BEV emmissions

almillar

7,500 miles/Yr @ 4.2m/kWh = 1786 units

That's more m/kWh than I get year round. I'm on 3.8 after 2 years (2 summers and 2 winters).

1.1KWh/d self discharge = 402 units

We've talked about this before. Totally overblown. EVs do NOT lose 1kWh in a day, just sitting there. Maybe you've got an extreme case with a Tesla with all the bells and whistles like Sentry Mode running, but this is absolutely not representative, and if you can't measure it, leave it out.

Annual winter heating = 200 units

Again, did you make this figure up? Any power used to heat the car, is already included in the year round m/kWh figure. Removed.

Here it is with my figures:

7,500 miles/Yr @ 3.8m/kWh = 1973 units
Charging efficiency 85% = 2321 units out of your socket (I think my 7kW charger is more efficient than this, and I think Rapid chargers are too, but I'll leave it).
Works out to 3.23 miles per KWH

407g/KWh / 3.23 miles/kWh / 1.6 to convert miles to km = 79 grams / km


I'm taking all your Gas figures at face value.
That's a significant reduction on a 100g/km car.

When you plug in a Tesla into a super charger and pull 250KW from the grid that's 250KW more from a gas station chucking more methane into the turbine

Where on earth does all the renewable energy go, if 100% of the electric in a Tesla is fossil fueled?

silverwhistle

almillar wrote: »

Again, did you make this figure up?

I think it's even more random than that! Which is why many don't waste time responding any more...

ABrass

I haven't read most of the thread, but based on the title this is probably pertinent.

https://cleantechnica.com/2019/12/16/latest-report-claims-emissions-from-lithium-ion-battery-production-much-lower-than-two-years-ago/

This month, IVL updated its findings from 2017 in light of current experience and found carbon emissions from making lithium-ion batteries are much lower today than they were two years ago. The biggest factor in the decline in emissions is the source of electricity used in the manufacturing process. Today, carbon emissions from battery manufacture range from a low of 61 kilograms per kilowatt-hour to a high of 106 kilograms per kilowatt-hour.

GreatApe

almillar wrote: »

That's more m/kWh than I get year round. I'm on 3.8 after 2 years (2 summers and 2 winters).

Thanks
Can you confirm your mileage in those two years and if it's mostly urban or motorway

Again, did you make this figure up? Any power used to heat the car, is already included in the year round m/kWh figure. Removed.

I didn't make it up I estimated it by taking a power figure and the number of hours in the winter the heating would be on this is for ore heat as well as maintaining cabin temp.

Here it is with my figures:

7,500 miles/Yr @ 3.8m/kWh = 1973 units
Charging efficiency 85% = 2321 units out of your socket (I think my 7kW charger is more efficient than this, and I think Rapid chargers are too, but I'll leave it).
Works out to 3.23 miles per KWH

407g/KWh / 3.23 miles/kWh / 1.6 to convert miles to km = 79 grams / km

Thanks again.
It would be nice to have actual figures from a hundred+ EV drivers
The best method would be to have an actual meter behind the charger so we don't have to guess the losses of the charger etc

I'm taking all your Gas figures at face value.
That's a significant reduction on a 100g/km car.

The ICE is about 106g/km
If you are getting the figures you say and the 85% charger efficiency is correct and it works out to 79g/km that indeed is a saving of 25% over an ICE

It will be less over its lifetime as there Re 300kg or so more materials in a BEV than a hybrid

And this is in a gas marginal grid, most the world is coal marginal or a mix of coal and gas marginal. Especially the biggest grid in the world is almost fully coal marginsl

Where on earth does all the renewable energy go, if 100% of the electric in a Tesla is fossil fueled?

Re emmissions it makes sense to treat marginal demand as adding to marginal supply
In the same way that marginal new supply (say a new wind farm) displaces marginal Coal/gas generation rather than the average mix

JKenH

GreatApe wrote: »

Re emmissions it makes sense to treat marginal demand as adding to marginal supply
In the same way that marginal new supply (say a new wind farm) displaces marginal Coal/gas generation rather than the average mix

Right, I understand now why you are regarding charging a BEV as marginal demand even when using solar via a Zappi.

I had been looking at it from the short term point of view where the grid is ticking over at 40Mw and I plug my BEV in. Whether I switch my kettle on or plug in my BEV that produces marginal demand.

My point was, however, that if my BEV is being charged on solar via a Zappi then the marginal demand is met by the sun emerging from behind a cloud not a CCGT.

Martyn1981

JKenH wrote: »

Right, I understand now why you are regarding charging a BEV as marginal demand even when using solar via a Zappi.

But you also have to compare those CCGT emissions (CO2 and pollution) directly against the ICE emissions, and all of the emissions in the ICE fuel supply chain. And all of the leccy generation emissions for the refinery too, approx 6kWh/gallon.

BUT (big but), BEV's will mostly charge at night, and can use multiple forms of smart charging (such as the Zappi you mention) going forward. This means that they enable the deployment of more RE, and help to allow a greater % penetration of RE into the leccy mix, especially now as we go forward, and can expect greater periods of excess RE generation.

So not only are BEV's lower CO2 than ICE, lower emissions than ICE, infinitely lower localised pollution than an ICE, but they are also part of the solution to lowering all leccy emissions ....... something ICEV's can not and will not ever do.

ABrass

The marginal argument only holds at the micro level, not the macro. Adding a single EV to the system results in more draw at a point in time, which might be wind that'd otherwise be curtailed, or gas that has to fire up.

But add enough to need more power and the argument falls apart. Then you'd have to look at what generation is likely to be added to the grid to supply it. Does anyone know what the ratio of fossil to renewable energy has been added to the grid in the last few years?

Martyn1981

ABrass wrote: »

The marginal argument only holds at the micro level, not the macro. Adding a single EV to the system results in more draw at a point in time, which might be wind that'd otherwise be curtailed, or gas that has to fire up.

But add enough to need more power and the argument falls apart. Then you'd have to look at what generation is likely to be added to the grid to supply it. Does anyone know what the ratio of fossil to renewable energy has been added to the grid in the last few years?

In short, RE capacity is growing, whilst FF capacity is falling. For more detail take a look at page 29 for capacity changes from 1996-2018, and page 8 for a quick Q1 generation comparison.

[Edit - Coal capacity is within the 'conventional steam' category. M.]

I believe that these will knock your socks off unless you are in significant denial.


Further edit - probably worth putting some numbers down for easier reading, so from 1996-2018,

FF generation has fallen from ~56GW to ~50GW, but note it peaked at 71GW in 2010.

Nuclear has fallen from ~13GW to ~9GW.

Non hydro renewables have grown from ~2GW to ~44GW, but note the vast bulk in growth is since 2010, when we (and the World) started to take them more seriously.

For a 2010+ breakdown we then see capacity of FF's fall from 71GW to 50GW, nuclear fall from 11GW to 9GW, and RE grow from 9GW to 44GW.

[Bear in mind capacity factors, so we can't compare capacity directly, but we can use additions/reductions to draw conclusions.]

GreatApe

JKenH wrote: »

Right, I understand now why you are regarding charging a BEV as marginal demand even when using solar via a Zappi.

I had been looking at it from the short term point of view where the grid is ticking over at 40Mw and I plug my BEV in. Whether I switch my kettle on or plug in my BEV that produces marginal demand.

My point was, however, that if my BEV is being charged on solar via a Zappi then the marginal demand is met by the sun emerging from behind a cloud not a CCGT.

If you are grid connected the marginal demand is whatever power station kicks in to add the supply

The only instance this can be a wind farm or solar panel is if it's being curtailed and the additional EV demand allows the curtailment to be scaled back. So about 2% of the hours in a month marginal demand is met by curtailed wind power. So about 2% of the time charging your EV is 100% wind power. The other 98% of the time it's 100% CCGT. This is true of you have solar panels or if you don't

Now if you are not grid connected and your solar is being curtailed then your EV is indeed 100% solar. Or if you live in a nation which has so much solar it is being curtailed so plugging in your EV results in the nation not curtailing (but this doesn't exist anywhere afaik)

The mix of power doesn't matter
That a house has solar doesn't matter
Proximity to the house doesn't matter.
Whatever station has to step in to provide the power is the emmissions

GreatApe

ABrass wrote: »

The marginal argument only holds at the micro level, not the macro. Adding a single EV to the system results in more draw at a point in time, which might be wind that'd otherwise be curtailed, or gas that has to fire up.

But add enough to need more power and the argument falls apart. Then you'd have to look at what generation is likely to be added to the grid to supply it. Does anyone know what the ratio of fossil to renewable energy has been added to the grid in the last few years?

The marginal load being supplied by the marginal generator will always be true

In the UK we are about 98% of the time marginal gas the other 2% of hours marginal wind

We already have a very significant amount of wind power but are only marginal wind 2% of the time

Adding a lot of wind doesn't hugely increase the times hours when it's marginal wind

So yes this 2% will increase but not by much and not anytime soon

Especially taking into account the actual future of the UK grid where half the reactors are closing 2023/4 so for the next 4 years we are taking two steps forward then two steps back. The additional interconntors should lower wholesale prices by a small amount but they will also lower the marginal wind times by a larger amount

Overall what you say is true but only very very slowly
Certainly all of the next decade will be marginal gad almost all the time this 98% v 2% ratio won't change to more than 95% v 5% by 2030 so EV indirect emmissions will get about 3% cleaner over a decade of that