@
geoffers
Unless I'm missing something here, if you submitted a meter reading they would know to within 30 minutes when that reading was taken and could just bill up to that point couldn't they? The supplier is billing to ToU that they themselves have specified so they would know the meter readings for every 30 minute period.
Equally, they could just give you a 'Bill now' button on the website that generates a bill up to the latest 30 minute period prior to the request.
As far as I can see Next Drive is essentially E7 under a different name but with cheaper prices 🙄, the hours are fixed. Presumably the entire household is on the EV tariff during the 7 hour period, so it's no different to E7 as far as I can see.
Surely with E7 they must have 2 meter registers/readings: one for the off-peak times and one for the peak times.
So they know the 2 separate values for total-kWh used for off-peak rate and total-kWh used for peak rate
With ToU they don't use the (single) total-kWh reading to calculate the bill: how can they possibly know how much of that reading was the cheap rate and how much was the peak rate.
The meter doesn't store a meter-reading "total" taken every ½hr.... It stores the actual incremental quantity of kWh used for that ½hr.
The way they then calculate the bills for the Next Drive ToU is to total the 14 ½ hourly incremental readings for the seven hours of off-peak leccy and multiply this by the cheaper tariff.
Then do the same for the 34 ½ hourly incremental readings for the seventeen hours of peak rate, multiplying this total by the daytime tariff.
The bill then shows a total kWh used for the bill period (the 2 totals above added together). The total cost calculated above for the night and day rates is then used to display an "averaged" tariff for the period
For instance my last bill was
6.381p/kWh 110.3 kWh =£7.04
23.202p/kWh 114.6 kWh =£26.58
So that equated to an "average" tariff of 14.95p for that month's 224.8kWh of electricity used, shown on the bill as
224.8kWh @ 14.95p/kWh = £33.62
The average value is different every month, depending on the proportion of nighttime/daytime electricity used