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Per capita per year, the US consumes 13.0 MWh of electricity and 436.6 gallons of gasoline. With ~132k BTU of energy per gallon, that's 16.9 MWh. Let's say ele

Per capita per year, the US consumes 13.0 MWh of electricity and 436.6 gallons of gasoline. With ~132k BTU of energy per gallon, that's 16.9 MWh. Let's say electric cars are 50% more efficient in terms of energy consumption; that's still a 65% increase in the amount of electricity production required. As we move to EVs and renewables, this extra energy is going to come from keeping fossil fuel plants online that would have otherwise been shut down. Counting the energy use of EVs as potentially from renewable sources is just feel good and ignores reality. The marginal electrical consumption caused by Teslas coming off the line today will not come from renewable sources over the lifetime of the vehicle, even if you assume a very healthy exponential ramp from today. You're refuting one bad argument with another, which unfortunately is pretty much par for the course for discussions on energy policy. Even with this, the shift is still well worth doing, not least of which because the distributed storage it offers is likely the only way we'll be able to hit 100% renewables down the track.

_ph_ 8y ago
I cannot comment on the US numbers, but the German numbers are as following: - total electricity production is around 600 TWh/year - switching all cars to electricity would require about 120 TWh/year (44M cars x 14000km/year * 20kWh/100km) That would be a 20% increase in electricity production required, but from that one can deduct quite a bit for fuel refining and distribution, better buffering of peak electricity production etc. If you take the energy content of fuel, an electric car is roughly 4x as efficient as a combustion engine. While combustion engines may reach peak efficiencies of 40%, the average over the whole driving cycle is less than 20%, as the peak efficiency is only reached in a narrow band of power productions - usually at highway speeds. That is the reason hybrid cars save fuel, the electric component reduces the inefficiencies of certain parts of the driving cycle.
- reitzensteinm 8y ago
  I'm not surprised the German numbers are better. But even there, with Germany's remarkable progress, a Tesla bought today will be scrapped before Germany reaches 120% of today's electrical production in renewables. Fair enough; I should have used 25% instead of 50%. In my head I was multiplying by the energy efficiency of electrical production but that of course is not relevant to this calculation. The irony of correcting a bad argument with a bad argument while complaining about the same is not lost on me. I believe my point stands.
  - _ph_ 8y ago
    In Germany, far more reneweable power is added to the grid as the consumption could increase. With about 44 million cars on the road, every year 3 million new cars are sold, so it would take 15 years to add that extra 10-15% of electricity consumption to the grid. Whether the grid reaches 100% reneweable during the lifetime of an electric car bought today or not might not be clear, but the point being was, it is guaranteed to contain way more reneweables as of today and with that the base of the calculations was wrong.
    - reitzensteinm 8y ago
      If you're adding marginal consumption to the grid that does not exist today, you can't account for it as being in part powered by renewables. You are producing no more renewable energy than previously, and fossil fuel consumption will increase by exactly the amount you're adding to the grid. I'm not arguing that EVs aren't a good idea. I'm just in favor of being clear about the choice that's being made; a switch to 100% EVs would result in significantly increased electricity consumption powered by fossil fuels until renewables catch up, but lower overall carbon emissions since you're burning the fossil fuels more efficiently.
      - _ph_ 8y ago
        No. At best we could add 6% more electric cars per year - if only electric cars would be sold. That is the renewal rate for cars in Germany. This means, the energy consumption would increase by 1.5% per year. The addition of reneweable energy to the grid per year far exceeds the amount of energy that could be used by electric cars even at 100% market share. Which they are unfortunately far from. So the mix gets cleaner even after accounting all new reneweable energy for the electricity demands of electric cars.
        reitzensteinm 8y ago
        It is simply not relevant that renewable energy is being added to the grid faster than EVs are increasing energy consumption. If you add energy consumption to the grid, you are powering it with your dirtiest power, which you'd otherwise be shutting off. EVs are still superior when powering them entirely with fossil fuels. I'm not trying to argue against them. But it's important to be truthful about where the energy is coming from.
- sliken 8y ago
  Keep in mind that 600TWh/year is likely a capacity of at least double that. But the peak rate is only under worst case scenarios like a sustained heat waves. Unfortunately that high peak capacity is very expensive and goes unused for the majority of the year. Electric cars consume quite a bit of power, but the longer range cars like the Audi, Jaguar, Tesla, top of the line leaf, and bolt all have a 200 mile or so range. So under normal use (somewhere around 12,000 miles a year) they don't need charged every day. So generally cars can charge off peak, but in times of dire need I can see only allowing cars to charge when there's a surplus of power... strangely enough these surpluses are becoming common because of solar. Sometimes utilities even have to pay to get rid of the power.
D_Alex 8y ago
>Per capita per year, the US consumes 13.0 MWh of electricity and 436.6 gallons of gasoline. With ~132k BTU of energy per gallon, that's 16.9 MWh. >Let's say electric cars are 50% more efficient in terms of energy consumption Let's look up the numbers, instead of guessing. The average fuel economy of an american car is apparently 24.7 mpg, whereas a Tesla Model S gets 3.0 miles per kWhr. So if you replace one with the other, you will need about 3.5 MWhr of extra electricity. 27% extra. The good thing is that we should be able to charge the EVs at the time of our choosing, and maybe even discharge them into the grid when the power demand outweighs the generation. The utilisation of wind, solar and off-peak baseload power should increase.
- benj111 8y ago
  Your last paragraph is key. Even if EVs do double electricity demand, its mainly going to be off peak, and you've got 8+ hours you can spread the charging over. Maybe not a great match to solar, but a good match for wind.
- reitzensteinm 8y ago
  Yes, I completely fucked up the math. Muphry's Law. But my point still stands; you aren't powering that EV with renewables until the grid goes over 100% of today's production. The fact that you "can" doesn't mean you are.
  - SECProto 8y ago
    No, you're powering it with whatever the grid is using. Which is what invalidates your point. Even coal is cleaner [1] than gas. The grid is continuously getting cleaner, and your diesel only gets dirtier as it gets older. [1] https://www.bloomberg.com/news/articles/2019-01-15/electric-cars-seen-getting-cleaner-even-where-grids-rely-on-coal https://www.bloomberg.com/news/articles/2019-01-15/electric-...
    - reitzensteinm 8y ago
      Wowee, it's not "my" diesel. I am in fact an EV advocate, and they're worth transitioning to even if you're powering them with coal. This is a fact that we agree on. My point is that the grid is not getting continuously cleaner if you're dumping a bunch more load on it. The marginal increase in load will be powered by fossil fuels for a significant amount of time, which is longer than the lifetime of a Tesla built today. You take your dirtiest power offline first (with a sane energy policy). Any extra load you add is by definition delaying that event. EVs are an important next step, and an absolute necessity for stabilizing the grid when transitioning to intermittent renewables. I was replying to a very specific claim made by the parent comment.
kowdermeister 8y ago
You are missing the point. This is a long run game, since we can easily transition from fossil fuels to alternate energy source without having to replace fundamentally how EV engines work. All they need is electrons, not exploding fossil fuel. These electrons can come from any source. If it's fossil today it doesn't matter. 20, 50. 100 years from now the source of energy can shift significantly while the transportation industry just wouldn't care anymore.
sliken 8y ago
ICE cars are around 15% efficient. Electric cars are generally 85% to 90% efficient. "50% more" is a pretty big understatement. 1.5x * 15 is only 22.5% efficient still around 1/4th as efficient as an electric car. Also given solar's growth and the time it will take for most cars to be electric there's plenty of room for more solar production. California now requires solar on all new homes, and it's getting ever more price effective to use renewables. Seems like I see a few stories a week about a coal, NG, or similar peaker plant being cancelled, or decomissioned in favor of battery storage, solar, or both... for purely economic reasons. A 75kw battery in a tesla gives you a range of 310 miles or so. So that's 4 miles or so per kw. So if I install the smallest Tesla solar system (4kw for $8,000) and being in central California I get a fair bit of sun. Should easily make 15-20kwh in the winter, and a fair bit more in the summer. That's 80 ish miles a day in the winter, and more in the summer. I drive about 30 miles a day on average. So with a 8kw solar system I'd likely handle my driving needs and put a big dent in my other power needs. Tesla's new solar pricing puts it around $2.00 a watt installed. $16,000 isn't cheap, but our power bill isn't cheap either, especially in the summer. As a nice bonus solar panels noticeably decrease the heat load in the attic, saving airconditioning costs. Amusingly solar panels over parking lots (so they provide shade) actually save a fair amount of gas. The huge win is when everyone runs their AC flat out for 15 minutes when they get into their 130F cars, if their car is closer to ambient they spend much less gas on the AC. While solar does contribute to the "duck" shaped power production curve, cars typically spend the vast majority of their time parked, and can be programmed to use power whenever there is a surplus/whenever the price is lowest. So while electric cars can consume large amounts of power, they generally aren't picky on when they get it. At least for home users they typically schedule charging for whatever time the cheapest rates start.

_ph_ 8y ago

I cannot comment on the US numbers, but the German numbers are as following: - total electricity production is around 600 TWh/year - switching all cars to electricity would require about 120 TWh/year (44M cars x 14000km/year * 20kWh/100km) That would be a 20% increase in electricity production required, but from that one can deduct quite a bit for fuel refining and distribution, better buffering of peak electricity production etc. If you take the energy content of fuel, an electric car is roughly 4x as efficient as a combustion engine. While combustion engines may reach peak efficiencies of 40%, the average over the whole driving cycle is less than 20%, as the peak efficiency is only reached in a narrow band of power productions - usually at highway speeds. That is the reason hybrid cars save fuel, the electric component reduces the inefficiencies of certain parts of the driving cycle.

reitzensteinm 8y ago
I'm not surprised the German numbers are better. But even there, with Germany's remarkable progress, a Tesla bought today will be scrapped before Germany reaches 120% of today's electrical production in renewables. Fair enough; I should have used 25% instead of 50%. In my head I was multiplying by the energy efficiency of electrical production but that of course is not relevant to this calculation. The irony of correcting a bad argument with a bad argument while complaining about the same is not lost on me. I believe my point stands.
- _ph_ 8y ago
  In Germany, far more reneweable power is added to the grid as the consumption could increase. With about 44 million cars on the road, every year 3 million new cars are sold, so it would take 15 years to add that extra 10-15% of electricity consumption to the grid. Whether the grid reaches 100% reneweable during the lifetime of an electric car bought today or not might not be clear, but the point being was, it is guaranteed to contain way more reneweables as of today and with that the base of the calculations was wrong.
  - reitzensteinm 8y ago
    If you're adding marginal consumption to the grid that does not exist today, you can't account for it as being in part powered by renewables. You are producing no more renewable energy than previously, and fossil fuel consumption will increase by exactly the amount you're adding to the grid. I'm not arguing that EVs aren't a good idea. I'm just in favor of being clear about the choice that's being made; a switch to 100% EVs would result in significantly increased electricity consumption powered by fossil fuels until renewables catch up, but lower overall carbon emissions since you're burning the fossil fuels more efficiently.
    - _ph_ 8y ago
      No. At best we could add 6% more electric cars per year - if only electric cars would be sold. That is the renewal rate for cars in Germany. This means, the energy consumption would increase by 1.5% per year. The addition of reneweable energy to the grid per year far exceeds the amount of energy that could be used by electric cars even at 100% market share. Which they are unfortunately far from. So the mix gets cleaner even after accounting all new reneweable energy for the electricity demands of electric cars.
      - reitzensteinm 8y ago
        It is simply not relevant that renewable energy is being added to the grid faster than EVs are increasing energy consumption. If you add energy consumption to the grid, you are powering it with your dirtiest power, which you'd otherwise be shutting off. EVs are still superior when powering them entirely with fossil fuels. I'm not trying to argue against them. But it's important to be truthful about where the energy is coming from.
sliken 8y ago
Keep in mind that 600TWh/year is likely a capacity of at least double that. But the peak rate is only under worst case scenarios like a sustained heat waves. Unfortunately that high peak capacity is very expensive and goes unused for the majority of the year. Electric cars consume quite a bit of power, but the longer range cars like the Audi, Jaguar, Tesla, top of the line leaf, and bolt all have a 200 mile or so range. So under normal use (somewhere around 12,000 miles a year) they don't need charged every day. So generally cars can charge off peak, but in times of dire need I can see only allowing cars to charge when there's a surplus of power... strangely enough these surpluses are becoming common because of solar. Sometimes utilities even have to pay to get rid of the power.

D_Alex 8y ago

>Per capita per year, the US consumes 13.0 MWh of electricity and 436.6 gallons of gasoline. With ~132k BTU of energy per gallon, that's 16.9 MWh. >Let's say electric cars are 50% more efficient in terms of energy consumption Let's look up the numbers, instead of guessing. The average fuel economy of an american car is apparently 24.7 mpg, whereas a Tesla Model S gets 3.0 miles per kWhr. So if you replace one with the other, you will need about 3.5 MWhr of extra electricity. 27% extra. The good thing is that we should be able to charge the EVs at the time of our choosing, and maybe even discharge them into the grid when the power demand outweighs the generation. The utilisation of wind, solar and off-peak baseload power should increase.

benj111 8y ago
Your last paragraph is key. Even if EVs do double electricity demand, its mainly going to be off peak, and you've got 8+ hours you can spread the charging over. Maybe not a great match to solar, but a good match for wind.
reitzensteinm 8y ago
Yes, I completely fucked up the math. Muphry's Law. But my point still stands; you aren't powering that EV with renewables until the grid goes over 100% of today's production. The fact that you "can" doesn't mean you are.
- SECProto 8y ago
  No, you're powering it with whatever the grid is using. Which is what invalidates your point. Even coal is cleaner [1] than gas. The grid is continuously getting cleaner, and your diesel only gets dirtier as it gets older. [1] https://www.bloomberg.com/news/articles/2019-01-15/electric-cars-seen-getting-cleaner-even-where-grids-rely-on-coal https://www.bloomberg.com/news/articles/2019-01-15/electric-...
  - reitzensteinm 8y ago
    Wowee, it's not "my" diesel. I am in fact an EV advocate, and they're worth transitioning to even if you're powering them with coal. This is a fact that we agree on. My point is that the grid is not getting continuously cleaner if you're dumping a bunch more load on it. The marginal increase in load will be powered by fossil fuels for a significant amount of time, which is longer than the lifetime of a Tesla built today. You take your dirtiest power offline first (with a sane energy policy). Any extra load you add is by definition delaying that event. EVs are an important next step, and an absolute necessity for stabilizing the grid when transitioning to intermittent renewables. I was replying to a very specific claim made by the parent comment.

kowdermeister 8y ago

You are missing the point. This is a long run game, since we can easily transition from fossil fuels to alternate energy source without having to replace fundamentally how EV engines work. All they need is electrons, not exploding fossil fuel. These electrons can come from any source. If it's fossil today it doesn't matter. 20, 50. 100 years from now the source of energy can shift significantly while the transportation industry just wouldn't care anymore.

sliken 8y ago

ICE cars are around 15% efficient. Electric cars are generally 85% to 90% efficient. "50% more" is a pretty big understatement. 1.5x * 15 is only 22.5% efficient still around 1/4th as efficient as an electric car. Also given solar's growth and the time it will take for most cars to be electric there's plenty of room for more solar production. California now requires solar on all new homes, and it's getting ever more price effective to use renewables. Seems like I see a few stories a week about a coal, NG, or similar peaker plant being cancelled, or decomissioned in favor of battery storage, solar, or both... for purely economic reasons. A 75kw battery in a tesla gives you a range of 310 miles or so. So that's 4 miles or so per kw. So if I install the smallest Tesla solar system (4kw for $8,000) and being in central California I get a fair bit of sun. Should easily make 15-20kwh in the winter, and a fair bit more in the summer. That's 80 ish miles a day in the winter, and more in the summer. I drive about 30 miles a day on average. So with a 8kw solar system I'd likely handle my driving needs and put a big dent in my other power needs. Tesla's new solar pricing puts it around $2.00 a watt installed. $16,000 isn't cheap, but our power bill isn't cheap either, especially in the summer. As a nice bonus solar panels noticeably decrease the heat load in the attic, saving airconditioning costs. Amusingly solar panels over parking lots (so they provide shade) actually save a fair amount of gas. The huge win is when everyone runs their AC flat out for 15 minutes when they get into their 130F cars, if their car is closer to ambient they spend much less gas on the AC. While solar does contribute to the "duck" shaped power production curve, cars typically spend the vast majority of their time parked, and can be programmed to use power whenever there is a surplus/whenever the price is lowest. So while electric cars can consume large amounts of power, they generally aren't picky on when they get it. At least for home users they typically schedule charging for whatever time the cheapest rates start.