Battery Electric Vehicle News / Enjoying the Transportation Revolution

JKenH

orrery said:

JKenH said:

Quite simple really. Your panels are sending electricity to the grid for everyone to use to boil their kettles, charge their cars run their ASHPs, light their schools offices and factories. Once you plug your car in that electricity that your panels had been providing has to come from somewhere else...

What a strange view, you seem to admit the merit of my argument and then say, yebut arbut, when you turn it off ...

Your argument is pointless: we progressively add more renewables and therefore we get nearer to zero emissions, and we already know that the 100% coal fired EV starting point was better that ICE.
ICE fuel is a dirty filthy business (ref the video) and we're moving away from it. Every step we take along the path is a win, but still those following the Oil Company playbook (ex tobacco company playbook) still pop up trying to throw in obscure arguments to sow doubt, then others repeat it.

So, in the meantime, I use either pure 100% solar ('cos my charger can do that) or I charge overnight using leccy from my 100% renewables tariff (don't bother, we've done that one to death too).

Well, you are entitled to view the world the way you want to see it. I know many others look at it just like that but that still doesn’t make it correct. 

But let’s have a look at the last sentence of your post that you charge overnight using leccy from your 100% renewables tariff. (I don’t know who your supplier is but I charge on Octopus Go Faster overnight which also claims to be 100% renewables). You go on to suggest we shouldn’t discuss that because it’s been done to death. But as you raised it maybe we should just have a look at it.

This argument all stems from comments I made on 29th March after a week or so of very low wind. Now I accept that is unusual but it does throw up a problem for your claim that your (our) tariff is 100% renewables.



if you look at the screenshot above you will see renewables (wind and solar) were producing just 4.3% of our electricity in the early hours (basically around this amount for the whole of the cheap tariff period for several days). 

At the end of September 2021 Octopus had 3.1m of a total 28m electricity customers which is around 11%. (It’s probably quite a few more now after so many other companies collapsed). As many Octopus customers would be charging their cars at cheap rate (and according to most contributors here they do) you might expect Octopus’s share of the demand at that time might be even higher than 11%. If we assume 11% though then Octopus customers would be using around 3.5GW when just 1.07GW of renewable electricity was being generated. Now some people call biomass renewable - I don’t - but even if you use that there is still not enough renewable energy being generated to supply even Octopus customers, let alone the other companies that say that 100% of their electricity is from renewables. 

So while you are happy that you are using 100% renewable electricity for all your car charging the reality on occasions may be a little different. 

1961Nick

My observations of Gridwatch is that marginal generation is almost always the highest CO2 - coal, OCGT, CCGT It's therefore reasonable to conclude that since the overnight demand is half of the daytime peak, charging an EV overnight will account for less CO2 than charging it during the day.

The energy mix for March has been skewed by a lack of wind, a wholesale gas price over 250p/therm & a war. According to my app, the carbon impact of charging my car during March was more than double the lifetime average.

silverwhistle

JKenH said:

Quite simple really. Your panels are sending electricity to the grid for everyone to use to boil their kettles, charge their cars run their ASHPs, light their schools offices and factories. Once you plug your car in that electricity that your panels had been providing has to come from somewhere else.

Given that argument I might as well plug in my car at any old time because you say the displacement effect happens willy-nilly. Effectively you are saying that plugging in when I am producing doesn't make any difference to the above effect? A lot of companies are putting a fair bit of effort into shaping consumer demand to flatten peaks and match demand to production. Perhaps you should tell them that they are wasting their time. 

Spies

The Stellantis cars worth looking at even with their relatively poor efficiency? They charge at 100kw so that does that make up for the shortcomings? 

Magnitio

Spies said:

The Stellantis cars worth looking at even with their relatively poor efficiency? They charge at 100kw so that does that make up for the shortcomings? 

It depends on the types of journey that you do and where you buy your energy. If you do lots of long journeys and are time-constrained, then a fast charge rate may be more important. However, fast charging is generally more expensive, inefficient and can add to battery degredation. Also note that the 100kw is peak charge rate in ideal conditions (temperature, state of charge and availability of power at the charging station.) If most journeys are easily within the range of the car, then efficiency is far more important, saving energy and cost.

michaels

Spies said:

The Stellantis cars worth looking at even with their relatively poor efficiency? They charge at 100kw so that does that make up for the shortcomings? 

On one of the websites was a calculator that showed 'real world' ranges - a '205' mile ecorsa would only get about 100 miles at motorway speeds in the cold at most - less in the wet and wind.  I know of people who find the range very limiting.

JKenH

silverwhistle said:

JKenH said:

Quite simple really. Your panels are sending electricity to the grid for everyone to use to boil their kettles, charge their cars run their ASHPs, light their schools offices and factories. Once you plug your car in that electricity that your panels had been providing has to come from somewhere else.

Given that argument I might as well plug in my car at any old time because you say the displacement effect happens willy-nilly. Effectively you are saying that plugging in when I am producing doesn't make any difference to the above effect? A lot of companies are putting a fair bit of effort into shaping consumer demand to flatten peaks and match demand to production. Perhaps you should tell them that they are wasting their time. 

Well yes and no. Let’s try and make this a little more nuanced.

Before we deal with the yes and no, let me clarify what I am sure we all understand - just one individual plugging in their kettle or even their car will not on its own instantaneously require a reaction from the grid in turns of ramping up generation, nor will one individual turning off a kettle or car impact the grid. There are literally millions of people making these micro changes to demand all the time and these micro changes balance each other out to an extent. There is also inertia in the grid so the turbines keep spinning without affecting grid frequency when there are small demand changes. Obviously we will cumulatively eventually reach a point at which the grid has to respond with either more or less generation and the grid tries to anticipate this.

So when I talk about an individual plugging in their car and the impact on the grid I am talking figuratively. One individual’s action on its own in terms of either generation or consumption does not immediately impact the grid but cumulatively we do. Whilst the grid cannot predict our individual random behaviour it can predict what millions of us will do en masse. 

Now at this point you may say if what I do as an individual doesn’t impact the grid because of its inertia then I can’t make any impact on CO2 either one way or the other but in that case it doesn’t matter whether you charge your car from solar or coal - neither would have impact on CO2 emissions. If that were the case then we could all sleep with a clear conscience.  If we argue that then we must also accept that the solar panels on our individual roofs have no impact on the grid so are pointless beyond cutting down our individual electricity bills and collecting FiT. That is certainly not my point of view but you can’t have one without the other. 

So you will understand that when I say every time you plug your car in we are taking about a collective you - a sufficient number that it impacts the grid and causes a change in generation and CO2 emitted.

Now we can turn to the yes and no.

Yes  (in response to the first two sentences of your post)- when you (the collective you) plug your car in at anytime it impacts on the grid, just as your (collective) solar  panels impact on the grid. So on a nice sunny day when your  panels are producing, your own and your neighbours electricity is being generated from a certain mix of solar, wind, nuclear, biomass and gas etc. When something extra is plugged in to the grid that necessitates the grid to respond then wind and solar can’t respond (they are running at full capacity) so all the extra demand is met by the marginal generation available, usually CCGT or OCGT. Hence plugging your (collective) car in even on a sunny day causes more CO2 to be emitted.

No (in response to the last two sentences of your post) - I did say in a previous post (subsequent to the one you have just quoted) that “I believe something like a Zappi car charger or  iBoost/Eddi solar diverter can smooth out the peaks and troughs of demand/supply particularly on a day like yesterday when most of us I think had bands of cloud/rain/snow scudding across our roofs.”

With a Zappi you are responding immediately to very short term localised changes in generation that could impact on local grids smoothing out those peaks and troughs. You are supply following much quicker than the grid can respond and effectively soaking up those short bursts of solar power that would be lost in the inertia of the grid. That situation is though very different to us all plugging our cars in on a sunny windless day. On those sunny windless days as there is nowhere near enough solar to meet demand when the collective we/you plug in our cars, we add to the overall level of demand and hence the amount of gas being burnt and the CO2 generated. At 3pm on 29th March we were burning 21 GW of gas while the sun was shining and 2GW of coal compared with around 14GW of gas and 0.25 GW of coal at 3am that morning. Plugging our cars in then would have been bad for the grid as only the dirtiest generation could respond. The previous day had more solar but even so at peak solar (5.8GW) at 1pm we were burning 19.4GW of gas and 1.8 GW of coal. 

So if you want to help the grid match demand to production it is better to charge overnight as @Nick1961 suggested and let the solar generated during the day meet time critical demand. 

Martyn1981

silverwhistle said:

JKenH said:

Quite simple really. Your panels are sending electricity to the grid for everyone to use to boil their kettles, charge their cars run their ASHPs, light their schools offices and factories. Once you plug your car in that electricity that your panels had been providing has to come from somewhere else.

Given that argument I might as well plug in my car at any old time because you say the displacement effect happens willy-nilly. Effectively you are saying that plugging in when I am producing doesn't make any difference to the above effect? A lot of companies are putting a fair bit of effort into shaping consumer demand to flatten peaks and match demand to production. Perhaps you should tell them that they are wasting their time. 

Yeah the 'marginal argument' is a bit silly and a FF argument to knock BEV's and heatpumps. Every new thing switched on uses FF's, therefore everything uses FF's as the day goes on, ignoring anything switched off, which by the same argument must reduce FF's.

Perhaps charging your BEV reduces demand on oil refineries, so their reduced demand reduces FF generation too, and then the added FF savings since about 40% of sea freight by weight is FF transport, so plugging in your BEV reduces that too. You can go in circles with these arguments for ever ....... which is kinda their point, to confuse and obfuscate, and suggest moving to cleaner, greener technologies isn't a good thing.

The single most important factor is that the UK grid is rolling out RE and displacing FF's faster than new leccy demand is added. In fact the UK has actually had a declining demand for leccy for over a decade, whilst RE has been displacing approx 3.5% of UK FF leccy generation each year.* But of course as we adopt the green policy and technologies of 'electrify everything', we can expect leccy demand to rise again, but the FF contribution to keep falling.

[Edit * - Bad English, not displacing 3.5% of FF's each year, deploying roughly an additional 3.5% of generation each year, which shifts demand away from FF's. I suppose, going back to when FF's represented ~70% of generation, then 3.5% additional supply from RE would be about 5% of FF's. Now that FF's are closer to 35%, a 3.5% additional supply would displace about 10% of FF's, but this is really just another number trick. M.]

orrery nailed it with 

What a strange view, you seem to admit the merit of my argument and then say, yebut arbut, when you turn it off ...

Your argument is pointless: we progressively add more renewables and therefore we get nearer to zero emissions, and we already know that the 100% coal fired EV starting point was better that ICE.

ICE fuel is a dirty filthy business (ref the video) and we're moving away from it. Every step we take along the path is a win, but still those following the Oil Company playbook (ex tobacco company playbook) still pop up trying to throw in obscure arguments to sow doubt, then others repeat it.

So, in the meantime, I use either pure 100% solar ('cos my charger can do that) or I charge overnight using leccy from my 100% renewables tariff (don't bother, we've done that one to death too).

JKenH

Martyn1981 said:

silverwhistle said:

JKenH said:

Quite simple really. Your panels are sending electricity to the grid for everyone to use to boil their kettles, charge their cars run their ASHPs, light their schools offices and factories. Once you plug your car in that electricity that your panels had been providing has to come from somewhere else.

Given that argument I might as well plug in my car at any old time because you say the displacement effect happens willy-nilly. Effectively you are saying that plugging in when I am producing doesn't make any difference to the above effect? A lot of companies are putting a fair bit of effort into shaping consumer demand to flatten peaks and match demand to production. Perhaps you should tell them that they are wasting their time. 

Yeah the 'marginal argument' is a bit silly and a FF argument to knock BEV's and heatpumps. Every new thing switched on uses FF's, therefore everything uses FF's as the day goes on, ignoring anything switched off, which by the same argument must reduce FF's.

Perhaps charging your BEV reduces demand on oil refineries, so their reduced demand reduces FF generation too, and then the added FF savings since about 40% of sea freight by weight is FF transport, so plugging in your BEV reduces that too. You can go in circles with these arguments for ever ....... which is kinda their point, to confuse and obfuscate, and suggest moving to cleaner, greener technologies isn't a good thing.

The single most important factor is that the UK grid is rolling out RE and displacing FF's faster than new leccy demand is added. In fact the UK has actually had a declining demand for leccy for over a decade, whilst RE has been displacing approx 3.5% of UK FF leccy generation each year.* But of course as we adopt the green policy and technologies of 'electrify everything', we can expect leccy demand to rise again, but the FF contribution to keep falling.

[Edit * - Bad English, not displacing 3.5% of FF's each year, deploying roughly an additional 3.5% of generation each year, which shifts demand away from FF's. I suppose, going back to when FF's represented ~70% of generation, then 3.5% additional supply from RE would be about 5% of FF's. Now that FF's are closer to 35%, a 3.5% additional supply would displace about 10% of FF's, but this is really just another number trick. M.]

orrery nailed it with 

What a strange view, you seem to admit the merit of my argument and then say, yebut arbut, when you turn it off ...

Your argument is pointless: we progressively add more renewables and therefore we get nearer to zero emissions, and we already know that the 100% coal fired EV starting point was better that ICE.

ICE fuel is a dirty filthy business (ref the video) and we're moving away from it. Every step we take along the path is a win, but still those following the Oil Company playbook (ex tobacco company playbook) still pop up trying to throw in obscure arguments to sow doubt, then others repeat it.

So, in the meantime, I use either pure 100% solar ('cos my charger can do that) or I charge overnight using leccy from my 100% renewables tariff (don't bother, we've done that one to death too).

Lots of obfuscation in that post bringing in sea freight, oil refineries and heat pumps plus requoting the post about oil and tobacco companies playbook to try and distract from the argument here which is simply whether charging your car on your own solar helps reduce CO2 emissions. 

Let’s try and make it really simple this time.

As a household you have PV generation of 4MWhpa

House use of 5MWh pa

EV use 2MWh pa.

Grid emissions average 200g/kWh (the exact figure doesn’t make any difference to the calculation but I have kept it a flat rate day and night just to keep it simple).

1. You only charge your during the day when the sun is shining from your own solar.

Grid emissions from house per year 5 Mwh x 200g/kWh = 1000kg CO2 

Grid emissions from charging car 2MWh x 0g/kWh= 0g

Less saving of 

Solar 2MWh Pv sent to grid offsets daytime grid generation of 2MWh x 200g/kWh = 400kg CO2

Net CO2 used 600kg CO2

2. you only charge overnight 

Grid emissions from house per year 5 Mwh x 200g/kWh = 1000kg CO2 

Grid emissions from charging car 2 MWh x 200g/kWh= 400kg CO2

Less saving of 

Solar 4MWh Pv sent to grid offsets daytime grid generation of 4 MWh x 200g/kWh = 800kg CO2

Net CO2 used 600kg CO2

We can see therefore it makes no difference to the overall CO2 consumed in generating electricity whether you charge it from your own solar or from the grid. It’s just cheaper to charge from your own solar.

Edit: as an individual household you use less CO2 but the grid uses more because you have sent less zero emissions generation back to the grid. 

JKenH

1961Nick said:

My observations of Gridwatch is that marginal generation is almost always the highest CO2 - coal, OCGT, CCGT It's therefore reasonable to conclude that since the overnight demand is half of the daytime peak, charging an EV overnight will account for less CO2 than charging it during the day.

The energy mix for March has been skewed by a lack of wind, a wholesale gas price over 250p/therm & a war. According to my app, the carbon impact of charging my car during March was more than double the lifetime average.

Let’s have a look at how charging from one’s own solar compares to charging overnight when the overnight emissions are lower? Same usage as in previous example (emissions quoted more or less what we were seeing on 29th March)

As a household You have PV generation of 4MWhpa

House use of 5MWh pa

EV use 2MWh pa.

Grid emissions average 290g/kWhDaytime emissions 300g/kmh 

Overnight emissions 275g/kWh 

1.You only charge your during the day when the sun is shining from your own solar.

Grid emissions from house per year 5 Mwh x 290g/kWh = 1450kg 

Grid emissions from charging car 2MWh x 0g/kWh= 0g

Less saving of 

Solar 2MWh Pv sent to grid 2 MWh offsets daytime generation of 2MWh x 300g/kWh = 600kg

Net CO2 use 850kg

2. you only charge overnight 

Grid emissions from house per year (as before) 5 Mwh x 290/kWh =  £1450

Grid emissions from charging car 2MWh x 275g/kWh=  550 kg

Less saving of 

Solar 4MWh PV sent to grid offsets 4 MWh x 300g/kWh daytime use = 1200kg

Net CO2 use 800kg

In this example, therefore, it uses 50kg less CO2 to charge from a cheap rate overnight than from one’s own solar. The situation would be reversed if daytime emissions were lower than overnight emissions but given @Nick1961’s observations above this is not generally the case.

Edit: figures corrected as I got them wrong first time round. Apologies 
Also added source of quoted emissions