Dual Tarriff Meter for home

[skilly1]

I charge my i3 almost every evening from flat and am looking to get a peak / off peak electricity account. I have heard your peak charges are much higher than usual during the day, but the night tariff is heavily discounted.

Has anyone done this?

Also how do I work out if it will be of benefit to me, I have no idea how much daytime electricity I use or how much (real world not BMW stats!) electricity I use to charge the car?

[mids]

Yes, I've done this. I'm paying 15.8p/kWh day and 4.34p/kWh night and that's with British Gas, fixed until May 2015.

The night rate only comes on very late for about 7 hours. Exact timing depends on your distributor, mine (Western Power) start it at 11:30pm. Because of this you could simplify your comparison calcs by assuming that its only your i3 charging that is being carried out on the night tariff and that all of your other consumption is on the day tariff (assuming of course that you aren't running anything that consumes a lot of juice overnight (my house idles at about 0.2kw/h overnight so it's pretty insignificant)).

So, look at your leccy bill before you bought your i3 to find your kwh consumption, then measure your i3 charging consumption and you can work out if this split tariff is worthwhile.

To work out how much you're consuming when charging your i3 then it's possible to buy a meter off ebay for about £30 to log this. Alternatively, if you opt for the BMW wallbox you get one of these included in the installation (or at least I did).

http://farm4.staticflickr.com/3802/12598257674_d6b...

Edited by mids on Wednesday 2nd April 19:33

[Carparticus]

Mids - who is your provider? (rather than the distributor)

4.3p night rate is nearly 50% cheaper than mine (E-on) and I use a lot of leccy at night (for EV topping up at 32amps, immersion water heating, and loads of stuff on timers like washing machine / tumble drier / dishwasher, some back ground heating etc etc).

Theoretically is it "legal" to store cheap econ7 electricity and then use it during the day ?!? My annual e-on bill runs to around £3k and rising, so the expense of this is not as daft as it sounds...

Edited by Carparticus on Thursday 3rd April 00:36

[mids]

Hi Carparticus : That's with British Gas. I rang them just before I got my i3 to see if there was a better tariff that would suit charging an EV overnight and that's what they suggested. I was a bit surprised by how cheap the night rate was and it's a bonus to have it fixed until May 2015. Imagine being able to fix your petrol/diesel cost like that.

I've heard that BG (Centrica) are running a trial scheme for smart-meter customers which provides free electricity on Saturdays (to help smooth out the peak demands during the week). That's something else that might be pretty good for an EV owner.

[TimJMS]

Carparticus said:

...Theoretically is it "legal" to store cheap econ7 electricity and then use it during the day ?!? My annual e-on bill runs to around £3k and rising, so the expense of this is not as daft as it sounds...

It must be legal. The biggest battery in the UK is charged using Economy 7 http://www.electricmountain.co.uk/en-GB/Dinorwig

[Carparticus]

mids said:

Hi Carparticus : That's with British Gas. I rang them just before I got my i3 to see if there was a better tariff that would suit charging an EV overnight and that's what they suggested. I was a bit surprised by how cheap the night rate was and it's a bonus to have it fixed until May 2015. Imagine being able to fix your petrol/diesel cost like that.

I've heard that BG (Centrica) are running a trial scheme for smart-meter customers which provides free electricity on Saturdays (to help smooth out the peak demands during the week). That's something else that might be pretty good for an EV owner.

Thanks for that - I'll go check it out next, as I'm a tad unhappy with E-on ..

[Carparticus]

TimJMS said:

Carparticus said:

...Theoretically is it "legal" to store cheap econ7 electricity and then use it during the day ?!? My annual e-on bill runs to around £3k and rising, so the expense of this is not as daft as it sounds...

It must be legal. The biggest battery in the UK is charged using Economy 7 http://www.electricmountain.co.uk/en-GB/Dinorwig

Ah yes, that would be Electric Mountain! I remember as a kid in the 70s seeing programs about how a mountain was "hollowed out" and used as a giant hydro store. Cost a mere £400m back then, yet we could now do with dozens more as energy storage is the new Holy Grail.

The engineering statistics are impressive. 0 to 1,800 Megawatts in 15 seconds and it can run for 6 hours when 'full'.

Wind the clock forward a few decades and I end up parking an EV right out side the entrance area, and get to see the inside of the mountain first hand. The tour around the inside is fascinating although they don't allow you enough time to take it all in. Ironically they don't have EV charging on site !!

Edited by Carparticus on Thursday 3rd April 19:10

[skilly1]

mids said:

Yes, I've done this. I'm paying 15.8p/kWh day and 4.34p/kWh night and that's with British Gas, fixed until May 2015.

The night rate only comes on very late for about 7 hours. Exact timing depends on your distributor, mine (Western Power) start it at 11:30pm. Because of this you could simplify your comparison calcs by assuming that its only your i3 charging that is being carried out on the night tariff and that all of your other consumption is on the day tariff (assuming of course that you aren't running anything that consumes a lot of juice overnight (my house idles at about 0.2kw/h overnight so it's pretty insignificant)).

So, look at your leccy bill before you bought your i3 to find your kwh consumption, then measure your i3 charging consumption and you can work out if this split tariff is worthwhile.

To work out how much you're consuming when charging your i3 then it's possible to buy a meter off ebay for about £30 to log this. Alternatively, if you opt for the BMW wallbox you get one of these included in the installation (or at least I did).

http://farm4.staticflickr.com/3802/12598257674_d6b...

Edited by mids on Wednesday 2nd April 19:33

Thanks for the reply, I have spoken to BG and they have quoted off peak (8pm - 4pm) 11.95p an peak (4pm - 8pm)18.42. This is way more expensive than yours, don't suppose you can see what you plan is called on the bill?

[mids]

skilly1 said:

don't suppose you can see what you plan is called on the bill?

That is quite a bit more but the hours suggest it's a different tariff ?

I've just sent you a PM with a screeny showing my tariff details from when logged in to my account on the BG website.

[skilly1]

Great - thanks for that.

[skilly1]

Great - thanks for that.

[LordFlathead]

mids said:

That is quite a bit more but the hours suggest it's a different tariff ?

I've just sent you a PM with a screeny showing my tariff details from when logged in to my account on the BG website.

Mi mids, I've just pinged you an email. Is there any chance you could do the same for me? I've got a 32amp charging point being fitted by BG on Wednesday. My tariff options look rather scary at 18p/kwh