Electric cars

Joe_Horner

IanMSpencer wrote: »

That tells me that the supply infrastructure is not robust and is probably reliant on people spreading the load. If households are charging their 2 (or more) cars and with larger ranges charging for longer or faster, then I'd want the National Grid official view on whether the infrastructure is designed to cope with the change in load. We did have an XMas afternoon power cut for example.

The simple answer to that is that, without either a quantum change in technology or a massive change of habits, it wouldn't cope with full electrification of transport.

The government's estimates for road miles in 2016 are:

cars / taxis 252 billion miles

• LGV 49 billion miles
• HGv 16.6 billion miles
• Busses 2.6 billion miles.

If we're very generous and allow:

• cars / taxis average 4 miles per kWh
• LGV average 3 miles / kWh
• HGv / busses average 2 miles per kWh

that gives a total energy requirement of 88.9 billion kWh, or 88.9 terrawatt hours, for current transport use patterns. Which is roughly the same demand as all UK industry combined in 2016.

The government's Digest of Energy Statistics chapter 5 (electricity) gives a total UK consumption in 2016 of 303 tWh.

So, electrifying all transport with unrealistically efficient (using current tech) vehicles, would create a roughly 30% average increase in continuous demand on the grid and generation. We simply don't have that much reserve capacity, and never have had. At peak times, when everyone gets home and starts charging it's gionna get messy......

Finally, for those espousing the "efficiency of electricity". It's worth noting from tose official statistics that the energy losses (including energy used by the energy industry) suffered in generating and distributing the current 303 tWh demand are estimated at 457.2 tWh. Which is only about 40% efficiency even before local losses in the vehicles.

Martyn1981

Joe_Horner wrote: »

Finally, for those espousing the "efficiency of electricity". It's worth noting from tose official statistics that the energy losses (including energy used by the energy industry) suffered in generating and distributing the current 303 tWh demand are estimated at 457.2 tWh. Which is only about 40% efficiency even before local losses in the vehicles.

Please don't be so silly. The losses are not 457TWh, you are confusing the gross fuel to output figures, with distribution losses.

Your own link shows that generation is approx 336TWh, so losses are around 10%.

What you are trying to sell as a loss, is the inefficiency of converting coal or gas into leccy, which is around 30-50% efficient.

As explained earlier, the efficiency of gas generation to leccy for transport is actually more efficient than petrol and diesel engines, so you have, somewhat unwittingly, confirmed the inefficiences of burning FF's, not the leccy infrastructure.

More importantly, ICE cars and other transport are 100% FF powered and always will be, whereas grid charged EV's are now only 50% FF powered, and the percentage goes down every year.

[Edit - Just for fun, consider this. We could take all the petrol and diesel and burn it at a thermal powerstation, where it would be approx 50% efficient, and then distribute it to the grid at 10% losses, taking the 50% down to 45%.

45% is still more efficient than the cars and trucks will achieve, and would be cleaner due to the scrubbers at the power station. So this would solve the issue of more generation being needed. but as I say, just for fun, and just to show how idiotic it is, when you think about it, for every vehicle to have it's own small FF engine. M.]


Back to your figure of a 30% increase in leccy demand, please be reminded (yet again) of the large electrical demand that the refinery industry has, typically supplied directly from coal burning power stations. So the actual net increase will be more like 15%-20%.

Joe_Horner

Martyn1981 wrote: »

Please don't be so silly. The losses are not 457TWh, you are confusing the gross fuel to output figures, with distribution losses.

Your own link shows that generation is approx 336TWh, so losses are around 10%.

What you are trying to sell as a loss, is the inefficiency of converting coal or gas into leccy, which is around 30-50% efficient.

Err, the energy lost "through inefficiency" IS PART OF THE LOSS. That's what inefficiency means[i/] !!!!!!!!! You can't just pick the part of the energy cycle that suits you and say "Look!!! 100% efficient!!!!" because that's cheating*.

It's also a strawman suggesting that I declared them as "distribution losses" when I very clearly stated "generation and distribution losses".

Back to your figure of a 30% increase in leccy demand, please be reminded (yet again) of the large electrical demand that the refinery industry has, typically supplied directly from coal burning power stations. So the actual net increase will be more like 15%-20%.

The refinery industry is - one would assume from the fairly unambiguous wording - included in the figure for "all other industry". Unless you're suggesting that the refinery industry isn't an industry?

Given that the enormously energy intensive steel industry warrants it's own entry at 2.8 tWh, it's probably safe to place the refinery industry at less than that.

So, you may be able to offset the 89 tWh by 3 tWh from refineries - in case you haven't noticed I'm being generous in your favour yet again. But that still leaves an increase of 28% on annual demand . Which we don't have existing capacity for.






* Although it's exactly the type of cheating that's used to say "look how low emission my electric car is" because the emissions happen elsewhere instead.

AdrianC

Of course, oil refineries won't just shut down overnight and cease to exist...

Oil products are used for a LOT of other things in this world - and the whole of one barrel of crude can't be used for petrol OR diesel OR plastic OR heating oil OR bitumen.

Joe_Horner

AdrianC wrote: »

Of course, oil refineries won't just shut down overnight and cease to exist...

Oil products are used for a LOT of other things in this world - and the whole of one barrel of crude can't be used for petrol OR diesel OR plastic OR heating oil OR bitumen.

They'll be needed to supply all those power stations we have to build in a hurry.... :rotfl:

zeupater

Joe_Horner wrote: »

The simple answer to that is that, without either a quantum change in technology or a massive change of habits, it wouldn't cope with full electrification of transport.

The government's estimates for road miles in 2016 are:

cars / taxis 252 billion miles

• LGV 49 billion miles
• HGv 16.6 billion miles
• Busses 2.6 billion miles.

If we're very generous and allow:

• cars / taxis average 4 miles per kWh
• LGV average 3 miles / kWh
• HGv / busses average 2 miles per kWh

that gives a total energy requirement of 88.9 billion kWh, or 88.9 terrawatt hours, for current transport use patterns. Which is roughly the same demand as all UK industry combined in 2016.

The government's Digest of Energy Statistics chapter 5 (electricity) gives a total UK consumption in 2016 of 303 tWh.

So, electrifying all transport with unrealistically efficient (using current tech) vehicles, would create a roughly 30% average increase in continuous demand on the grid and generation. We simply don't have that much reserve capacity, and never have had. At peak times, when everyone gets home and starts charging it's gionna get messy......

Finally, for those espousing the "efficiency of electricity". It's worth noting from tose official statistics that the energy losses (including energy used by the energy industry) suffered in generating and distributing the current 303 tWh demand are estimated at 457.2 tWh. Which is only about 40% efficiency even before local losses in the vehicles.

Hi

You've done a decent job of attempting a double accounting exercise there, but here's an example of what should have been done to 'rescale' the conclusion to something less sensational ...

.... If refining petrol/diesel consumes 6kWh of electricity/gallon (imperial) and each of these gallons contains 47kWh(your previous figures extrapolated) of combustible energy which when converted to traction energy at 30% efficiency, the traction energy equivalent is 14kWh/gallon .. subtract the 6kWh (Martyn1981's previous figure) embedded electricity from the refining stage and each gallon combusted adds a net 8kWh of traction energy to one side of the equation, thus 17% overall efficiency (8/47) before motion/transport inefficiencies are accounted for ...

On the other side of the equation, taking a geographically distributed low carbon source of electricity generation (ie low distribution losses) we get very little in the form of losses ... to keep things simple let's just say that ICE vehicle engine idling, starting etc inefficiencies equate to transmission & storage losses and we're left with a ratio of around 100:17, which is pretty significant.

So, what does the ratio of 100:17 mean in terms of the 88.9TWh of transport requirement according to your proposed figures in the above post? ... well, it means that even if there was currently absolutely no spare generating capacity at all in the UK, the equivalent to the 88.9TWh of energy contained in diesel would be delivered by just over 15.1TWh ((88.9/100)*17) of additional electricity generated over a year ... spread evenly (24x365) it's the equivalent of ~1.7GW of additional generation capacity, well under 5% of what we currently have ... In Anglesey terms, about 1/2 of the average generation of the proposed 3 developments mentioned a couple of posts ago ...

Of course, charging demand will vary and this becomes the obvious retort to the above conclusion, but this is so easily countered by the realisation that overall energy demand across all sources does also ... that's why there's surplus capacity every night and at weekends - it's just a case of smoothing demand to balance to available supply (and probably adding a little additional capacity - 10%(?)) - obviously, this will likely be managed primarily by time of use tariffs to encourage overnight & weekend charging for those who can ...

Overall, not such a gloomy picture as that first painted.

HTH
Z

welfayre

This story just popped up on my fb feed for anyone interested.

https://cleantechnica.com/2018/01/01/shenzhen-completes-switch-fully-electric-bus-fleet-electric-taxis-next/amp/

(Google Shenzhen electric buses for other articles).

All in all the city has moved 16500 buses from diesel to electric along with installing 8000 street lamp chargers (that can be used by cars too) and 300 bus charging stations. They also plan to switch over 12000+ taxis by 2020. The article doesn't mention the full cost it does say the city spent $500million on the scheme on 2017 alone but even if they've been doing it for 20 years it would still be less than half the cost of estimated cost of HS2. It also doesn't state how the electricity is generated but does say the switch will save 1.35million tonnes of carbon emissions per year.

I realise that it's just one city and that there would be additional problems rolling out electrification on a national level but it does go to show that the large scale implementation of electric vehicles (large electric vehicles at that) is possible with a bit of foresight and planning. Imo the biggest problem facing Electrification in the U.K. is our inept central and local governments more than any technical issue.

All that said I've still not worked out why people think switching from one finite natural resource that causes environmental damage when extracted and pollution when used to another finite natural resource that cause environmental damage (maybe even more) and radioactive waste when processed to power our transport is such a great idea? Maybe it just because the damage will be far away from them they don't consider it such an issue.

Joe_Horner

zeupater wrote: »

Hi

You've done a decent job of attempting a double accounting exercise there, but here's an example of what should have been done to 'rescale' the conclusion to something less sensational ...

.... If refining petrol/diesel consumes 6kWh of electricity and each gallon (imperial) contains 47kWh(your previous figures extrapolated) of energy which when converted to traction energy at 30% efficiency, the traction energy equivalent is 14kWh/gallon .. subtract the 6kWh (Martyn1981's previous figure) embedded electricity from the refining stage and each gallon combusted adds 8kWh of traction energy to one side of the equation, thus 17% overall efficiency (8/47) before motion/transport inefficiencies are accounted for ...

On the other side of the equation, taking a geographically distributed low carbon source of electricity generation (ie low distribution losses) we get very little in the form of losses ... to keep things simple let's just say that ICE vehicle engine idling, starting etc inefficiencies equate to transmission & storage losses and we're left with a ratio of around 100:17, which is pretty significant.

So, what does the ratio of 100:17 mean in terms of the 88.9TWh of transport requirement according to your proposed figures in the above post? ... well, it means that even if there was currently absolutely no spare generating capacity at all in the UK, the equivalent to the 88.9TWh of energy contained in diesel would be delivered by just over 15.1TWh ((88.9/100)*17) of additional electricity generated over a year ... spread evenly (24x365) it's the equivalent of ~1.7GW of additional generation capacity, well under 5% of what we currently have ... In Anglesey terms, about 1/2 of the average generation of the proposed 3 developments mentioned a couple of posts ago ...

Of course, charging demand will vary and this becomes the obvious retort to the above conclusion, but this is so easily countered by the realisation that overall energy demand across all sources does also ... that's why there's surplus capacity every night and at weekends - it's just a case of smoothing demand to balance to available supply (and probably adding a little additional capacity - 10%(?)) - obviously, this will likely be managed primarily by time of use tariffs to encourage overnight & weekend charging for those who can ...

Overall, not such a gloomy picture as that first painted.

HTH
Z

Err, no. The calculations in my previous were done entirely based on electric vehicles and the electrical energy required by them at "point of delivery" . That 88 tWh requirement isn't based on fossil fuel use. It's based directly on (very generous) numbers for EV battery range.

For cars, 4 miles per kWh equates to 400 miles from a 100kWh battery, which is quite generous with today's tech.

For LGV, allowing 3/4 of car efficiency seems reasonable but the actual figure is still generous because it's based on a generous car figure.

For HGVs and busses, allowing 2 miles per kWh - or 200 miles on a 100kWh battery - is ludicrously high efficiency but their total mileage is (relatively) small at only around 18 billion miles combined so I thought I'd be generous.









eta: Just looked back and saw that I skimped on my workings, which may have confused you. It goes like this:


cars / taxis 252 billion miles @ 4 miles per kWh of electricity = 63 billion kWh
LGV 49 billion miles @ 3 miles per kWh of electricity = 16.3 billion kWh
HGv 16.6 billion miles @ 2 miles per kWh of electricity = 8.3 billion kWh
Busses 2.6 billion miles @ 2 miles per kWh of electricity = 1.3 billion kWh

total = 88.9 billion kWh = 88.9 tWh of electricity.

Joe_Horner

Incidentally, just a couple of fun facts to lighten the mood.

Petrol and diesel have around 7 times more energy per kg than dynamite.

Dried cow or camel dung has around 20 times more energy per kg than current Tesla batteries.

zeupater

Joe_Horner wrote: »

Err, no. The calculations in my previous were done entirely based on electric vehicles and the electrical energy required by them at "point of delivery" . That 88 tWh requirement isn't based on fossil fuel use. It's based directly on (very generous) numbers for EV battery range.

For cars, 4 miles per kWh equates to 400 miles from a 100kWh battery, which is quite generous with today's tech.

For LGV, allowing 3/4 of car efficiency seems reasonable but the actual figure is still generous because it's based on a generous car figure.

For HGVs and busses, allowing 2 miles per kWh - or 200 miles on a 100kWh battery - is ludicrously high efficiency but their total mileage is (relatively) small at only around 18 billion miles combined so I thought I'd be generous.









eta: Just looked back and saw that I skimped on my workings, which may have confused you. It goes like this:


cars / taxis 252 billion miles @ 4 miles per kWh of electricity = 63 billion kWh
LGV 49 billion miles @ 3 miles per kWh of electricity = 16.3 billion kWh
HGv 16.6 billion miles @ 2 miles per kWh of electricity = 8.3 billion kWh
Busses 2.6 billion miles @ 2 miles per kWh of electricity = 1.3 billion kWh

total = 88.9 billion kWh = 88.9 tWh of electricity.

Hi

Whatever you're attempting to convey & however you're calculating for comparison, you need to make allowance for two major elements ... the relative traction delivery efficiency -and- the embedded energy from the refining process needs to be netted off ... you simply can't compare the total combustible energy potential of a volume of refined fuel with the traction energy potential of stored electricity - To make a direct comparison it must be (total fuel energy to create ICE traction+energy to refine ICE traction) vs (total energy to create EV traction-energy to refine equivalent ICE traction)

HTH
Z