@transparent Thanks for the input.  I'm an engineer myself so I'm more than happy to tweak and improve my setup.

I can't imagine that anyone other than a marketing bod would come up with Cosy as a name.

Agree with battery storage being the better storage option but not one I have at the moment.

Doubt I'd look any further than Agile when I move as I can see some reasonable savings against my standard non-smart meter tariff just by shifting usage.

@dpc I encourage looking at getting on the Tracker tariff. Uses a daily rate day & night. (not Agile which uses half hourly rates). Ave in 2023 just over 23p. Today 18.6p inc vat.

Currently a waiting list to get on it but likely to be 6 months - or less. And no commitment so easy to come off it if prices spike. But last 3 months have always been sub capped rates

Posted by: @dpc

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Agree with battery storage being the better storage option but not one I have at the moment.

I placed an intro to Battery Storage on the Hello topic recently.
There some links at the bottom of my post.

Are you the type of engineer who has a workshop of tools, or a screen full of code?

@transparent pls confirm link to that info? 

https://renewableheatinghub.co.uk/forums/postid/16199

@transparent Mechanical Engineer with a smattering of electronics.  Definitely not a coder.

Sorry @tim441 that the link didn't work for you.
I'd used the 'short-form' version which should be ok whilst jumping within this forum.
... but I've now re-edited the post and used the long-form (universal) variant.
Try again.

Posted by: @dpc

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Mechanical Engineer with a smattering of electronics.

That's a good-enough platform on which to build a magnificent storage battery.

I got my first salaried job (in underwater robotics) because I knew which was the hot end of the soldering iron. 😉 

There are two major drawbacks in this country's quest to go Net Zero:

a) the general public know far too little about energy issues. Choosing a tariff is about the limit of their understanding.

b) we haven't got nearly enough people in their teens and twentys who are 'hands on'.

50-years ago there was a healthy pool of teenagers who'd spent their weekends doing Meccano and railway modelling.
Now we're having to start with a group whose exposure to engineering is playing Minecraft!

So anything you can glean from this forum, please share as widely as possible...
... down the pub would be a good start! 🍻 

@transparent

Posted by: @transparent

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I do know how to deduce the amount of the Randomised Offset to within around 10secs, but it can only be done whilst on-site and it takes many hours to conduct the required tests.

Using the billing information of 1.32kWh this morning when the 5kW inverter switches to battery charging at 00:45 and with an assumed background power of bp and x being the randomised offset in minutes 

1.32 = 5(15+x)/60 + bp/2

1.32-1.25-bp/2 = x/12

Let bp = 0.1

x = 0.24 minutes 

Every time I look at Octopus compare for the previous day’s consumption I will have to ask myself whether the Dishwasher or car charger was running!

Phil

That's an acceptably small delay for billing purposes @filipe
But we have to hope that the range of delays are indeed more related to the histogram I posted earlier, because that's what's required in order to operate the grid satisfactorily as we increase the proportion of renewable generation.

It's not just a matter of avoiding surges in demand.
There are a number of other factors in play, which are of concern to the DNOs and National Grid ESO:

• minimising losses due to phase imbalances
• reducing losses due to harmonics
• allowing time for ANM (Automatic Network Management) to switch off over-supply from generation sites on the distribution grid
• ... and hence keep the grid frequency within statutory limits

Posted by: @filipe

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Every time I look at Octopus compare for the previous day’s consumption I will have to ask myself whether the Dishwasher or car charger was running!

Yes, you can actually tell quite a lot about household routines by looking at the energy graphs, can't you?!

Here's an output from a grid-tied PowerVault battery I was trialing in 2021-22:

Posted by: @transparent

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It's not just a matter of avoiding surges in demand.
There are a number of other factors in play, which are of concern to the DNOs and National Grid ESO:

• minimising losses due to phase imbalances
• reducing losses due to harmonics
• allowing time for ANM (Automatic Network Management) to switch off over-supply from generation sites on the distribution grid
• ... and hence keep the grid frequency within statutory limits

One day we won’t be able to have electric motors, transformers or anything that causes a problem. We will probably have to have our own storage and once charged be isolated from the grid! 

Phil

@tim441 Tariffs have taken a fair bit of my attention over the last year, (I have been with Octopus Energy for one year today) and my circumstances have been very fluid in this time having added 8.1kWp of PV, first one Powerwall 2 and now a second, had an ASHP installed in February and upped our insulation last winter. Octopus Agile has been my preference so far (even though, just today, my newly renewed contract attracts double the standing charge!) and though I have glanced at some of the other offerings: Cosy for one, I am still of the opinion that with dynamic pricing that Agile enjoys, by the time I have taken as much advantage as I can of plunge pricing such as I have been enjoying yesterday and today, I am unlikely to obtain a better deal with any other tariff. We are retired and can adapt our demand to use TOU to our advantage and with 27kW/h of energy storage on top of the solar PV contributions, I am hoping that this winter we will be able to power the ASHP with mainly low cost energy from this tariff. I had been using Agile for the exported energy and noted the significant reduction in pence paid per kW/h in recent months and so have swapped to the fixed rate (15 pence per kW/h) for the summer but may review this if I have any significant amount of energy to export during the gloomy months but suspect I’ll not have enough to concern myself about. I’d be interested to hear how other readers have tackled this very complex subject please.

Octopus Tracker yesterday was just 11.66p for IMPORT and today 8.44p!!! I guess weekend rates with lower industry working, summer days with minimal heating or A/C .... and winds producing excess power has enabled that. Agile half hourly rates are negative for some periods.

So batteries emptied at 15p... and now refilling!

I have not checked exactly but afaik the average Tracker price since 1st Jan is around 20p and last couple of months 18p. 

I will stay with Tracker rather than Agile because it suits me best in winter (vast majority of my usage then) with ASHP that I use on weather compensation. So don't want to turn it off to avoid peak rates - smooth operation 24x7 is noticeably more efficient in my case and just one or two degrees setback overnight.

Fixed export 15p definitely best option for me.

Cosy, Intelligent etc don't suit me but everyone needs to look at own usage profile etc.

Have to keep an eye on T&Cs when switching tariffs. I think a switch away from Tracker means you cant switch back again for 9(?) months. 

@tim441 Similar rates here on Agile tariff Tim441, last few bills show average unit rate of between 18 -22 pence. Having the luxury of 27 kW/h of storage, I hope that this winter, I’ll be able to find a couple of periods in any 24 hours where I will be able to recharge the Powerwall battery at a low rates and thus ride through the peaks without resorting to the grid. Like ypu, I’m using weather compensation and the ASHP is on 24/7; I have only had the system up and running since Feb. 19th. but think I have my LWT etc. in the right ball park but am ready to adjust it in late November if the need arises; I had hoped to have a Homely Smart Thermostat and controller installed by now. The software requires more work before it can cope with my Daikin unit and a low loss header and secondary pump; I had hoped to be able to use Homely’s API for Agile which might have made the system even more efficient as the API should take the Agile rates into account in a similar way to MyEnergi’s Eddi. My ASHP is not running in the warmer months normally as my DHW is catered for by the Sunamp Thermino ePV 210 unit via Eddi. OK, I’ll own own up to being a SuperNerd who peruses the 48 daily Agile rates and like to think I am using the cheapest periods and take advantage of negative rates too! The Tesla controls do not allow for ‘on demand’ discharging as they are set to only export solar excess. Regards, Toodles