Energy requirements of FF versus EVs

Our transport is heavily oil-based. What are the alternatives?

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Little John
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Energy requirements of FF versus EVs

Post by Little John »

So, once this fleet of millions of EVs is rolled out, where is the extra energy coming from to supply the power stations to provide the electricity to charge them all?




This post and those following have been split from the thread about urban myths.
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clv101
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Post by clv101 »

Little John wrote:So, once this fleet of millions of EVs is rolled out, where is the extra energy coming from to supply the power stations to provide the electricity to charge them all?
It doesn't actually take that much. In the UK, a large chunk of the car fleet could switch to EV without any more generating capacity needed to be added, and the extra energy needed is pretty modest.

In 2018 we drove 255 billion miles (cars and taxis), at 250 Wh per mile that's 63 TWh. At say 50% penetration it's more like 30 TWh, compared with our current power use of around 320 TWh - so just a 10% increase needed, or +20% to do the lot.

Also remember, that back ~2005 we generated around 400 TWh, enough above today's generation to power all the electric cars.
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Post by adam2 »

clv101 wrote:
Little John wrote:So, once this fleet of millions of EVs is rolled out, where is the extra energy coming from to supply the power stations to provide the electricity to charge them all?
It doesn't actually take that much. In the UK, a large chunk of the car fleet could switch to EV without any more generating capacity needed to be added, and the extra energy needed is pretty modest.

In 2018 we drove 255 billion miles (cars and taxis), at 250 Wh per mile that's 63 TWh. At say 50% penetration it's more like 30 TWh, compared with our current power use of around 320 TWh - so just a 10% increase needed, or +20% to do the lot.

Also remember, that back ~2005 we generated around 400 TWh, enough above today's generation to power all the electric cars.
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Little John
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Post by Little John »

clv101 wrote:
Little John wrote:So, once this fleet of millions of EVs is rolled out, where is the extra energy coming from to supply the power stations to provide the electricity to charge them all?
It doesn't actually take that much. In the UK, a large chunk of the car fleet could switch to EV without any more generating capacity needed to be added, and the extra energy needed is pretty modest.

In 2018 we drove 255 billion miles (cars and taxis), at 250 Wh per mile that's 63 TWh. At say 50% penetration it's more like 30 TWh, compared with our current power use of around 320 TWh - so just a 10% increase needed, or +20% to do the lot.

Also remember, that back ~2005 we generated around 400 TWh, enough above today's generation to power all the electric cars.
Hang on a minute. If the extra electrical energy required to power the national fleet of cars is inconsequential, then that must mean that the proportion of total annual hydrocarbon consumption of that fleet as it currently stands is also inconsequential. In which case, what is the big deal about turning them all over to electric? You don't get it both ways. Energy is energy.
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Post by PS_RalphW »

The problem with ice cars is their inefficiency. They use 4 times more energy to go the same distance.
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Post by Little John »

PS_RalphW wrote:The problem with ice cars is their inefficiency. They use 4 times more energy to go the same distance.
4 times more energy efficient than what? Their EV equivalent? Are you merely comparing energy use at the point of locomotion? Or, are you including in that comparison all of the energy required to get the respective vehicles to the point of locomotion? I ask this question because the energy loss in terms of conversion from the feed stock energy entering the power station and then being turned into electricity plus all of the losses incurred in distribution of that electricity to your home before it is then transferred into an EV is about 65-70%.
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Post by fuzzy »

Plus the 70% waste heat being used to demist and dry your car and warm the passenger for 1/2 the UK year. An example of academics and reporters not having to drive to work for a living.
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Post by vtsnowedin »

There are too many variables to draw a single rule. A grid charged EV using coal fired electricity with a long old and inefficient grid will have a much different bottom line EROEI wise then one charged by hydro or wind power generated on site or nearby. One thing is certain and that is you can't fill your ICE vehicle with solar PE or hydro power without massive conversion losses.
My own situation is a bit interesting. Much of the states (and my utility's) power comes from Hydro-Quebec over high capacity DC and AC lines that have a line loss of about seven percent. But I only pay for what actually gets delivered so seven percent more water going through the turbines up in Labrador at Churchill falls is nothing to me. Now when I receive my Cyber truck I might drive it thirty miles a day on average but one hundred fifty on summer work days. 150 miles takes 45 KWHs to recharge and can't be done overnight without three phase power hookups. The nearest three phase power to me is five miles away.
I don't know if Tesla power walls can be used to to fast charge overnight if they don't have three phase backup. I'm thinking two 15KWH Tesla powerwalls hooked to 5KW of solar panels might provide all the energy to run the cyber truck but that is a considerable money investment just to never have to buy gas again. At the current local $2.70 for gas and .26/KWH it is not practical to generate and store your own but let gas rise to $6 to $10 and reconsideration will be needed.
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Post by Little John »

vtsnowedin wrote:There are too many variables to draw a single rule. A grid charged EV using coal fired electricity with a long old and inefficient grid will have a much different bottom line EROEI wise then one charged by hydro or wind power generated on site or nearby. One thing is certain and that is you can't fill your ICE vehicle with solar PE or hydro power without massive conversion losses.
My own situation is a bit interesting. Much of the states (and my utility's) power comes from Hydro-Quebec over high capacity DC and AC lines that have a line loss of about seven percent. But I only pay for what actually gets delivered so seven percent more water going through the turbines up in Labrador at Churchill falls is nothing to me. Now when I receive my Cyber truck I might drive it thirty miles a day on average but one hundred fifty on summer work days. 150 miles takes 45 KWHs to recharge and can't be done overnight without three phase power hookups. The nearest three phase power to me is five miles away.
I don't know if Tesla power walls can be used to to fast charge overnight if they don't have three phase backup. I'm thinking two 15KWH Tesla powerwalls hooked to 5KW of solar panels might provide all the energy to run the cyber truck but that is a considerable money investment just to never have to buy gas again. At the current local $2.70 for gas and .26/KWH it is not practical to generate and store your own but let gas rise to $6 to $10 and reconsideration will be needed.
If there are too many variables to draw a single rule, people should be way more reticent about making singular claims about EV vehicles using less carbon overall. Furthermore, if the only way that EVs can be shown to be more carbon friendly than ICE vehicles is via the use of renewables as the feed-stock energy source, then it needs to also explained how renewables are going to feed an entirely replaced vehicle fleet at the same time as replace the more general energy feed-stock of the grid electricity supply.

There is a lot of vague, "green" bullshit floating around and that's for sure.
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Post by clv101 »

Little John wrote:There is a lot of vague, "green" bullshit floating around and that's for sure.
Indeed - the key point to remember though is that EV don't actually use much electricity. Running half the cars in the UK would require approximately 10% more electricity than we currently generate, not as much extra as we were generating a decade ago.

First step to sensible analysis needs to be ball park understand of the magnitudes involve. Most people have a poor understanding of ball park magnitudes, not just regarding EVs and the energy system, but in many walks of life. Rosling's Factfullness being an recent example of this.
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Post by vtsnowedin »

It is pretty clear that we can build new renewable power sources faster then we can build new EVs to use the power. If you consider that sales will go first to those with short regular commutes up through average drivers and only need to serve those that drive well over average miles per day after that two thirds of the auto market (USA currently 100 million vehicles) there is no reason to doubt our ability to charge the cars from renewables in total volume if not each specific car.
At $2.70 a gallon a ICE car that gets 30 MPG cost 9 cents per mile for fuel. A Tesla getting 3.3 miles per KWH at $0.26/ KWH also cost 9 cents a mile after you compute battery efficiency stated at 85%. Those are both my local prices today and when you consider that my present pickup only gets 17MPG electric is already in the lead. Drivers out west using Hydro power at $0.10/KWH are already looking at cost savings by switching to electric.
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Post by clv101 »

In the UK, petrol is £4.70 per US gallon and electricity £0.15 per kWh.

US ratio, 2.7/0.26 = 10.4
UK ratio, 4.7/0.15 = 31.3

If EVs are looking financially viable in the US, the numbers are three times better over here!
Last edited by clv101 on Sun Jan 12, 2020 11:08 am, edited 1 time in total.
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Post by vtsnowedin »

clv101 wrote:In the UK, petrol is £4.70 per US gallon and electricity £0.15 per kWh.

UK ratio, 2.7/0.26 = 10.4
US ratio, 4.7/0.15 = 31.3

If EVs are looking financially viable in the US, the numbers are three times better over here!
I think you swapped the labels there but I take your point. Of course your high fuel price are from high taxes to suppress demand and reduce your dependence on imported oil.
What do they do with the tax money?
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Post by PS_RalphW »

It goes to the central goverent to use as they please. Very few UK taxes are allocated to particular budgets.
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Post by Little John »

clv101 wrote:
Little John wrote:There is a lot of vague, "green" bullshit floating around and that's for sure.
Indeed - the key point to remember though is that EV don't actually use much electricity. Running half the cars in the UK would require approximately 10% more electricity than we currently generate, not as much extra as we were generating a decade ago.

First step to sensible analysis needs to be ball park understand of the magnitudes involve. Most people have a poor understanding of ball park magnitudes, not just regarding EVs and the energy system, but in many walks of life. Rosling's Factfullness being an recent example of this.
So, if a completely replaced ICE fleet of EVs is only going to raise electricity consumption levels by 10%, then this must mean that the existing ICE fleet is only using a similarly very small fraction of hydrocarbon fuel...right? In which case, why go to all of the infrastructural upheaval of changing the fleet when there are obviously many more more larger, low hanging fruit in the economy to grab hold of?
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