EV Discussion thread

Martyn1981

Grumpy_chap said:

ToU tariff is something we are considering.  I'd need a smart meter.

I note that whenever people post about ToU tariffs the emphasis is always on the cheap rate and so very rarely mention that the day rate is at a premium higher than standard.  There was a long thread some while back about time-shifting and I think I concluded the only thing I could sensibly time-shift was the dishwasher which is a pretty low demand in any case.

The EV is a big load, though.  Our daily electricity is about 10kWh so the 44+kWh for charging the car is equivalent to 5-days power consumption.

Solar PV is probably more likely to be beneficial than ToU.

We were the same, I kept doing the maths, and E7 just didn't work .... until we got the BEV. With a BEV(s) you can pretty much guarantee moving a huge demand to the cheap rate, whereas it's not so easy with other items.

PV does help, since the higher day rate will be used less if you have PV, but our demand was too low to make it work. I think when we switched to E7 the tariffs were roughly 15p/kWh, changing to 10p E7 and 17p day time (the other 17hrs). Cheaper night rates were available, but the deal included a 'free' smart charger.

Take a look at the tariffs, and how much mileage (kWh's) you expect to charge from home. Then simply do the maths, and see how it looks. Bear in mind, that even with 4hrs at 7kW, or worst case 4-7hrs at 2kW, you can still charge the car almost entirely on cheap rate, if you build up the charge over a few days, and (on average) your mileage is covered.


Just to say, we've noticed that our Tesla granny charger seems to pull about 2 to 2.2kW, whilst the IONIQ charger is about 2.4kW. Plus the Tesla can be dialed between 5-10A* with the app on granny charge, so works better with the PV, as our generation (in power) isn't huge, especially when there are clouds.

*Upto 32A with the smart charger.

michaels

Our leaf granny charger used to read about 2.2kw on  a plug socket meter. Took the Leaf to London then Sussex yesterday, needed full power AC which uses more battery but found a plug socket to granny charge at the event in Sussex so were able to avoid a stop on the way home.  However even driving at 60 on a warm days I think the max range we could get out of our 40 is about 135 miles which is a bit disappointing.

silvercar

If you want a ToU tariff without a premium day rate, look at OVO charge anytime as it operates as an add on to the main tariff. You can only charge the car at the discounted rate of 10p/KWH. We have this because we also can’t shift much use to night time and we use this as a back up to our still free (car parking fee only) charging that we use most of the time.

silverwhistle

Exiled_Tyke said:

Are you eligible and is it practicable for you to get a TOU tariff?  With a smart meter and a Tesla you can et Intelligent Octopus which will give you 6 hours a night at 7.5p per kWh.    If you also scedule other appliances for the night slot (dishwasher, washing machine) then you can even bring down the 'pre-EV' costs of your electricity.    I also have a Zappi which monitors my solar PV production and during the day only sends excess power to the car bringing the cost down even more.

Handily the IO bill gives your overall average which helps comparisons. Before the July reduction I was averaging just over 17p on low mileage but with PV. I even get some charging via solar and granny when I can be bothered and the clouds co-operate, so overall my fuel costs are not something I worry about. I can't really justify E_T's solution of a battery and Zappi to enable fuller use of my solar.

I may go back to Agile having flexibility to benefit from it: I don't think there will be a shortage of LNG this winter, more wind is coming on-stream both here and in the rest of Europe, French nuclear in a better situation. We just need a good wet winter for the hydro (and the skiing!)..

Exiled_Tyke

" I can't really justify E_T's solution of a battery and Zappi to enable fuller use of my solar."

Neither can I !    But I have a set of circumstances which won't be common to many so perhaps I shouldn't have mentioned them!

1. I got a great price on the battery which meant that it would just about pay for itself so I took the plunge.  Since electricity prices soared it's turned out to be a better investment than I antcipated.

2. There were no decent export tariffs available at the time.

3. Similarly the Zappi isn't the best investment but it wasn't a lot more (from the quotes I got) than something more standard and may in time just about cover the difference in cost.  In addition  it helpfully monitors my PV, grid and house better than the other apps I have as it works live and not on periodic updates.  

Petriix

Octopus Intelligent covers 25% of the day by default so it already shifts quarter of your base load into the off-peak window. The tumble dryer is a big load in the winter so shifting that overnight also really helps. The washing machine and dishwasher add up over the whole year. We're over 70% off-peak on just the 4 hours of Go. It's madness to avoid a TOU tariff because of the perception of paying slightly more for some peak usage when the savings are so huge overall. 

Grumpy_chap

Petriix said:

Octopus Intelligent covers 25% of the day by default 

No, it does not.
It covers 11:30 pm to 5:30 am.
They are 100% night hours.

There is a big difference between "25% of every 24-hours" and "25% of the day".

Shifting tumble dryer to night to avoid peak tariffs is daft.  I very rarely use the tumble dryer - perhaps half a dozen times in the year.

If I shifted the washing machine to finish at 05:30, I'd have stuff sitting and getting creased for an hour or so before I can take it out.  Then I'd be transferring to tumble dryer as an alternative to air drying, so increasing energy use overall.  No time in the morning rush to go hanging washing.  I also won't know when setting a load before bed whether it will be fine or rainy when I wake.

As I mentioned a few posts upthread, that leaves only the dishwasher to time-shift.  That really is a small consumer.

Petriix said:

It's madness to avoid a TOU tariff because of the perception of paying slightly more for some peak usage 

It's equally madness to promote ToU tariffs as a solution but ignoring the uplift in standard rate.

Exiled_Tyke

How much would the uplift be in standard rates for you?  I can't see a difference from the Octopus tariffs I've looked at.

On balance I'm with Petriix here.  There are very signficant savings to be made but timeshifting does take a bit of effort. e.g. when I need to put the washing machine on at night I do it when I'm going to be at home the next day (weekend or working at home day) and then there's no really issue in getting it dry. 

Petriix

What uplift? How much extra do you imagine it costs?
On my last bill my average unit rate was 22p per kWh, despite the peak rate being 41p. That's the highest I've ever paid. My peak rate is now 31p. My average unit rate this month will be below 15p again. 

Exiled_Tyke

I  was commenting on the standard day rate. Currently (unless I've got it wrong) both the  standard day rate and the standard charge are the same on Go as the flexible rate so there's no reason not to go on a flexible tariff. (And it's the same for the other tariffs but some have extra charges for the evening peak).

That said my time shfiting has given me  a weighted average 9.5p in June and it only peaked at 14.5p in January.  It's been well worth the effort for me to make the most of TOU.