EV Discussion thread

Alnat1

If it was to do with the general cost of living, then the % wouldn't have changed and all "inquiries" would be down.

It seems to me it's all to do with the price of electricity. Can't read the full article, maybe they did go on to say that.

1961Nick

Grumpy_chap said:

JKenH said:

Drop in demand for electric cars as cost of living crisis bites

Auto Trader said EVs accounted for fewer than a fifth (19%) of new car inquiries sent to retailers through its online marketplace last month.

That is down from 27% in June.

https://www.standard.co.uk/business/business-news/drop-in-demand-for-electric-cars-as-cost-of-living-crisis-bites-b1046733.html

That may well be linked to the general media stuff about EV's now being expensive to run because electric prices have risen.
It is true, but petrol prices have also risen, so the comparison needs to be on current-day to current-day prices, not (as some media seem to compare) today's price for electricity and a previous price for petrol.
It still seems favourable as far as I can tell to go for an EV if only considering running (fuel / energy) costs.
Some can also benefit from reduced cost electricity (solar or free destination / workplace charging).

Costs to acquire a new EV remain high but I am sure will correct themselves. 

All the comparisons seem to compare the cost of public charging an EV with the cost of running an ICE. There's often a footnote to say that you can reduce the cost of charging by home charging but without mentioning that it's 80% cheaper to charge at home overnight.

EricMears

All the comparisons seem to compare the cost of public charging an EV with the cost of running an ICE. There's often a footnote to say that you can reduce the cost of charging by home charging but without mentioning that's 80% cheaper.

Indeed,  they don't even take the trouble to work out petrol costs at MSE prices rather than cheapest or even average cost of fuel.

Grumpy_chap

1961Nick said:

 it's 80% cheaper to charge at home overnight.

Only for some - these tariffs are not available to all.
It is also not guaranteed that the lower overnight electricity rate won't be neutralised by the higher day rate.

silvercar

Grumpy_chap said:

1961Nick said:

 it's 80% cheaper to charge at home overnight.

Only for some - these tariffs are not available to all.
It is also not guaranteed that the lower overnight electricity rate won't be neutralised by the higher day rate.

this^^. I could I guess move to Octopus or BG EV/ night rates, but the day time rate would be at least 15-20% more, so it doesn't make sense to do so compared to charging rates I can find locally.

Martyn1981

Grumpy_chap said:

1961Nick said:

 it's 80% cheaper to charge at home overnight.

Only for some - these tariffs are not available to all.
It is also not guaranteed that the lower overnight electricity rate won't be neutralised by the higher day rate.

Hopefully overnight charging will be seen as a benefit to the grid, as it helps to flatten out demand. Also V2G (or just V2L/H) may help to reduce peak demand, so there may be benefits to all involved, in encouraging night charging. But, this is of course speculative, and I think, will depend eventually on the amount of night time demand from heat pumps.

Only a US study, but it seems that BEV's can help to reduce utility costs.

Do Electric Vehicles Actually Cut Utility Costs?

Does increasing the number of electric vehicles (EVs) on the grid actually result in lower utility costs for all customers?

That is just what a recently revised study found. The study shows that EV users are not receiving subsidies from other customers and that, in fact, they are driving prices down. Overall, EV consumers have provided more than $1.7 billion in net revenue to utility customers between 2012 and 2021 in three US-based utility service areas that have the most EVs.

1961Nick

Grumpy_chap said:

1961Nick said:

 it's 80% cheaper to charge at home overnight.

Only for some - these tariffs are not available to all.
It is also not guaranteed that the lower overnight electricity rate won't be neutralised by the higher day rate.

Intelligent Octopus is 6p/kWh more expensive than the price cap - 40p v. 34p. With some load shifting to the 6 hour off peak period, the extra cost of daytime electricity can easily be recovered.

In addition, once the car is plugged in a charging schedule is created that often includes extra off peak periods. A friend of mine plugged his Tesla in the other day & was given 15h 35m of off peak electricity over a 24 hour period.

Grumpy_chap

Martyn1981 said:

Hopefully overnight charging will be seen as a benefit to the grid, as it helps to flatten out demand. Also V2G (or just V2L/H) may help to reduce peak demand, so there may be benefits to all involved, in encouraging night charging. But, this is of course speculative, and I think, will depend eventually on the amount of night time demand from heat pumps.

When the subject to load-shifting was discussed upthread, someone else (or it may even have been you) mentioned using ASHP to load-shift to night.
I don't understand how that works. 
As I understand it, ASHP provides space heating when the unit is operating.  So, heating at night means I am too hot in bed and cannot sleep.  It does not allow me to store the heat for the morning.
I also understand that ASHP efficiency is worse when air temperature is lower, like at night.

Martyn1981

Grumpy_chap said:

Martyn1981 said:

Hopefully overnight charging will be seen as a benefit to the grid, as it helps to flatten out demand. Also V2G (or just V2L/H) may help to reduce peak demand, so there may be benefits to all involved, in encouraging night charging. But, this is of course speculative, and I think, will depend eventually on the amount of night time demand from heat pumps.

When the subject to load-shifting was discussed upthread, someone else (or it may even have been you) mentioned using ASHP to load-shift to night.
I don't understand how that works. 
As I understand it, ASHP provides space heating when the unit is operating.  So, heating at night means I am too hot in bed and cannot sleep.  It does not allow me to store the heat for the morning.
I also understand that ASHP efficiency is worse when air temperature is lower, like at night.

Depends on the situation, season, and prices. In the shoulder months, there's not much point, just wait for the PV gen to climb, then heat that way (via a HP).

But if you have leccy at half the price at night, then you can put some heat into the house (bit like a battery), to reduce GCH use the next day, or if you have HP heating already, just to save money.

Yes the air temp will be lower at night, so the COP will be less, but if the price difference is high enough, then using the night rate can be advantageous.

Not sure about your 'too hot to sleep' comment, I think you may be taking the issue a tad too far, you can run the HP at a lower target temp at night.

Taking the issue to the extreme, for a really well insulated property, using a wet system HP, and/or underfloor heating, then you may have it running 24/7 to maintain temps (lower of course in the bedrooms). So a cheap rate boost, with lower daytime rate usage would make sense.

Another example may be a wet system, running off a thermal store, heated electrically during cheap rate, or better still, a HP to apply a COP.

Even if it's just the hot water tank (ordinary or HPHW), it still works as a battery shifting cheap rate leccy to daytime use, just like the original idea for nuclear with Heat Electric & E7.

Probably loads more examples, but hopefully I've painted a picture of some of the possibilities.


Edit - Just to say, I am looking at this from a UK perspective, as other countries will have better PV resources. For the UK we can expect to get the majority of our winter gen from wind, so making use of any nightime excess, over and above 'normal' demand, will make sense.

Grumpy_chap

Martyn1981 said:

Not sure about your 'too hot to sleep' comment, I think you may be taking the issue a tad too far, you can run the HP at a lower target temp at night.

I am not sure how I can put heat in the house at night to use as a battery.

In our house, we will have the temperature at 19 - 20 degC in the evening.
The gas CH switches off about an hour before bed.
The coldest the temperature drops to overnight is around 13 - 14 degC (even the current cold snap).  We have a min-max thermometer.
The heating will switch back on about an hour before we get up.  This is probably still after cheap rate electricity would have finished.  We get to about 18 degC in the morning heating cycle.
If we are out, the heating is off during the day.  If I am home alone, the heating is off during the day and I use a local electric heater (250 W) in the study.
The heating then comes back on late afternoon, so we have 19 degC again for the evening.

Using an ASHP at night would only be heating the house when I am sleeping.  Not convinced I'd get to save any energy / money.