Electric cars, does everyone really think they are amazing.
Discussion
98elise said:
What are you on about!
In the UK about 35m vehicles on the road, and each BEV will need an average of 7-8kWh of energy per day (based on the average mileage of 8k). Assuming all vehicles are BEV (which won't happen) thats about 30GWh total. Looking at a few scenarios for delivering 30GWh a day
> Spread evenly across the day would be 1.25GW.
> Confined to 12 hours per day it would be 2.5GW.
> Confined to just 6 hours overnight, then its 5GW.
We have about 10GW spare overnight so even if we were limited to just those hours we would have enough capacity. There are points in the day (especially winter) when changing might need to be throttled, but i suspect that will be managed by unit cost (ie making it cheaper at night).
That's assuming all cars are BEV only, which is I highly doubt will happen.
It helps if we start with good data. Good maths is a bit pointless without decent inputs. In the UK about 35m vehicles on the road, and each BEV will need an average of 7-8kWh of energy per day (based on the average mileage of 8k). Assuming all vehicles are BEV (which won't happen) thats about 30GWh total. Looking at a few scenarios for delivering 30GWh a day
> Spread evenly across the day would be 1.25GW.
> Confined to 12 hours per day it would be 2.5GW.
> Confined to just 6 hours overnight, then its 5GW.
We have about 10GW spare overnight so even if we were limited to just those hours we would have enough capacity. There are points in the day (especially winter) when changing might need to be throttled, but i suspect that will be managed by unit cost (ie making it cheaper at night).
That's assuming all cars are BEV only, which is I highly doubt will happen.
Cars account for 244 billion vehicle miles a year. UK government source here:
https://www.gov.uk/government/uploads/system/uploa...
It seems that big electric cars like Teslas seem to chew through 0.3 kW per mile, 0.4 if you are pressing on. Lets call it 0.3.
So we need to find 0.3 x 244,000,000,000 kW/h a year to run the UK passenger vehicle fleet on electricity.
Assuming the load is spread evenly throughout the year, that's 197 GW/day. Again, assuming that the load is spread evenly throughout the day (it isn't, it will be concentrated overnight), that's 8.2 GW we need to find. Restricting charging to 12 hours over night, we need to find 16.4GW.
Remember that is 16.4 GW of capacity spread over 12 hours. We have that capacity in the middle of the night, so about 7 of those hours are probably OK. We don't have 16.4 GW free in the evenings in the winter, without building about 10 GW of new capacity - that's 3 Sizewells. We don't have capacity to deal with surges in demand - e.g. Christmas holidays, as every man + dog gets in the car. If you think that the 244 billion miles is distributed in a manner that means some days are 30% more busy than others, then we're looking at 5 Sizewells.
None of this is impossible, but we have to remember we're a country that's taken 10 years to not build a nuclear power station.
SimonYorkshire said:
Seems you cannot even agree among yourselves how many new power stations will be needed,
Some of us included current free capacity or projected renewable capacity or, in my case, what the required supply would be in terms of Hinckley Cs. Oddly all of our estimates fall within one magnitude, yours is one or two magnitudes higher than anyone else's.I am pro-EV, kind of, I want all of the low mileage diesel buyers to swap to them. I also think there is the potential for there to be one that I might want to own one day.
rxe said:
98elise said:
What are you on about!
In the UK about 35m vehicles on the road, and each BEV will need an average of 7-8kWh of energy per day (based on the average mileage of 8k). Assuming all vehicles are BEV (which won't happen) thats about 30GWh total. Looking at a few scenarios for delivering 30GWh a day
> Spread evenly across the day would be 1.25GW.
> Confined to 12 hours per day it would be 2.5GW.
> Confined to just 6 hours overnight, then its 5GW.
We have about 10GW spare overnight so even if we were limited to just those hours we would have enough capacity. There are points in the day (especially winter) when changing might need to be throttled, but i suspect that will be managed by unit cost (ie making it cheaper at night).
That's assuming all cars are BEV only, which is I highly doubt will happen.
It helps if we start with good data. Good maths is a bit pointless without decent inputs. In the UK about 35m vehicles on the road, and each BEV will need an average of 7-8kWh of energy per day (based on the average mileage of 8k). Assuming all vehicles are BEV (which won't happen) thats about 30GWh total. Looking at a few scenarios for delivering 30GWh a day
> Spread evenly across the day would be 1.25GW.
> Confined to 12 hours per day it would be 2.5GW.
> Confined to just 6 hours overnight, then its 5GW.
We have about 10GW spare overnight so even if we were limited to just those hours we would have enough capacity. There are points in the day (especially winter) when changing might need to be throttled, but i suspect that will be managed by unit cost (ie making it cheaper at night).
That's assuming all cars are BEV only, which is I highly doubt will happen.
Cars account for 244 billion vehicle miles a year. UK government source here:
https://www.gov.uk/government/uploads/system/uploa...
It seems that big electric cars like Teslas seem to chew through 0.3 kW per mile, 0.4 if you are pressing on. Lets call it 0.3.
So we need to find 0.3 x 244,000,000,000 kW/h a year to run the UK passenger vehicle fleet on electricity.
Assuming the load is spread evenly throughout the year, that's 197 GW/day. Again, assuming that the load is spread evenly throughout the day (it isn't, it will be concentrated overnight), that's 8.2 GW we need to find. Restricting charging to 12 hours over night, we need to find 16.4GW.
Remember that is 16.4 GW of capacity spread over 12 hours. We have that capacity in the middle of the night, so about 7 of those hours are probably OK. We don't have 16.4 GW free in the evenings in the winter, without building about 10 GW of new capacity - that's 3 Sizewells. We don't have capacity to deal with surges in demand - e.g. Christmas holidays, as every man + dog gets in the car. If you think that the 244 billion miles is distributed in a manner that means some days are 30% more busy than others, then we're looking at 5 Sizewells.
None of this is impossible, but we have to remember we're a country that's taken 10 years to not build a nuclear power station.
Now try and recalculate for those that would suit the use of an EV. Not everyone will. No one is saying an EV will suit everyone.
How much of that 244 billion is done by cars that will not suit the use of an EV?
AND you're assumption is that everyone will need to charge on the same night, every night. If charging is spread over 7 nights (generally I charge my car only two nights/week, some only charge once/week...some charge every night but only top up a couple of kw) the requirement is spread out further.
Edited by ikarl on Wednesday 20th September 17:25
ikarl said:
Your first sentence is good. Well done for that.
Now try and recalculate for those that would suit the use of an EV. Not everyone will. No one is saying an EV will suit everyone.
How much of that 244 billion is done by cars that will not suit the use of an EV?
AND you're assumption is that everyone will need to charge on the same night, every night. If charging is spread over 7 nights (generally I charge my car only two nights/week, some only charge once/week...some charge every night but only top up a couple of kw) the requirement is spread out further.
I'm deliberately not making the assumption that everyone will charge on the same night. The simple fact would be that we need to power 244 billion vehicle miles per annum in an EV world. I've assumed that the mileage will be evenly distributed on 365 days a year, if you assume that it will be distributed differently, the calculations are far worse. Approaching it this way means that all discussions about granny only doing 2 miles are nugatory - I'm looking at the total mileage and the average power draw. Now try and recalculate for those that would suit the use of an EV. Not everyone will. No one is saying an EV will suit everyone.
How much of that 244 billion is done by cars that will not suit the use of an EV?
AND you're assumption is that everyone will need to charge on the same night, every night. If charging is spread over 7 nights (generally I charge my car only two nights/week, some only charge once/week...some charge every night but only top up a couple of kw) the requirement is spread out further.
Edited by ikarl on Wednesday 20th September 17:25
Yes, these figures are for 100% EV penetration, but only in domestic vehicles. Nothing to do with goods transport (which is probably the same again). If we get 50% penetration, then we only have to build 2 Sizewells, not 3. I am assuming you can't build half a Sizewell. As I said, its not impossible, but we have to get our arses in gear.
rxe said:
ikarl said:
Your first sentence is good. Well done for that.
Now try and recalculate for those that would suit the use of an EV. Not everyone will. No one is saying an EV will suit everyone.
How much of that 244 billion is done by cars that will not suit the use of an EV?
AND you're assumption is that everyone will need to charge on the same night, every night. If charging is spread over 7 nights (generally I charge my car only two nights/week, some only charge once/week...some charge every night but only top up a couple of kw) the requirement is spread out further.
I'm deliberately not making the assumption that everyone will charge on the same night. The simple fact would be that we need to power 244 billion vehicle miles per annum in an EV world. I've assumed that the mileage will be evenly distributed on 365 days a year, if you assume that it will be distributed differently, the calculations are far worse. Approaching it this way means that all discussions about granny only doing 2 miles are nugatory - I'm looking at the total mileage and the average power draw. Now try and recalculate for those that would suit the use of an EV. Not everyone will. No one is saying an EV will suit everyone.
How much of that 244 billion is done by cars that will not suit the use of an EV?
AND you're assumption is that everyone will need to charge on the same night, every night. If charging is spread over 7 nights (generally I charge my car only two nights/week, some only charge once/week...some charge every night but only top up a couple of kw) the requirement is spread out further.
Edited by ikarl on Wednesday 20th September 17:25
Yes, these figures are for 100% EV penetration, but only in domestic vehicles. Nothing to do with goods transport (which is probably the same again). If we get 50% penetration, then we only have to build 2 Sizewells, not 3. I am assuming you can't build half a Sizewell. As I said, its not impossible, but we have to get our arses in gear.
One thing I do know, and this is current status, is that there is currently much more generation throughout the country (thousands of MW) that IS connected but not able to export due to a lack of Load on the network. The Transmission grid is currently being upgraded up/down the country to move the power about easier but generation currently on the network far far outweighs the current load requirements.
DELETED: Comment made by a member who's account has been deleted.
The data is all in that report I linked to. Yes, you can pick a date and say "mileage is down" - but the trend over the last decade is up. Mileage declines in recessions. Individual journeys tend to be shorter but more people owning cars = more miles travelled. It would take a rather brave planner to look at the mileage charts in the UK and extrapolate downwards.Where is the efficiency going to come from? Electric motors are already very efficient, as presumably are the power components wired into them. Weight could be a factor, but they're stuffing batteries into these things as fast as possible to get decent range. We're already using light materials and skinny tyres. I suppose we could bin ally and go for titanium, but that is a vast expense.
98elise said:
TA14 said:
98elise said:
Possibly given how much of the global population is uneducated, however his grasp of engineering/physic seems a bit tenuous.
I think he does have a bit of a point about power station capacity though. I remember John Major's government being encouraged to authorise the construction of a new nuclear power station to guarantee a baseline supply. They delayed the decision, as did the Tony Blair government. Even now we're looking at ten years for it to come on line and the French aren't happy with the deal that they've signed. All in all that's the best part of forty years to get one power station built and adding any extra load requirement won't help. (I suppose that you could make the opposite argument and say that if 20 million vehicles would be stranded if the govt doesn't get a move on with power station replacement then that just the kick up the $%^&£ that the govt need)Toltec said:
Some of us included current free capacity or projected renewable capacity or, in my case, what the required supply would be in terms of Hinckley Cs. Oddly all of our estimates fall within one magnitude, Simon's is one or two magnitudes higher than anyone else's.
I am pro-EV, kind of, I want all of the low mileage diesel buyers to swap to them. I also think there is the potential for there to be one that I might want to own one day.
There's a lot to consider re: the coutry's power supply but I get the impression that we need about 3 new nuclear power stations. The answer does depend on how many renewables are built from wind farms to tidal barriers and how many fossil fuel power stations as well as EV's but I'm not sure that EV's would mean any more nuclear power stations, perhaps one. 300 does seem very high, even for a global figure.I am pro-EV, kind of, I want all of the low mileage diesel buyers to swap to them. I also think there is the potential for there to be one that I might want to own one day.
TA14 said:
There's a lot to consider re: the coutry's power supply but I get the impression that we need about 3 new nuclear power stations. The answer does depend on how many renewables are built from wind farms to tidal barriers and how many fossil fuel power stations as well as EV's but I'm not sure that EV's would mean any more nuclear power stations, perhaps one. 300 does seem very high, even for a global figure.
I don't think we'll even need onemore, other than what is already in the pipeline.See my post from the top of this page.
There were approximately 2.6 million new cars registered in the UK in 2016.
The passenger car fleet in the UK is approximately 30M vehicles.
So even if we wanted a totally EV fleet, it would take 11.5 years to actually achieve that, assuming that tomorrow EVERY single car sold was an EV.
What this means is there is almost certainly plenty of time for Generation, Grid, and charging infrastructure to be developed!
The passenger car fleet in the UK is approximately 30M vehicles.
So even if we wanted a totally EV fleet, it would take 11.5 years to actually achieve that, assuming that tomorrow EVERY single car sold was an EV.
What this means is there is almost certainly plenty of time for Generation, Grid, and charging infrastructure to be developed!
Welshbeef said:
Isn't Teslas truck launch very soon?
Be very interesting what that offers - aimed at the USA market so distance will have to be decent which means on our tiny island HGVs will have no range issues. Heck it's going to be great in fact they might actually be brisk to boot
It won't have a significant range on it, but even if you look at the major distribution hubs in the UK, you don't have to go far to cover a whole host of retail points. The Tesla truck would probably focus on low density products though.Be very interesting what that offers - aimed at the USA market so distance will have to be decent which means on our tiny island HGVs will have no range issues. Heck it's going to be great in fact they might actually be brisk to boot
Sure one day it might be an easily solved problem.
Today with our current battery weight and energy density I'm just not sure how you can replace a vehicle that needs several hundred HP for extended (hours) at a time whilst still giving it a decent haulage capacity.
I'm not the only one, check out wrightspeed created by someone who was in at the start of Tesla, they are going hybrid with a clean (turbo sourced) turbine for the extender system, but they struggle with the long haul thing too.
Today with our current battery weight and energy density I'm just not sure how you can replace a vehicle that needs several hundred HP for extended (hours) at a time whilst still giving it a decent haulage capacity.
I'm not the only one, check out wrightspeed created by someone who was in at the start of Tesla, they are going hybrid with a clean (turbo sourced) turbine for the extender system, but they struggle with the long haul thing too.
Paddy_N_Murphy said:
Best solar panels and long rest stops would help ?
Aha like a 4 week rest stop?Cars generally need very little energy to cruise at reasonable speeds and in cities can regen a lot of that back. A car probably needs what 40-50bhp to cruise at 70mph?
https://www.nap.edu/read/13288/chapter/7
"The 21st Century Truck Partnership (21CTP) has identified the areas of energy consumption for a typical Class 8 vehicle operating on a level road at a constant speed of 65 mph with a gross vehicle weight (GVW) of 80,000 lb. In this case, the engine losses are about 322 horsepower (hp)"
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