big a battery pack you need for a 44 ton truck or a 200hp tractor. I think you´ ve forgotten about a few branches of the transport industry as well as stuff like heavy plant who are reliant on diesel fuel and will be for the foreseable future.
wintertree - on 19 Sep 2016
In reply to jimtitt:

> how expensive it is to store methane

Crap for two reasons. 1 - methane storage isn't that expensive and the infrastructure is already here on an industrial scale with both liquified and and compressed gas plants. 2 - cost of storage alone is irrelevant - the overal system cost matters including production and efficiency losses.

> I think you'be forgotten about a few branches of the transport industry as well as stuff like heavy plant who are reliant on diesel fuel and will be for the foreseable future.

I've not forgotten about any of them.

There is no shortage of diesel from the ground. Until there is a shortage and with a mixed fleet of diesel and electric vehicles, it wastes more fossil fuels to use renewable>diesel synthesis for renewables buffering than it does to use renewable>electric car.

You don't need a full fleet of electric cars to realise an excess renewables > EV based storage system. Even with a relatively small fleet this is a far less stupid idea than renewables > synthetic diesel > electricity. Edit: The less efficient your renewable buffering, the more fossil fuel you have to burn in a mixed fossil/renewable system.

If we were discussing a world without fossil diesel then it might have more merit. Discussions here have been about buffering renewable energy, for which diesel is crap.

I make no comment one way or the other about the viability of replacing all diesel vehicles with electric ones. Irrelevant to this discussion to date. Nobody has as far as I can see proposed running all diesel vehicles from renewable synthesised diesel.
Post edited at 14:54
wintertree - on 19 Sep 2016
In reply to jkarran:

> Perhaps synthetic liquid hydrocarbon fuel is a partial solution to powering marine and air traffic

It could also be very interesting for reusable rocketry if it reduces coking and polymerisation which Audi's claims suggest. That might also make it a superior fuel for low bypass military jets. Rocket people are tending to look to methane instead.

jimtitt - on 19 Sep 2016
In reply to wintertree:

Sorry, thought it was a general discussion about the merits of being able to produce an easily transportable, high energy density fuel from renewable energy which is essential to the transport and other industries.
wintertree - on 19 Sep 2016
In reply to jimtitt:

> Sorry, thought it was a general discussion about the merits of being able to produce an easily transportable, high energy density fuel from renewable energy which is essential to the transport and other industries.

Not that I've seen anywhere on this thread at all...

My hope is that the ongoing improvements in battery resource requirements, energy storage density and cost will make the electric option viable for almost all ground based vehicles before the availability of oil becomes an issue.

Over the timescales this becomes important: (1) I'm not so sure that diesel is "essential" or desirable. There are other liquid-at-STP hydrocarbons that would likely be preferably to diesel in terms of NOx production in combustion engines, and (2) fuel cell technology will likely take over from combustion engines and will probably prefer lighter hydrocarbons.



elsewhere on 19 Sep 2016
In reply to wintertree:
> UK domestic electricity consumption is between 5 kwh/day and 12 kwh/day. Teslas come with between 60 kWh and 100 kWh of storage. So between 5 and 20 days of storage.

A Tesla car can power a house for 5 to 20 days.

But you have to give up driving. And you can't have any heating*. And you have no hot water. For 5 to 20 days.

Batteries costing thousands of pounds per household can and do smooth out daily mismatches in supply and demand.

Batteries costing thousands of pounds per household can't smooth out seasonal mismatches in supply and demand when you need a month of heating in three months time.

*a super insulated house can do without heating, but good luck with achieving that standard by adding >30cm of insulation to the exterior or interior of existing housing along with new windows and a heat exchanger for the ventilation system.





elsewhere on 19 Sep 2016
In reply to jimtitt:
> Sorry, thought it was a general discussion about the merits of being able to produce an easily transportable, high energy density fuel from renewable energy which is essential to the transport and other industries.

And could be stored until winter for use as a renewable heating oil
Post edited at 15:23
1
summo on 19 Sep 2016
In reply to elsewhere:

> *a super insulated house can do without heating, but good luck with achieving that standard by adding >30cm of insulation to the exterior or interior of existing housing along with new windows and a heat exchanger for the ventilation system.

True, ish. There is no reason why current building specs can't be lift to included a substantial amount ground insulation before building. The more desirable 400mm in roof spaces. And double layer insulation on walls to prevent bridging, with materials available you don't specifically need 30cm now, it's more down to how it's layered and the wall is constructed. Then you've just got doors and windows to sort out. Part of the problem is housedesign and layout, lots of pokey little rooms to advertise 4 bed, dining room, micro garage, office space etc.. rather than more open plan which is much easier to heat.

After that air source heat pumps, communal ground source and biomass boilers. You could get pretty close to carbon neutral (apart from the construction and installation of the materials themselves) and certainly more efficient than putting boilers in every house and wet pipe systems.
jimtitt - on 19 Sep 2016
In reply to wintertree:

> Not that I've seen anywhere on this thread at all...

Err, the original article from Audi?

We´ ve looked into energy storage and methane storage because where my workshop is sited is a biomass generating plant and we are used as a renewable buffer for the other crap systems like wind which barely works and solar which often doesn´ t. We get extra payment for more flexible power production but after about 8 hours shut down we have to start burning off gas, even at the ludicrous rates the Germans pay for power there´´ s no economic way to either store the power or the gas. It´ s not even feasible compressing the methane and using it in the tractors and that is a simple proven technology suitable for small scale operations.


Toerag - on 19 Sep 2016
In reply to summo:
> Part of the problem is housedesign and layout, lots of pokey little rooms to advertise 4 bed, dining room, micro garage, office space etc.. rather than more open plan which is much easier to heat.

It might be 'easier' to heat open spaces, but it's costlier and wasteful - why heat a massive room when you only need to heat the small one you're in?

> After that air source heat pumps, communal ground source and biomass boilers. You could get pretty close to carbon neutral (apart from the construction and installation of the materials themselves) and certainly more efficient than putting boilers in every house and wet pipe systems.

Yep, heat pumps are the way forward and it's noticeable how many are being installed nowadays.
jkarran - on 19 Sep 2016
In reply to jimtitt:

The uk already has quite a bit of gas storage, both LNG and compressed gas stored underground. Might not be quite the same situation as you're facing (presumably a capped rubbish dump with compressor, tank and a generator set?).
jk
summo on 19 Sep 2016
In reply to Toerag:
> It might be 'easier' to heat open spaces, but it's costlier and wasteful - why heat a massive room when you only need to heat the small one you're in?

That's only if you are obsessing with wet pipe radiators on walls. Open spaces work perfectly with air / ground sourced heat pumps / exchangers, or / and under floor heating. . Every door or wall is an obstacle to air movement. Also better for light, less corners and shadows, more natural light.
Post edited at 16:29
Toerag - on 19 Sep 2016
In reply to jimtitt:

> I´ m just pondering on exactly how big a battery pack you need for a 44 ton truck or a 200hp tractor.
It's obviously been thought about:-
http://spectrum.ieee.org/cars-that-think/transportation/advanced-cars/electric-truck-startup-nikola-...

Electric trucks will happen because of 'clean air' regulations in cities, and of course the benefits of high torque electric motors for moving heavy things.


wintertree - on 19 Sep 2016
In reply to elsewhere:

> A Tesla car can power a house for 5 to 20 days.

> But you have to give up driving. And you can't have any heating*. And you have no hot water. For 5 to 20 days.

If you can't read more than one of my messages at a time we either need to give up this conversation or I need to repeat everything every time.

You'll note I repeatedly suggesting using a fraction of "spare" range in a car battery to soak up excess renewables at time of excess for later use, not to buffer central heating...

Giving up on heating is the idea - it's crazy to burn energy actively heating houses. Cheaper in the long run to insulate better. That's where modern houses now are, and what is happening to older houses.

> Batteries costing thousands of pounds per household can and do smooth out daily mismatches in supply and demand.

> Batteries costing thousands of pounds per household can't smooth out seasonal mismatches in supply and demand when you need a month of heating in three months time.

See earlier posts and comments on heating.

> *a super insulated house can do without heating, but good luck with achieving that standard by adding >30cm of insulation to the exterior or interior of existing housing along with new windows and a heat exchanger for the ventilation system.

Yes, that's the idea. It's what we're doing gradually with our centuries old dales farmhouse, along with digging up the floors and putting in high thermal mass and heavily insulated sub-floors and counter current heat exchanging ventilation.

We can't afford the environmental costs of heat loosing housing - in the real world for the next decade or two or more renewables offset fossil fuels so it doesn't matter how green the energy wasted by a house is, it ultimately corresponds to fossil fuel burning.

In the real world the problem is not running 3 months of winter off excess Autumn renewables as you paint it. There are far, far bigger problems to that plan than the choice of storage... By the time distributed renewable generation is at a scale it can handle this 20-50 years will have passed, and batteries and the housing stock will have changed a lot, as will distribution of EVs.

Diesel burning combustion engines will still suck in 50 years time. I'd stake money on it. So would the laws of thermodynamics.



wintertree - on 19 Sep 2016
In reply to jimtitt:

> Err, the original article from Audi?

No. It said literally nothing about moving to a world with near current diesel usage enabled by their synthetic diesel production,

> We´ ve looked into energy storage and methane storage because where my workshop is sited is a biomass generating plant and we are used as a renewable buffer for the other crap systems like wind which barely works and solar which often doesn´ t. We get extra payment for more flexible power production but after about 8 hours shut down we have to start burning off gas, even at the ludicrous rates the Germans pay for power there´´ s no economic way to either store the power or the gas. It´ s not even feasible compressing the methane and using it in the tractors and that is a simple proven technology suitable for small scale operations.

The cost of liquifcarion drops with larger scale plants; I beleive the idea would be for outfits such as yours to inject the methane into the gas grid, in the first instance offsetting fossil gas usage and in the second feeding into grid connected liquifaction plants.

This needs investment in the gas grid however. Well worth doing as - for now - methane synthesis is a far better renewable buffer than diesel in terms of air pollution and overall efficiency.

More smart appliances would also help soak up the power - fridges and freezers that cool 5oC more in times of excess renewables, electric cars that reserve charging capacity for times of excess etc.

I doubt a diesel synthesis plant would be any more economical at the scale you work on than any methane liquifaction options etc.

These are complex systems level problems; Audi's desire to greenwash their credentials as they try and get the most out of their investment in a fundamentally crap technology is not a good part of the solution.
jimtitt - on 19 Sep 2016
In reply to wintertree:
> No. It said literally nothing about moving to a world with near current diesel usage enabled by their synthetic diesel production,

Ah well, I did say the original article which appeared a few years ago (the British media seems to be a few years behind somehow) where Audi wrote "Die Stuttgarter Forscher sagen voraus, dass Blue Crude nicht nur den Fernverkehr von Autos, sondern auch den Flugverkehr umweltfreundlicher machen k£nnte." Which translated means that Blue Crude could not only make long-distance transport but also air transport environmentally friendlier.
The photo in the OP£ s linked article is of German Environment minister beside an Audi, in the article from Engineer.de she is shown filling the car.
Post edited at 18:50
jimtitt - on 19 Sep 2016
In reply to jkarran:

> The uk already has quite a bit of gas storage, both LNG and compressed gas stored underground. Might not be quite the same situation as you're facing (presumably a capped rubbish dump with compressor, tank and a generator set?).

> jk

Good lord , we don´ t mess about with rubbish tips! The guys plant stuff, harvest and silage it then it goes into a digester then a fermenter and the happy bacteria make methane, bit over 100m³/hr at full blast if I remember rightly.
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