Smart meter randomisation of time change of cheap/expensive slot changes

[Andy]

I've been trying to read up on this subject and found this interesting document. https://committees.parliament.uk/writte ... 23426/pdf/
Now I need to work out the offset and apply it. The problem is that if Octopus are controlling my car start period they cannot take into account the random period as they don't have access. So then I can be paying 10 minutes on the expensive tariff. I might have to implement a hold back for 10 minutes on the charging to ensure it can never cost too much.

[Andy]

My liberty 110 has a 5th wire output that can be used to to power night storage heaters. If I had that connected I guess I could determine the change over time by when it becomes live.

[John_S]

Interesting read and I shall need to go through it in more detail.

First thoughts are that, given Joe Public has difficulty grasping the benefits of smart meters already, some of the unused features would give him/her nightmares. Even things as simple as block tariffs.

However, I am all for intelligent suppliers like Octopus having a range of tariffs which allow people like us to benefit from the extra features of smart meters.

I think that there is some confusion between randomised delay of tariffs changing and randomised delay of appliances starting. I have been on Octopus Go/IOG for over three years and have absolutely no suspicion that Octopus has ever delayed the start of the cheap slots beyond 0030 or 2330. Given that the Octopus bill only gives the amount of electricity used at the two rates each month and not the meter increment during the month, I always download the half hourly data and get Excel to tell me the cheap rate and high rate totals - which always agree to the bill, although I have to manually adjust for the extra IOG slots.

I have no issue with IOG randomly delaying starting the EV charger and notice that it regularly does this.

If I remember correctly, a long time ago, night storage heaters were on a seperate circuit with a seperate meter operating on a time clock. These time clocks could be randomised to spread the start, and end, of the low rate period. In due course these separate circuits were done away and dual rate meters were used, which gave the added benefit that other appliances benefitted from the cheap rate.

[nowty]

The only thing that is currently being implemented is the ability to remotely control newer installed EV chargers and give them a small random start delay.
https://www.gov.uk/guidance/regulations ... rge-points

There is no randomising of smart meter cheap / expensive slots.

The Octopus IOG tariff may control your charge by randomly stopping and re-starting the charge but all the half hour slots in the IOG schedule are still at cheap rate.

[Andy]

The only thing that is currently being implemented is the ability to remotely control newer installed EV chargers and give them a small random start delay.
https://www.gov.uk/guidance/regulations ... rge-points

There is no randomising of smart meter cheap / expensive slots.

The Octopus IOG tariff may control your charge by randomly stopping and re-starting the charge but all the half hour slots in the IOG schedule are still at cheap rate.

That ties in with my usage being quite accurate with my start stop times. So did they scrap that idea in the end?

[Sim_C]

I have been on an ECO7 tariff for some time, initially with a non-smart meter and now with a SMETS2 meter.

The non-smart meter had 2 registers, 1 for the low and 1 for the normal consumption, and the meter toggled between them at 0030 and 0730 GMT based on the date/time in the meter itself. The date/time in the meter was not synchronised with any refererence, so as the clock drifted from actual then so did the low/normal tariff timings. On meter reading day, I just provided the 2 consumption values to the supplier for billing.

On switching to the SMETS2 meter with Octopus, the commissioning process included configuration data being loaded in to the meter to utilise 2 registers and the 2 tariff rates for the IHD to be able to read and calculate costs per period (daily/weekly etc). The config must have included the tariff switching times, as I found by experimentation that the same 0030 to 0730 GMT applied but this time accurately as the meter time is kept synchronised. On meter reading day, I still provide the 2 consumption values to the supplier for billing after pressing buttons on the meter to change the displayed values and now a seperate export value as well.

With being on ECO7 flexible that follows the price cap now every 3 months, the SMETS2 meter config was periodically updated with the new rates but not necessarily on the 1st of the month of the price change. Following one of these price changes around the 20th of the month I discovered some of my overnight EV charging had started to be registered on the expensive day rate. Octopus could/would not advise me of the actual tariff time periods so I had to find by experimentation.

On the SMETS2 meter itself the currently active tariff consumption value appears to be displayed (when no buttons are pressed), so if watching when the tariff is expected to change will confirm the actual timing. Mine is now 0100 to 0800 GMT, so I have the EV charge sessions set to 0115 to 0745 GMT and with a GivEnergy battery system am getting day consumption of around 2 kWh per month (unless there is an exceptional event such as GE battery calibration). The night consumption has been over 600 kWh/month this Winter depending on EV charging requirements.

What I cannot determine is whether Octopus have downloaded a config with the 0100 to 0800 times, or it is 0030 to 0730 with a 30 minute random delay period.

As far as I know the Intelligent Octopus tariffs do not utilse separate registers in the SMETS meter, just 1 register is recorded every 30 minutes and the varying costs applied on their billing system computer, hence the timings are aligned with the 30 minute time slots.