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Rotary engines have been in use for quite a while now, popular on ski-jets I believe! Past ones have had a reputation for eating seals if over-revved, but the beauty of the Rex approach is that you can't thrash the engine, even if you really want to! So Mazda should be able to operate it at a decently optimal speed, compression ratio etc etc.

And if the Rex gets v unreliable & dies, just drive it as a normal modest-range Ev! I have a plan B for that already! :)
 

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It's fairly green in that it's 100% recyclable.
Its not green if it uses vast amounts of electricity to create and recycle


But at 7p per kWh and potentally 10% lost due to early swap out you're looking at petrol costs.
My solution would be to have two or more batteries and swap one when it's drained.
Or 5 then refull 80% on a charge/swap(hmmm where have I heard that before)
The story i read said 7p per MILE not kWh. SO about 4x your estimate :D
 

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Its not green if it uses vast amounts of electricity to create and recycle
Not so if it uses the vast overkill of excess wind turbines that are needed for lulls in the wind.

We'll need 10 times the amount of wind power than generating requirement, so that 'spare' 90% could be used when the wind is blowing strongly to do all the storage/recycling things to be done, in time for when wind stops blowing.
 

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that 'spare' 90% could be used when the wind is blowing strongly to do all the storage/recycling things to be done, in time for when wind stops blowing.
I do wonder if the various organisations involved would really be capable of making that work. It's a big ask in that the recyclers would be wasting a lot of production time idle while waiting for the right kind of wind.
 

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I do wonder if the various organisations involved would really be capable of making that work. It's a big ask in that the recyclers would be wasting a lot of production time idle while waiting for the right kind of wind.
Remember that hydro can be used as a buffer, so you start up the plant when there is too much wind and all batteries are charged, but only shut it down when both the wind has stopped and the hydro is low. Maybe the recover plant can just be a normal aluminium production plant.
 

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There's a new energy storage system being planned here in UK, and it will use liquid air as the operating fluid. I assume the idea is to let it expand hugely by warming it from atmospheric air (free), and using the volumetric expansion to drive turbines.
https://www.energylivenews.com/2019/10/22/highview-power-to-launch-uks-first-large-scale-cryogenic-energy-storage-plant/
Add that to the potential for V2G, and with luck there will be plenty of energy storage around to mop up the peaks of production.
 

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Remember that hydro can be used as a buffer, so you start up the plant when there is too much wind and all batteries are charged, but only shut it down when both the wind has stopped and the hydro is low. Maybe the recover plant can just be a normal aluminium production plant.
the max output for Hydro in the UK is around 2% and new hydro schemes are no longer considered to be green due to loss of habitat, its unlikely that there will be (m)any new ones, so theres still a lot of electrons left going begging.....
 

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Not so if it uses the vast overkill of excess wind turbines that are needed for lulls in the wind.

We'll need 10 times the amount of wind power than generating requirement, so that 'spare' 90% could be used when the wind is blowing strongly to do all the storage/recycling things to be done, in time for when wind stops blowing.
There are many better ways of storing electricity than smelting and transporting aluminum.
Where do you get the 10x figure from anyway?
 

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Reports on wind power. About a 1/3rd of the time it only puts out 10% of the rated power, ergo you need 10x more than needed as rated power.

What other energy storage do you propose then? Don't forget total system efficiency .. once the al is made there is no real loss of efficiency then up to delivery to the wheels.
 

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Seems to me we could forget car use - just build a battery driven power station paired with an aluminium plant. Connected by a conveyor belt :)
 

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Where do you get the 10x figure from anyway
They start by assuming gas/oil will be not used at all, eg all energy from electricity.

I think it then comes was the relative cost of storing many weeks electricity requirements for many weeks compared to having enough wind generation that there is no need for long term storage. (Batteries are assumed in both cases to cope with times of day that have peak demand.)

However if we assumed we will keep the gas grid, it is possible to make LPG from excess electricity (var hydrogen) and LPG is easy to store.
 

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Reports on wind power. About a 1/3rd of the time it only puts out 10% of the rated power, ergo you need 10x more than needed as rated power.

What other energy storage do you propose then? Don't forget total system efficiency .. once the al is made there is no real loss of efficiency then up to delivery to the wheels.
Donald, if the main storage / buffering mechanism for renewable ever essentially consists of smelting and then re melting Al , I will personally come up to Scotland and buy you a very nice meal. No time limit except whoever pops their clogs first.
 

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Donald, if the main storage / buffering mechanism for renewable ever essentially consists of smelting and then re melting Al , I will personally come up to Scotland and buy you a very nice meal. No time limit except whoever pops their clogs first.
Fair 'nuf. I like one sided bets! ;)

Thing is, it doesn't have to be 'all' of such storage, just added to the mix for the general betterment of everyone.

I did calculations on the amount of land required for various power generation and storage options, and it doesn't really look very feasible. Al would, at least, be very energy dense and easy to store. The overall efficiency doesn't have to be great, so long as it is practical and feasible.

You could stack al sheets in one of those massive anonymous warehouses you already barely notice on the side of a motorway for the same land usage as several Dinorwigs, for a given energy storage. Those sheets could sit there for years, in perfectly stable and safe conditions. Minimal risk of fires, zero of explosions, no pressurised or cooled systems to keep active. Just lock the door and wait until it is needed.
 

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There's a new energy storage system being planned here in UK, and it will use liquid air as the operating fluid. I assume the idea is to let it expand hugely by warming it from atmospheric air (free), and using the volumetric expansion to drive turbines.
https://www.energylivenews.com/2019/10/22/highview-power-to-launch-uks-first-large-scale-cryogenic-energy-storage-plant/
Add that to the potential for V2G, and with luck there will be plenty of energy storage around to mop up the peaks of production.
This is looking very interesting at 11p per kwh vs the 13-20p per kWh Al seems to work out at*

( 7p mile @ 5 mpkwh = 35p/kwh or 15p+20p storage cost)
(7p mile @ 4 mpkwh = 28p/kwh or 15p+ 13p storage cost)
 

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It takes sooooo much energy to make batteries. Using them once and throwing them away is always a bad idea. Reduce - reuse - recycle. I would rather have a rex than a throwaway backup battery.
 

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It takes sooooo much energy to make batteries. Using them once and throwing them away is always a bad idea. Reduce - reuse - recycle. I would rather have a rex than a throwaway backup battery.
Depends what sort of battery.

That is far too a generalised throw-away line that it makes no sense.
 
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