[EV7]

Re: 'you can view your meter readings at any time'.
Unfortunately the update this morning didnt seem to sort it out - the leccy meter readings are still invisible 😓.
See the purple banner attached where the readings should be.
Thanks for the welcome 😉

[geoffers]

@EV7

Originally Posted by EV7

..The EV smart chargers have to be randomised so they don’t all switch on at the same time and can start anywhere between midnight and 00:30 and finish seven hours later....Similarly Eco7 meters all seem to be set to sometime after midnight so they don’t all start at the same time and give you 7 hours of low rate which you can use to charge the car....People may be charged half hour at max rate after 7 am and so not quite achieve what they were hoping

OK – so here’s my theory (ahem…but I don’t know if this is how it’s actually implemented)

1. With legacy E7 systems Circuit-A is connected all the usual household appliances, and Circuit-B ran night-storage heaters etc
2. Back in the day Circuit-B was energised with a randomised timer sometime between 00:00 & 00:30 so that there wasn’t a power surge with all E7 timers starting at the same instant
3. A daily total reading was taken for both circuits so each day’s cost could be calculated based on the normal and off-peak rates

Now there’s hopefully a combination of modern smart metering plus legacy E7 in the dual rate smart meters

1. So if Circuit-A is now monitored on a ToU basis (using the ½ hourly usage readings), the electricity can be billed with the cheap rate applied between 00:00 and 07:00 and the daytime rate for the remainder of the day. A daily reading is no longer required for this circuit.
2. Circuit-B can still be costed on a “daily reading” basis, with the off-peak usage and costing per day being the difference between the current and previous readings.
3. So this would give the best of both worlds, but you need to ensure that your EV charger is wired into Circuit-A

The concern about power surges with all EVs starting to be charged at midnight seems to have been ignored in this brave new world

[EV7]

@geoffers - naturally the EV would be connected to the low rate circuit so it powers up the charger at the right time and you know exactly how much low rate youve used.
With the system youve mentioned there's no guarantee the charge start finish times are the same as the billing times. It seems none of them will be exactly 00:00 and 07:00.

Apparently both low and normal meters are read every half hour to show ToU - the normal rate meter reading increments during the day, and the low rate meter reading increments over night.
All those reads could be displayed on the website if needed / selected and of course they form the basis for the app which uses the meter readings to calculate kWh,
In practice the minimum you need displayed are say when the monthly billing period ends/begins or if say you submit a manual reading.

The concern about all EVs starting charging at the same time has been taken care of in the regulations where they say it should be randomised - pretty much the same as the ECO7 meters.

Anyway for now we just need the readings to be unhidden from behind that purple banner 🙂

[geoffers]

Originally Posted by EV7

@geoffers With the system you've mentioned there's no guarantee the charge start finish times are the same as the billing times. It seems none of them will be exactly 00:00 and 07:00.

Aaah OK - didn't realise that the EV chargers have randomised start times.

I have a single-rate meter and charge my EV from a standard 13amp plug (@2kW = 8amps) so can happily use the full 7 hours of cheap rate leccy between midnight and 7am.

I guess anyone else with an EV charger can only be 100% sure of using 6½ hours worth of cheap leccy, as they may run into the daytime rate if their charger is set to charge for 7 hrs and starts sometime after midnight

However most other suppliers only seem to offer 5hrs cheap rate, so EOn is still pretty good if you can get 6½ out of the overall 7 hours charging