How much Fossil Fuel to Travel 200 Miles in a Model S?
Discussion
Also of note, is that the grid Carbon intensity caries across the country and throughout the day and throughout the seasons.
An EV charged in the evening could be consuming 200-300gCO2/kWh. But at night that can easily drop below 100gCO2/kWh.
Similarly the efficiency consumption of the EV at the plug can vary based on factors such as charge rate and pre-conditioning, as you could use 10% of your daily propulsion (10kWh) just getting the car war and comfortable in the morning. It's a nice trick, but it does play it's part.
So really, before anyone throws down a conclusion, the assumptions need to be agreed and even then there's a massive upper and lower limit.
An EV charged in the evening could be consuming 200-300gCO2/kWh. But at night that can easily drop below 100gCO2/kWh.
Similarly the efficiency consumption of the EV at the plug can vary based on factors such as charge rate and pre-conditioning, as you could use 10% of your daily propulsion (10kWh) just getting the car war and comfortable in the morning. It's a nice trick, but it does play it's part.
So really, before anyone throws down a conclusion, the assumptions need to be agreed and even then there's a massive upper and lower limit.
JonnyVTEC said:
Don't forget when you square the power in terms of roadload you can't do the same for the consumption as the car is covering more distance in the same time period.
I'm not understanding what you mean by "square the power in terms of roadload".In relation to speed:
- The power to overcome rolling resistance increases linearly.
- The power to overcome drag increase with a CUBE law.
But because a higher speed means less time per mile, linearly, then the relationships of energy-per-mile are:
- Tyre rolling resistance simplistically has a fixed energy-per-mile relationship to speed.
- Aerodynamic drag has a square law energy-per-mile relationship to speed.
The typical crossover point where the magnitude of power to overcome drag exceeds rolling resistance is around 50 mph.
politeperson said:
Finally, how much extra embodied energy is used in the production of an EV over the equivalent ICE car?
I would love to know the truth. It seems like a very complicated pair of questions though.
Sonemone must be able to put me right?
Not sure where but saw an interview with the head of polestar awhile ago and he implied it took the equivalent of 48k miles extra to build an ev over ice (last figure I remember for an ice was that it took approx 150k miles in a vehicle before more had come out of the tailpipe than the manufacturer had used to build the thing).I would love to know the truth. It seems like a very complicated pair of questions though.
Sonemone must be able to put me right?
It’s not just making the vehicle though, it is the transport of said vehicle and parts around the globe that is also an issue.
The build cost obviously depends massively on the car in question, but even ig you pick a single car which is available as both EV and ICE it's an extremely complex question because there's always the question of "what do you include?".
For BEVs you presumably have to include the cost of finding and extracting the Lithium, but then that means for ICE you need to include the cost of finding and extracting platinum for the cat, iridium for the spark plugs, etc. which, whilst lower than the environmental cost of extracting enough Lithium, is still very significant and somehow is never included in the figures for ICE vehicles.
Smelting steel is also a horrifically environmentally damaging process, involving burning huge quantities of coal. That's probably similar for both cars but whether you include it or not will significantly skew the proportional difference in cost.
ETA: I think there's a few things which can be said categorically though:
1) Making new things is bad
2) Making new cars is very bad
3) If you have to make new cars, over their lifetime EVs are considerably less bad than ICE vehicles. How much less bad depends on the car and, more importantly, on the way the electricity used to power it is generated.
4) Pretty much everywhere in the world, electricity generation is getting "greener" so if you buy an EV now your emissions per mile will fall over its lifetime.
5) The UK's power generation is already pretty low carbon, making the CO2 pay-back time for EVs here considerably lower than in much of the world.
For BEVs you presumably have to include the cost of finding and extracting the Lithium, but then that means for ICE you need to include the cost of finding and extracting platinum for the cat, iridium for the spark plugs, etc. which, whilst lower than the environmental cost of extracting enough Lithium, is still very significant and somehow is never included in the figures for ICE vehicles.
Smelting steel is also a horrifically environmentally damaging process, involving burning huge quantities of coal. That's probably similar for both cars but whether you include it or not will significantly skew the proportional difference in cost.
ETA: I think there's a few things which can be said categorically though:
1) Making new things is bad
2) Making new cars is very bad
3) If you have to make new cars, over their lifetime EVs are considerably less bad than ICE vehicles. How much less bad depends on the car and, more importantly, on the way the electricity used to power it is generated.
4) Pretty much everywhere in the world, electricity generation is getting "greener" so if you buy an EV now your emissions per mile will fall over its lifetime.
5) The UK's power generation is already pretty low carbon, making the CO2 pay-back time for EVs here considerably lower than in much of the world.
Edited by kambites on Thursday 2nd December 10:29
Ardennes92 said:
politeperson said:
Finally, how much extra embodied energy is used in the production of an EV over the equivalent ICE car?
I would love to know the truth. It seems like a very complicated pair of questions though.
Sonemone must be able to put me right?
Not sure where but saw an interview with the head of polestar awhile ago and he implied it took the equivalent of 48k miles extra to build an ev over ice (last figure I remember for an ice was that it took approx 150k miles in a vehicle before more had come out of the tailpipe than the manufacturer had used to build the thing).I would love to know the truth. It seems like a very complicated pair of questions though.
Sonemone must be able to put me right?
It’s not just making the vehicle though, it is the transport of said vehicle and parts around the globe that is also an issue.
It's 48,000 miles in total before an EV has lower lifetime pollution than and ICE.
kambites said:
But then to make that a fair comparison, you can't only look at the tailpipe emissions of the ICE you're comparing to, you need to take into account the electricity used to refine the petrol (the natural gas used to generate electricity doesn't require significant refinement) - about 5kwh per gallon. So if your car does 40mpg, that's an extra 5kwh per 40 miles for the petrol car; which is 125wh/mile which at the above is about 30g/km to refine the petrol. So if your 40mpg petrol car is about 160g/km at the tailpipe, or about 190g/km including refinement.
you should also take into account the extraction of the oil, shipping it (a very high pollution source) and transporting from the refinery to the fuel stationyou also need to account for huge amount of cobalt used in oil refining (mining and shipping) and any other catalyst used in oil refining (zeolite, aluminum hydrosilicate, bauxite and silica-alumina?)
and if your really doing it properly all the maintenance items and consumables for all of the above equipment and its support equipment (such as brakes, oil and tyres on petrol tankers).
if i recall correctly uk refineries use enough electricity to charge 14 million EVs once a week every week of the year
Edited by Dave Hedgehog on Thursday 2nd December 13:18
Dave Hedgehog said:
if i recall correctly uk refineries use enough electricity to charge 14 million EVs once a week every week of the year
Quite a lot of information here :- https://greentransportation.info/energy-transporta...Edited by Dave Hedgehog on Thursday 2nd December 13:18
So many things to take into account. Refineries use the unwanted or less profitable fractions to power the process. So not very easy to nail down.
JonnyVTEC said:
Drag = 1/2 x density x Velocity squared. In terms of primary resistance to travel at speed.
Just often these calculations ignore the high road speed when trying to compare the work done.
Aero drag formulae are quite often misunderstood, and I’m not sure but I think you may have fallen into the same trap.Just often these calculations ignore the high road speed when trying to compare the work done.
The equation you quote is the one to calculate FORCE.
However, power = force x velocity.
Therefore power is proportional to velocity cubed.
Therefore energy per unit of distance is proportional to velocity squared.
In other words, energy per mile is directly proportional to the force required.
What this means is that if you double the speed you will typically need 4 times as much fuel to overcome drag for a fixed journey length. Whereas the fuel to overcome tyre rolling resistance remains broadly the same regardless of speed.
Drag is the fundamental and immutable reason why reducing speed limits reduces per mile fuel consumption and emissions.
It is essentially the only thing stopping us from travelling faster ‘for free’. Few people seem to understand how important drag is to energy consumption, probably because they can’t really see it.
Anyway,
to answer the question "How much fossil fuel is needed to travel 210 miles in a Tesla Model S" I have done my best to try and work it out.
The answer is 3.24 gallons of petrol.
The reason I picked 210 miles is that is the maximum average I got out of one over 140,000 miles.
Please fell free to criticise. Sources for data below. The data is all over the place.
My logic is as follows.
An 85kWh Tesla Model S charges to 80 kWh, 80kWh of electricity is used up over 210 miles.
16% of the energy in the home charging box is lost between the charger and the car battery. Therefore your 80kWh of electricity was actually 95.23 kWh.
8.2% of your 95.23 kWh was lost between your house and the power station in transmission and distribution. So your 95.23 kWh was actually 103.7 kWh at source.
UK power mix is 42% gas, 9% coal. The other components are clean.
Therefore of 103.7 kWh 43.5 kWh comes from gas.
Therefore 9.3 kWh comes from coal.
43.5 kWh of gas@.13kWh/cubic ft is 334 cu/ft if gas burnt.
9.3 kWh of coal@.88kWh/lb is 11.2 lbs of coal burnt.
146.3 cu/ft of gas is the equivalent energy density as 1 UK gallon of petrol.
334 cu/ft2 of gas @135,000 BTU/UK gallon is the energy equivalent of 2.3 UK gallons
11.2 lbs of coal burnt @123,800 BTU/gallon equivalent is 0.94 UK gallons
Therefore power stations have to burn the equivalent of 3.24 gallons of petrol for the driver to travel 210 miles in a Tesla Model S
Sources
Energy Loss between wall and battery
https://www.greencarcongress.com/2018/09/20180905-...
Converting Energy Density between Fuels
https://en.wikipedia.org/wiki/Gasoline_gallon_equi...
Energy Density of different Fuels
https://www.eia.gov/tools/faqs/faq.php?id=667&...
Grid Transmission Losses
https://www.nationalgrideso.com/document/144711/do...
Energy Density
https://www.generatorjoe.net/html/energy.html
Not to bad I suppose.
to answer the question "How much fossil fuel is needed to travel 210 miles in a Tesla Model S" I have done my best to try and work it out.
The answer is 3.24 gallons of petrol.
The reason I picked 210 miles is that is the maximum average I got out of one over 140,000 miles.
Please fell free to criticise. Sources for data below. The data is all over the place.
My logic is as follows.
An 85kWh Tesla Model S charges to 80 kWh, 80kWh of electricity is used up over 210 miles.
16% of the energy in the home charging box is lost between the charger and the car battery. Therefore your 80kWh of electricity was actually 95.23 kWh.
8.2% of your 95.23 kWh was lost between your house and the power station in transmission and distribution. So your 95.23 kWh was actually 103.7 kWh at source.
UK power mix is 42% gas, 9% coal. The other components are clean.
Therefore of 103.7 kWh 43.5 kWh comes from gas.
Therefore 9.3 kWh comes from coal.
43.5 kWh of gas@.13kWh/cubic ft is 334 cu/ft if gas burnt.
9.3 kWh of coal@.88kWh/lb is 11.2 lbs of coal burnt.
146.3 cu/ft of gas is the equivalent energy density as 1 UK gallon of petrol.
334 cu/ft2 of gas @135,000 BTU/UK gallon is the energy equivalent of 2.3 UK gallons
11.2 lbs of coal burnt @123,800 BTU/gallon equivalent is 0.94 UK gallons
Therefore power stations have to burn the equivalent of 3.24 gallons of petrol for the driver to travel 210 miles in a Tesla Model S
Sources
Energy Loss between wall and battery
https://www.greencarcongress.com/2018/09/20180905-...
Converting Energy Density between Fuels
https://en.wikipedia.org/wiki/Gasoline_gallon_equi...
Energy Density of different Fuels
https://www.eia.gov/tools/faqs/faq.php?id=667&...
Grid Transmission Losses
https://www.nationalgrideso.com/document/144711/do...
Energy Density
https://www.generatorjoe.net/html/energy.html
Not to bad I suppose.
Where has your 9% coal come from? It hasn't been that high for years has it?
ETA: That 9% figure seems to be from 2017. In 2020 our electricity generation was 1.8% coal, 35.7% gas. Plug those numbers into your calculations and it'll come out at about 2 gallons or something (probably slightly over 2)? Which just goes to show how quickly our electricity generation is evolving!
Of course if you charge at night the mix will be even more heavily skewed away from fossil fuels.
ETA: That 9% figure seems to be from 2017. In 2020 our electricity generation was 1.8% coal, 35.7% gas. Plug those numbers into your calculations and it'll come out at about 2 gallons or something (probably slightly over 2)? Which just goes to show how quickly our electricity generation is evolving!
Of course if you charge at night the mix will be even more heavily skewed away from fossil fuels.
Edited by kambites on Thursday 9th December 13:03
politeperson said:
Anyway,
to answer the question "How much fossil fuel is needed to travel 210 miles in a Tesla Model S" I have done my best to try and work it out.
The answer is 3.24 gallons of petrol.
The reason I picked 210 miles is that is the maximum average I got out of one over 140,000 miles.
Please fell free to criticise. Sources for data below. The data is all over the place.
My logic is as follows.
An 85kWh Tesla Model S charges to 80 kWh, 80kWh of electricity is used up over 210 miles.
16% of the energy in the home charging box is lost between the charger and the car battery. Therefore your 80kWh of electricity was actually 95.23 kWh.
8.2% of your 95.23 kWh was lost between your house and the power station in transmission and distribution. So your 95.23 kWh was actually 103.7 kWh at source.
UK power mix is 42% gas, 9% coal. The other components are clean.
Therefore of 103.7 kWh 43.5 kWh comes from gas.
Therefore 9.3 kWh comes from coal.
43.5 kWh of gas@.13kWh/cubic ft is 334 cu/ft if gas burnt.
9.3 kWh of coal@.88kWh/lb is 11.2 lbs of coal burnt.
146.3 cu/ft of gas is the equivalent energy density as 1 UK gallon of petrol.
334 cu/ft2 of gas @135,000 BTU/UK gallon is the energy equivalent of 2.3 UK gallons
11.2 lbs of coal burnt @123,800 BTU/gallon equivalent is 0.94 UK gallons
Therefore power stations have to burn the equivalent of 3.24 gallons of petrol for the driver to travel 210 miles in a Tesla Model S
Sources
Energy Loss between wall and battery
https://www.greencarcongress.com/2018/09/20180905-...
Converting Energy Density between Fuels
https://en.wikipedia.org/wiki/Gasoline_gallon_equi...
Energy Density of different Fuels
https://www.eia.gov/tools/faqs/faq.php?id=667&...
Grid Transmission Losses
https://www.nationalgrideso.com/document/144711/do...
Energy Density
https://www.generatorjoe.net/html/energy.html
Not to bad I suppose.
What's the equivalent calculation for a car giving 35mpg then? It's obviously far more than 6 gallons, because that's only the consumption from pump onward and ignores the energy used to transport and refine oil.to answer the question "How much fossil fuel is needed to travel 210 miles in a Tesla Model S" I have done my best to try and work it out.
The answer is 3.24 gallons of petrol.
The reason I picked 210 miles is that is the maximum average I got out of one over 140,000 miles.
Please fell free to criticise. Sources for data below. The data is all over the place.
My logic is as follows.
An 85kWh Tesla Model S charges to 80 kWh, 80kWh of electricity is used up over 210 miles.
16% of the energy in the home charging box is lost between the charger and the car battery. Therefore your 80kWh of electricity was actually 95.23 kWh.
8.2% of your 95.23 kWh was lost between your house and the power station in transmission and distribution. So your 95.23 kWh was actually 103.7 kWh at source.
UK power mix is 42% gas, 9% coal. The other components are clean.
Therefore of 103.7 kWh 43.5 kWh comes from gas.
Therefore 9.3 kWh comes from coal.
43.5 kWh of gas@.13kWh/cubic ft is 334 cu/ft if gas burnt.
9.3 kWh of coal@.88kWh/lb is 11.2 lbs of coal burnt.
146.3 cu/ft of gas is the equivalent energy density as 1 UK gallon of petrol.
334 cu/ft2 of gas @135,000 BTU/UK gallon is the energy equivalent of 2.3 UK gallons
11.2 lbs of coal burnt @123,800 BTU/gallon equivalent is 0.94 UK gallons
Therefore power stations have to burn the equivalent of 3.24 gallons of petrol for the driver to travel 210 miles in a Tesla Model S
Sources
Energy Loss between wall and battery
https://www.greencarcongress.com/2018/09/20180905-...
Converting Energy Density between Fuels
https://en.wikipedia.org/wiki/Gasoline_gallon_equi...
Energy Density of different Fuels
https://www.eia.gov/tools/faqs/faq.php?id=667&...
Grid Transmission Losses
https://www.nationalgrideso.com/document/144711/do...
Energy Density
https://www.generatorjoe.net/html/energy.html
Not to bad I suppose.
rscott said:
What's the equivalent calculation for a car giving 35mpg then? It's obviously far more than 6 gallons, because that's only the consumption from pump onward and ignores the energy used to transport and refine oil.
I suspect it works out somewhere around the 8 gallon mark if you have a best stab at making the calculation "equivalent". The average uk grid carbon intensity is a measure for "delivered energy" ie energy consumed at the point of use. (averaged over the network)
See:
https://carbonintensity.org.uk/
"The Carbon Intensity forecast includes CO2 emissions related to electricity generation only. This includes emissions from all large metered power stations, interconnector imports, transmission and distribution losses, and accounts for national electricity demand, embedded wind and solar generation."
Today it sits at around 180g/kWh as a daily average;
A model S uses typically around 21 kWh per 100 km driven (3 ml/kWh)
So, 210 miles is 210 / 3.2 = 71 kWh.
Add on 10% charging loses (dc fast charging is more efficient than AC slow charging, and most Teslas driven long distances use the supercharging network), for a total energy consumption at point of load of 78 kWh, which at todays average cabon intensity means pretty much 14kg of CO2 emitted by the National grid
That is the same carbon dioxide emitted as burning 1.3 gallons of petrol, for an eMPG equivalent of 162 ml/gallon
A comparible sized ICE vehicle, manages around 45 mpg at best over the same journey (assuming light traffic and it's being driven pretty carefully), which is 4.7 gallons of fuel at the vehicle tank consumption level. So before we have even considered that the fuel must get delivered to the fuel station, and ignoring any refinery penalties, that's an additional 3.4 gallons of fuel and 37 kg of CO2 emitted to drive exactly the same journey
See:
https://carbonintensity.org.uk/
"The Carbon Intensity forecast includes CO2 emissions related to electricity generation only. This includes emissions from all large metered power stations, interconnector imports, transmission and distribution losses, and accounts for national electricity demand, embedded wind and solar generation."
Today it sits at around 180g/kWh as a daily average;
A model S uses typically around 21 kWh per 100 km driven (3 ml/kWh)
So, 210 miles is 210 / 3.2 = 71 kWh.
Add on 10% charging loses (dc fast charging is more efficient than AC slow charging, and most Teslas driven long distances use the supercharging network), for a total energy consumption at point of load of 78 kWh, which at todays average cabon intensity means pretty much 14kg of CO2 emitted by the National grid
That is the same carbon dioxide emitted as burning 1.3 gallons of petrol, for an eMPG equivalent of 162 ml/gallon
A comparible sized ICE vehicle, manages around 45 mpg at best over the same journey (assuming light traffic and it's being driven pretty carefully), which is 4.7 gallons of fuel at the vehicle tank consumption level. So before we have even considered that the fuel must get delivered to the fuel station, and ignoring any refinery penalties, that's an additional 3.4 gallons of fuel and 37 kg of CO2 emitted to drive exactly the same journey
Gassing Station | EV and Alternative Fuels | Top of Page | What's New | My Stuff