Porsche E-Fuel?
Discussion
"No pollution"? er no.
Yes, Synthetic fuels could provide some solution to applications that MUST have an energy storage system with a high specific density (ie aeroplanes for example) and if that fuel is synthesised from a low carbon source (carbon capture for example, or bio-produce) then that fuel does have a lower impact that using a fossil fuel. But it is NOT zero pollution and it remains significantly higher overall polluter because of the intrinsically low thermal/mechanical efficiency and mono-directionality of the energy to power conversion process (Reciprocating piston engine or jet engine for example), which no matter how you run it, is incapable of "filling the tank back up" as you slow down!
This is much less of an issue for aircraft, which already recover 100% of their potential energy by dint of simply gliding (exchanging potential energy for kinetic) and tend to fly at a reasonably constant speed so the only kinetic energy they loose is mostly that converted to heat in the brakes on landing (The vast majority of the energy is used to simply overcome drag). And a modern jet engine is pretty efficient for a heat engine.
This is why i think we will see a demand for sythetic fuels for aviation, that means they are simply not available for the bulk of passenger car useage. Yes, you will almost certainly in 2121 be able to keep that classic, 100 year old porsche 992 series 911 on the road with some costly specially purchased sythetic petrol, but that will be as much an exception as those people putting coal into their Steam Traction Engine is today!
Yes, Synthetic fuels could provide some solution to applications that MUST have an energy storage system with a high specific density (ie aeroplanes for example) and if that fuel is synthesised from a low carbon source (carbon capture for example, or bio-produce) then that fuel does have a lower impact that using a fossil fuel. But it is NOT zero pollution and it remains significantly higher overall polluter because of the intrinsically low thermal/mechanical efficiency and mono-directionality of the energy to power conversion process (Reciprocating piston engine or jet engine for example), which no matter how you run it, is incapable of "filling the tank back up" as you slow down!
This is much less of an issue for aircraft, which already recover 100% of their potential energy by dint of simply gliding (exchanging potential energy for kinetic) and tend to fly at a reasonably constant speed so the only kinetic energy they loose is mostly that converted to heat in the brakes on landing (The vast majority of the energy is used to simply overcome drag). And a modern jet engine is pretty efficient for a heat engine.
This is why i think we will see a demand for sythetic fuels for aviation, that means they are simply not available for the bulk of passenger car useage. Yes, you will almost certainly in 2121 be able to keep that classic, 100 year old porsche 992 series 911 on the road with some costly specially purchased sythetic petrol, but that will be as much an exception as those people putting coal into their Steam Traction Engine is today!
NDNDNDND said:
The bit that Max conveniently ignores is that SHCF negates the requirement for a hugely carbon-intensive battery to be manufactured. It'll be interesting, for instance, to see how many Lotus Evija get driven far enough to offset their embodied carbon dioxide and, if they do, quite how many years it takes...
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er, i'm not conviently "ignoring" anything..
Facts:
1) Battery manufacture is not fundamentally "high carbon". In fact, being a mainly low temperature process that only requires low powers and process it is fundamentally a LOW carbon solution. Today, current battry manifacture is (eroneously) generally called high carbon simply because the manufacturing processes are not powered by renewables (they can easily be done so, because unlike say an electric arc furnace requied to melt metal, they do not require many MW worth of power) and because the limited geographic locations of the manufacturing sites and limited geographic locations of the raw materal sites are not co-located. As recycling of the battery materials becomes more prevalent, the overheads from battery manifacture fall dramatically (remember a battery does NOT consume the materials from which it is made!, so recycling is very viable (just like it is with the conventional lead acid battery that's been in your car for over 100 years now)
2) The efficiency of the end user, in terms of kWh per mile is critical, because this is what is then leveraged through the "gain" of the system of manufactuer and supply to the OVERALL energy consumption. So even if batteries were higher carbon (and i'm going to suggest that they are not) then using an ICE to burn a sythetic fuel is catastrophically weighted by the fact the end user requires around 3 to 4 times more energy for the same useage, and so ultimately, irrespective of the process by which that energy is managed, the final overhead will be greater. Sythetic fuels are not bi-directional, an engine runing such a fuel cannot fill the tank back up when it slows down, unlike for a electric traction motor and battery. In the real world, this penalty is enormous abnd inescapable.
You mention a niche case like the Lotus Evija, which is irrelavent, as i could simply mention any number of ICE powered super cars all of which have a massively higher footprint (like oh a Ferrari 812 superfast, which has an offical fuel 'economy' of 19 mpg (340 g/km)!!! And of course, if you wanted too, you could simply scrap your brand new Evija and use it's battery in a second life application straight away (or after you bin it into a lamppost) and effectively negate it's overhead that way!
Like Hydrogen, synthetic fuels have their place but it's not in passenger cars........
jjwilde said:
E-Fuel sounds even worse than hydrogen.
It has a significant advantage in that as a reasonably low volitility liquid, an E-FUEL mainly just sits in the bucket you poured it into, rather than trying to escape BETWEEN the molecules of the container its in, or needing to be compressed, chilled, or captured by some clever material in order to simply not float away into space!Gassing Station | EV and Alternative Fuels | Top of Page | What's New | My Stuff