Electric vehicles miles per KWh

Solarchaser

My Leaf gets about 3.6 miles kwh.

Not noticed any vampire drain, might be because of the inbuilt solar panel for the 12v.

Cost per mile will be whatever the cost of tyres are for the greatest amount.
As its 90% charged at home.
Another 8% say for the free chargers that are all around Scotland.

So for the 2% that's chargeable, I think I'll manage the 10p /mile that generally works out as.

Not moving to export tariff, so the charge from my solar panels is the free it always is, no loss of anything, and no tax subsidy or whatever other phantom charges you can dream up.

As for second hand market, like every car, the value drops after initial purchase then at the 3 year point.
However the second hand market is holding up well, as my 4 year old car is worth more now than when I bought it as a 3 year old car.

GreatApe

Anyway this isn't to say BEVs are a bad technology
They are about equal to internal combustion engines
And they offer the ability to use cheaper coal and gas rather than oil which is a plus
Plus of course in time mass solar and wind too

It's just something I figured out a couple of days ago prior to which I thought it was closer to 25% ICE 50% BEV but no they are both roughly 25% chemical to kinetic

While an electric motor can be nearly 97% efficient that is just one of many steps
Power stations losses, transmission losses, distribution losses, charging losses, AC to DC losses, idle power useage, natural battery discharge, battery pack thermal management even when stationary, DC to AC conversion losses, and the electric motor. Lots of small losses add up to quite a significant 75% or so of the initial chemical energy is losses. If the marginal electricity is coal powered the EVs would clock in at under 20% and perhaps as low as 17% if powered by an old coal plant

1961Nick

GreatApe wrote: »

Quoting myself...this means there is a 40% loss for a typical UK model 3 owner irrespective of where the energy comes from

Grid loss
Charging loss
Standby loss

If charged by a 50% efficient CCGT fleet (as per the UK) you get an overall efficiency of ~30% chemical energy into useable charge in the battery

There are still further losses in the battery DC to AC and then electricity power to motion
Probably looking at less than 25% chemical (coal gas oil) to kinetic energy

Not too dissimilar to petrol or diesel

Of course the advantages is EVs can be nuclear or solar or wind powered
But for now the world's major grids are not clean so for now EVs probably don't reduce fossil fuel burn much at all they just shift it from oil to coal/gas

Even if your figures were correct, the point you’re missing is that the diesel/ petrol fleet emissions are a constant whereas the EV fleet emissions will get cleaner as the grid gets cleaner.

I reckon home charging will become the norm & drivers will choose a vehicle with a range to enable that. Charging away from home or work will be the exception. Drivers covering a lot of miles will use an off peak tariff, whereas those doing small mileages will probably just plug into a regular tariff. Tailored EV tariffs are already being marketed & I expect we’ll soon see many more.

1961Nick

GreatApe wrote: »

Anyway this isn't to say BEVs are a bad technology
They are about equal to internal combustion engines
And they offer the ability to use cheaper coal and gas rather than oil which is a plus
Plus of course in time mass solar and wind too

It's just something I figured out a couple of days ago prior to which I thought it was closer to 25% ICE 50% BEV but no they are both roughly 25% chemical to kinetic

While an electric motor can be nearly 97% efficient that is just one of many steps
Power stations losses, transmission losses, distribution losses, charging losses, AC to DC losses, idle power useage, natural battery discharge, battery pack thermal management even when stationary, DC to AC conversion losses, and the electric motor. Lots of small losses add up to quite a significant 75% or so of the initial chemical energy is losses. If the marginal electricity is coal powered the EVs would clock in at under 20% and perhaps as low as 17% if powered by an old coal plant

.....and every time it’s charged using surplus wind energy during the early hours of the morning, the amount of chemical energy to kinetic energy is nil. Same thing if it’s charged from your own solar power.

GreatApe

1961Nick wrote: »

.....and every time it’s charged using surplus wind energy during the early hours of the morning, the amount of chemical energy to kinetic energy is nil. Same thing if it’s charged from your own solar power.

The UK grid is perhaps as soon as 2024 (just five years away) marignal green so it doesn't quite apply to the UK

But most the world isn't close,
The biggest car market is China which is marginal coal
Second biggest car market USA is marginal coal or gas
The next big block is Europe and the biggest there is Germany which is mostly marginal coal and then gas and will be such for all of the 2020s

That means for most markets a typical use of EVs won't be saving much fossil fuels they will be just shifting demand from oil to coal/gas and mostly coal since China is the biggest car market and it's marignal grid is almost all coal and little NG

There are some big exceptions like France which will be marignal nuclear about 10 months of the year but generally EVs will be coal or NG powered at ~17-25% chemical to kinetic efficiency more or less the same as an ICE

GreatApe

1961Nick wrote: »

Even if your figures were correct, the point you’re missing is that the diesel/ petrol fleet emissions are a constant whereas the EV fleet emissions will get cleaner as the grid gets cleaner.
.

Yes and no
EVs are marginal load
They use marginal generation
So if a grid is say 90% clean 10% coal
If you add more load and the clean elements is fixed then this new load will be 100% coal powered

The UK is now mostly marignal gas so even if the UK grid is 50% wind 50% gas that means the EVs are adding to gas burn in power stations. Of course it varies from day to day and hour to hour. For instance some windy nights we are indeed marginal nuclear powered (that means an additional large load would be powered by marignal french nuclear imports)

But mostly we are marignal gas

But anyway the big markets are China USA both of which are almost always marignal coal/gas likewise much of Europe is still marginal coal or gas like Germany Poland and others

Simply put the reality is that BEVs are similar chemical to kinetic efficiency Vs efficient oil cars
And most the worlds grids are marginal coal or gas

Martyn1981

1961Nick wrote: »

Even if your figures were correct, the point you’re missing is that the diesel/ petrol fleet emissions are a constant whereas the EV fleet emissions will get cleaner as the grid gets cleaner.

Share of coal in UK's electricity system falls to record lows

Dr Iain Staffell, of Imperial College London, said: “An electric vehicle in the UK simply cannot be more polluting than its petrol or diesel equivalent – even when taking into account the upfront carbon cost of manufacturing their batteries. Any EV bought today could be emitting just a tenth of what a petrol car would in as little as five years’ time, as the electricity it uses to charge comes from an increasingly low-carbon mix.”

JKenH

1961Nick wrote: »

Even if your figures were correct, the point you’re missing is that the diesel/ petrol fleet emissions are a constant whereas the EV fleet emissions will get cleaner as the grid gets cleaner.

I reckon home charging will become the norm & drivers will choose a vehicle with a range to enable that. Charging away from home or work will be the exception. Drivers covering a lot of miles will use an off peak tariff, whereas those doing small mileages will probably just plug into a regular tariff. Tailored EV tariffs are already being marketed & I expect we’ll soon see many more.

I don’t think it is true that diesel/petrol fleet emisssions are constant. There has been a continual tightening of ICE emissions regulations and this is continuing. The latest testing regime is having a significant impact on real world emissions after the dieselgate scandal so I believe we will see cleaner ICE fleets ( but not necessarily more economic vehicles). As the older vehicles leave the fleets they pass into the hands of motorists who on average are doing lower mileages so total ICE emissions will fall.

There is pressure to increase the provision of workplace charging points with tax breaks for employees and this may well lead to a change in charging habits for those who are lucky enough to have free charging at work. As EV performance is reduced in winter (colder weather, increased use of lights, wipers, heaters etc) the demand on the grid during the working day will increase. There is a possibility therefore that the EV fleet emissions may in the short term get dirtier.

Martyn1981

GreatApe wrote: »

An EV is about 25% chemical energy in a power station to motion
An oil car is about 25% chemical energy in a tank to motion

I used diesel so it's a direct comparison and I said you could use the same thermal energy of natural gas if you like (or even coal)

An EV may indeed be about 70% efficient when moving, but the point of this thread is to highlight it's 0% efficient when not moving. The two averaged together drags this headline 70% (or whatever) further down


Going back to the math again
Assume an EV has idle annual energy use of 500KWh to keep it a round figure
Assume an EV does the average 7,100 miles for 1,730KWh (so 4.1 miles per kWh)
The total combined is an annual 2,230KWh
Assume grid loss of 8% and charge of 15% you get 2,850 KWh at the power station

That is to say an EV with a headline figure of 4.1 miles per KWh actually in this example is getting 2.5 miles per KWh (as measured at the power station)

And since most the world is still marginal coal gas or oil these EVs are indirectly powered by coal gas and oil.


If Gas/Oil fired nation at 50% efficiency works out to 1.25 miles per KWH thermal
If Coal powered nation at 40% efficiency works out to 1 mile per KWh thermal

By comparison this telsa model 3 is also roughly 1.25 miles per KWh

That is to say they use about as much primary energy as a good diesel if the nation is gas or oil marignal and more primary energy if coal


Re your point it takes energy to refine crude
Well it takes energy to mine move and crush coal into a power
It takes energy to drill clean pump liquify pipe compress NG

Your whole argument is bogus.

The grid leccy mix is falling FF, and rising RE. The rate at which FF's are being pushed off the grid is around 3%pa, probably around 10x greater than the additional demand from BEV's.

So, in marginal terms, all additional BEV's are now powered from the additional generation from RE, whilst the 'old' demand and supply is also slowly moving from FF to RE.

So, the true question, yet again, comes back to this -

Why, when we have a motoring forum, and extensive EV discussions on there, would you create a thread on the Green & Ethical Board to promote diesel over BEV's?

As with all your new threads, this one also appears to be nothing more than a 'vehicle' (see what I did there?) for your campaign against RE, AGW and FF emissions.

1961Nick

GreatApe wrote: »

Yes and no
EVs are marginal load
They use marginal generation
So if a grid is say 90% clean 10% coal
If you add more load and the clean elements is fixed then this new load will be 100% coal powered

The UK is now mostly marignal gas so even if the UK grid is 50% wind 50% gas that means the EVs are adding to gas burn in power stations. Of course it varies from day to day and hour to hour. For instance some windy nights we are indeed marginal nuclear powered (that means an additional large load would be powered by marignal french nuclear imports)

But mostly we are marignal gas

But anyway the big markets are China USA both of which are almost always marignal coal/gas likewise much of Europe is still marginal coal or gas like Germany Poland and others

Simply put the reality is that BEVs are similar chemical to kinetic efficiency Vs efficient oil cars
And most the worlds grids are marginal coal or gas

Due to the likely charge times for EVs (00.00 - 05.00), it's probable that any future 'greening' of the grid will multiple effect on the marginal element used for EV charging.