Just Joined the Intelligent Octopus Tariff

[nowty]

As the TM3 is very low today, returned from my folks with only 7% battery left, I've managed to get 3.5 extra cheap hrs from the Octopus and they are all back to back from 8pm so will bank those, especially as SWMBO has a 50 degree washing load ready to go.

[John_S]

7 meters is a bit long, the requirement these days is 3m max length from cut-out to CU, but I wouldn't sweat it. Just keep an eye on your voltage "sag".

Ah, I was wanting to go from the Fuse to my 'power station' and back to the CU. 20 meters each way. I was intending to use 25mm cabling. Is this allowed in that circumstance? The higher power units would be connected direct to the 'power station'I don't want all the batteries in the house and the closest place I can have a shed is about 20m from where the power enters the house. I was working on about 3 V sag which would take me to 235V.

I will be getting an electrician for all this, but doing the general planning before hand.

'power station' = batteries + solar + generator.

You can achieve what you want, you just might have to do it slightly differently.

The tails from your meter will have to be 25mm² and will have to be terminated in a CU (Consumer Unit) within 3m. However you can go for a DB (Distribution Board) arrangement. A DB is a CU that feeds other CUs (the device is the same thing).

Here is an example: 25mm² tails from meter to DB. DB has 3 ways in use plus room for expansion: 50A MCB feeding 10mm² armoured to the "power station" CU. 50A MCB feeding 10mm² armoured to main house CU, 40A MCB feeding 6mm² armoured to EV charging point.

Obviously you have to get an electrician to do the calculations and specify the exact details based on the various criteria. Don't forget voltage "sag" works both ways! If your inverter is trying to push power into the grid, it'll have to increase the voltage, if the cable is too long and too thin the voltage will go too high and the inverter will turn off.

The 3m limit from the meter to the consumer unit / distribution board is per the wiring regulations and BS7671.

This you tube video from Efixx explains the requirements in more detail and that DNOs are allowed to stipulate a maximum of less than 3m eg 2m.

[nowty]

As the TM3 is very low today, returned from my folks with only 7% battery left, I've managed to get 3.5 extra cheap hrs from the Octopus and they are all back to back from 8pm so will bank those, especially as SWMBO has a 50 degree washing load ready to go.

The extra hours from the intelligent Octopus allowed me to smash my all time daily cheap rate import record yesterday, previously being 88kWh and yesterday being 113kWh. I know import of any energy is not great thing to brag about (especially at the moment with very low wind resource). But my empty EV had to be filled, SWMBO filled her EV from the previous night so that carried on into the early hours of yesterday, but the gas boiler is still off.

The peak rate import was 0.073 kWh or around 0.06% of the total import. And about one third of that could have been avoided if SWMBO had not turned the kettle on at the same time as the toaster whilst the heatpump and the heated kitchen heated floor was on. When I suggested the kettle could be postponed for a a few mins until the toaster was done there was a short burst of screaming so the kettle remained on.

[Stinsy]

I frequently mistake “cheap” electric for “free” electric. I keep having to remind myself that it isn’t a competition to use as much electric as possible during the cheap period!

[nowty]

I frequently mistake “cheap” electric for “free” electric. I keep having to remind myself that it isn’t a competition to use as much electric as possible during the cheap period!

If it was a competition, I'm sure I could have arranged for 18kW to be on for the whole 9.5 hr cheap slot and would be around a theoretical 170kWh.

The ultimate record for Nowty Towers will be the lowest ever kWh import in a single year. Its just to reduce the gas to near zero, reduce the carbon and to reduce cost to the lowest, it all has to be compressed into the cheap rate slot. So records do have to be broken to do that.

[Fintray]

When I suggested the kettle could be postponed for a a few mins until the toaster was done there was a short burst of screaming so the kettle remained on.

Women, they just don't get the importance of using as little as possible...

[nowty]

When I suggested the kettle could be postponed for a a few mins until the toaster was done there was a short burst of screaming so the kettle remained on.

Women, they just don't get the importance of using as little as possible...

Well the kettle did have to go on, it was just the timing. The problem I (and some of us have) is in Summer, there is generally no house heating required and tons of solar generation coming in, plus 6kW battery inverter at the ready so I say to SWMBO, don't worry, put whatever you want on, do your worst.

But in Winter, its totally reversed, next to no solar generation and house heat pump on, so its NO !, you cannot put everything on together. But you can after 23:30, eh, no its actually 23:34 because the clock on the meters wrong.

Then there are the shoulder months were it could be like Summer rules or it could be like Winter rules.

[Tinbum]

We have a 600w kettle, but to be honest we could use the 2800w without a problem.
I've been using about 35Kwh every night during the 4hr GO cheap slot and haven't used anything during peak hours. (I've also been using it to heat the top of the DHW cylinder).

[Andy]

Ah, I was wanting to go from the Fuse to my 'power station' and back to the CU. 20 meters each way. I was intending to use 25mm cabling. Is this allowed in that circumstance? The higher power units would be connected direct to the 'power station'I don't want all the batteries in the house and the closest place I can have a shed is about 20m from where the power enters the house. I was working on about 3 V sag which would take me to 235V.

I will be getting an electrician for all this, but doing the general planning before hand.

'power station' = batteries + solar + generator.

You can achieve what you want, you just might have to do it slightly differently.

The tails from your meter will have to be 25mm² and will have to be terminated in a CU (Consumer Unit) within 3m. However you can go for a DB (Distribution Board) arrangement. A DB is a CU that feeds other CUs (the device is the same thing).

Here is an example: 25mm² tails from meter to DB. DB has 3 ways in use plus room for expansion: 50A MCB feeding 10mm² armoured to the "power station" CU. 50A MCB feeding 10mm² armoured to main house CU, 40A MCB feeding 6mm² armoured to EV charging point.

Obviously you have to get an electrician to do the calculations and specify the exact details based on the various criteria. Don't forget voltage "sag" works both ways! If your inverter is trying to push power into the grid, it'll have to increase the voltage, if the cable is too long and too thin the voltage will go too high and the inverter will turn off.

The 3m limit from the meter to the consumer unit / distribution board is per the wiring regulations and BS7671.

This you tube video from Efixx explains the requirements in more detail and that DNOs are allowed to stipulate a maximum of less than 3m eg 2m.

Thanks to both of you for your answers. It all makes sense for me I was writing up something for a different thread but covid got in the way. I'll try and do that at some point as I've lost all the drawings I'd spent some time doing.

[nowty]

After my record import the other night, Alex@Octopus just sent me an email, looks like they want me to import even more cheap rate !
Hmmmm, they know my cars at its home location and its not plugged in, that's a bit too cheeky really.




Ok, it is now plugged in and an extra hour from 10pm till 11pm, I'll take that as SWMBO has some ironing to do.



OK Alex@Octopus, game on.