Road Tax on EV's

Ectophile

The electricity supply in the UK is roughly one third gas, one third nuclear and one third wind.  But that varies from day to day, and between day and night.  So it's about two thirds non-fossil-fuels.

Jenni_D

According to Wiki there is currently 4GW of coal-fired generating capacity in England, but that capacity will soon be removed. (There used to be lots of coal-fired power stations in the UK, but most have been shut down or converted).

Excel file 5.1 here may be of interest to some.

Herzlos

https://grid.iamkate.com/ gives you live figures on power supply. We're currently generating 1.1GW (3%) from coal but 3 times as much from wind.

Petriix

The average grid CO2 per kWh last year was roughly 200g so around 60g per mile for your average EV. Around 1/3 of my charging comes from home solar so I'm running at 40g per mile or 25g per km. That compares to the ~ 150g per km real world average of my previous efficient diesel (119g per km official figures). So usually 1/4 of the emissions but 1/6 in my case. 

That's not the whole story because I mostly charge overnight if using the grid. I could probably track my charging vs historical grid data and I suspect it would be lower. 

Then of course there's no tailpipe emissions and vastly less brake dust. 

The carbon footprint of an EV battery is a one off. They will be re used and recycled regardless of what happens to the car they're attached to, unlike the fossil fuels which are burnt away.

In any case, it's costing me an average of 1.1p per mile to charge. The value has apparently gone up since I bought it new so it's just the ~ £400 interest and £33 first service. Under £600 in total for 13k miles. In addition, EV ownership gives me access to much cheaper electricity - I pay just 5p per kWh for 80% of my usage and an average of under 9p in total. 

DrEskimo

Petriix said:

The average grid CO2 per kWh last year was roughly 200g so around 60g per mile for your average EV. Around 1/3 of my charging comes from home solar so I'm running at 40g per mile or 25g per km. That compares to the ~ 150g per km real world average of my previous efficient diesel (119g per km official figures). So usually 1/4 of the emissions but 1/6 in my case. 

That's not the whole story because I mostly charge overnight if using the grid. I could probably track my charging vs historical grid data and I suspect it would be lower. 

Don't forget the additional carbon footprint to mine, extract, refine, and transport the fuel to a petrol station. Easily adds another 20%+ to the real world tailpipe emissions, making the difference even larger.

People like to talk about the generation of the electricity for an EV, but seem to conveniently forget the generation of the fuel...

MouldyOldDough

Does an EV Lithium battery deteriorate with age - as well as mileage ?

ie) Would a low mileage user (say 5,000 miles per year) get twice as long out  of the battery, before it started to lose its ability to hold a decent charge - than someone who drove 10k pa ?

[Deleted User]

MouldyOldDough said:

Does an EV Lithium battery deteriorate with age - as well as mileage ?

ie) Would a low mileage user (say 5,000 miles per year) get twice as long out  of the battery, before it started to lose its ability to hold a decent charge - than someone who drove 10k pa ?

No. Electric cars need to be used regularly just like ice cars. Taxi companies are reporting that their fleets of Leafs with circa 150k miles have minimal battery degradation and that’s with constant use of rapid charging. 

So it would seem the benefit from heavy use. 

DrEskimo

MouldyOldDough said:

Does an EV Lithium battery deteriorate with age - as well as mileage ?

ie) Would a low mileage user (say 5,000 miles per year) get twice as long out  of the battery, before it started to lose its ability to hold a decent charge - than someone who drove 10k pa ?

Data I've seen from other Zoe's indicates it's mileage, rather than age that drive the battery state of health (SOH).

For example mine is over 5yrs old now, but only done 17k miles. I'm sitting at 97% SoH. Other uses who hit that 17k mile mark after just 1 or 2 yrs are seeing the same 97% SoH.

But it helps that most older gen Zoe's could only charge up to 22kW AC (there are some that charge up to 43kW AC), as rapid charging beyond 50kW will affect the rate of deterioration. 

MouldyOldDough

Deleted_User said:

MouldyOldDough said:

Does an EV Lithium battery deteriorate with age - as well as mileage ?

ie) Would a low mileage user (say 5,000 miles per year) get twice as long out  of the battery, before it started to lose its ability to hold a decent charge - than someone who drove 10k pa ?

No. Electric cars need to be used regularly just like ice cars. Taxi companies are reporting that their fleets of Leafs with circa 150k miles have minimal battery degradation and that’s with constant use of rapid charging. 

So it would seem the benefit from heavy use. 

Right - so EVs do not suit light users ?

Not only cost per mile but also replacement battery-wise ?

Think I'll stick with my low emission IC car

Only done 10k miles in 5 years

Averages 55mpg and costs £30 pa road tax, and, since it already exists - wont use any build resources

Herzlos

EV's are great for light use - you can charge at home as you need, and there's less stuff to go wrong with low usage - liquids and lubricants to drain, fuel to go off, engines to get up to temperature, etc.

The higher (current) purchase prices may mean that they take longer to reach a break even point, but the lower usage means the shorter range in older EV's shouldn't be a problem.

2000 miles / year is 38 miles / week, so pretty much any EV on the market will be able to do that with a weekly recharge. The only difficulty would come in if somehow you only covered 2000 miles a year but that was from a single trip to Europe and back, in which case I'd be rethinking car ownership entirely.