Which Octopus Tariff

The honeymoon is over and my nice 24 month fixed tariffs are about to end 🙁
About a year ago, we added Solar and a battery then started a 12M fixed export, recently renewed at the 15p rate.

I'm really struggling with the options, we have a PHEV so some charging of that needed and an 8.2KW battery, since the firmware upgrade, we are mostly running off grid now, especially on a sunny day so making hay.

Octopus have offered a fixed 12M or a variable but I look to also have many other choices, what do others think?
I can do some automations if I have to but prefer life simple so am thinking Flux for now and switch to something better if the rates improve. The new flux seems a little limited and I don't really want them on my system unless it's really worth it. I can't have IO, the car/charger isn't compatible and Go means low export rates so maybe in Winter but what about tracker, is this a real pain to implement and how quick can you get off if it gets expensive.

Octopus Flux - best export rates (19+ p) plus some extra time for a top-up at night.
If you really want to go full ahead there is a thread about running automation on Raspberry Pi which takes into account Solar predictions and then forces exporting during peak if there is a sunny day ahead (which can add an extra pound or two a day).
But even without I'm getting around 100£ back (5.2kw PV 8.2 Battery ).

ted Depending how much you charge the PHEV and how big your array is, I'd say flux or agile will be your best options.

Array is 6.8 and the car is charged maybe twice a week so about 30 kW worst case. I hadn't looked at Agile as the historic pricing didn't look too good, will take another look but it looks like Flux for now and see how things go.
Thanks

ted flux for the summer when you're exporting a lot and go/intelligent (lose the good export rates) for the winter when you aren't really should work

I'm actually thinking that Agile for import and leave my export on the fixed 15p I already have. I lose the 19p of Flux but gain the cheaper Agile import prices, Flux is still a little expensive during the day at 30pish and Agile seems to beat this. I can do this can't I? What is the standing charge for Agile, I can't see to see it anywhere?

We’re on Flux (import working OK, but still waiting for the export to be setup 😡)

Looking to the winter though am unsure whether to remain on Flux or to change. We have an ASHP so have high demand every day, typically 30kW although this may now be lower as I’ve turned on the AI temperature compensation settings.

With Flux I think I’ll be paying about £10 a day, could get this down to about £8 a day by charging the batteries overnight and in the afternoon to get through the Flux peak period on batteries.

Tracker scares me, the thought of having to pay 80p/kW to keep the house warm. I have been looking at Agile as the prices have a nice downward trend, but what will happen in the winter? Last December/January average Agile prices were 50-60p/kW and peaked at 80p/kW. Big ouch.

We don’t have an EV so Go or Intelligent isn’t an option. Maybe Cosy; need to do some more modelling

Tracker & Agile definitely worth consideration - but agree need to understand how they work and risks.

Tracker average this year since 1st Jan is around 20p I think and currently mostly around 16 or 17p (15p today!). Exceptional costs last autumn/winter are unlikely to be repeated - and if it goes that way you can switch away from Tracker/Agile quickly without penalty.

With my ashp i prefer to keep it going 24x7 (with weather comp) so Tracker best for me.
Fixed export definitely best for me

You can bail from tracker at 2 weeks notice. I'm running Flux and Tracker for gas with an EV. For the sum of gas and electricity import/export including daily charges, Octopus paid me £48 in June, paid me £20 last month and I'm up so for this billing cycle. 2x9.2, 5.5kW on the roof.

The below is great for tracking prices by region and type. Scroll down to the 30 / 365 day graphs.

https://energy-stats.uk/octopus-tracker-west-midlands/

ted agile is 42p a day I think. Flux is 48p. Think octopus compare shows standing charges.

ted might be worth looking into HA as well if you go down the agile route to automate the charging.

I'm in the same state with my fixed 24M contract expiring in Oct. GivEnergy seem to link via an API to the Octopus Agile tariff to maximise benefits - export or use battery when prices are high, use/charge when cheap. Has anyone any experience of this? Presumably GivEnergy have done some testing so should be able to provide some sample results?

thewhalw21
I do need to look at HA, will read the posts, looks like there are a lot of options, I like the local HA option but also maybe a backup online option. Hoping to learn once we are on the new tariff.

Tim Adams Tracker average this year since 1st Jan is around 20p I think and currently mostly around 16 or 17p (15p today!). Exceptional costs last autumn/winter are unlikely to be repeated

Tracker and Agile were in the 50/60/p day price range in the first half of December 2022 which is when it was bitterly cold so demand would have been very high. I’m worried that another very cold snap would drive prices towards the same sort of level, and yes can change away, still get stung for a while.
I’m wondering what changed around Christmas time and why the prices for both Agile & Tracker dropped to 30p range. Past performance and all that, but why might the same not happen again this winter? I’ll have to see if I can find what the forecast wholesale rates are for next winter which should take account of predicted demand, state of Europe gas reserves, etc.

I hadn’t been running my ASHP 24x7. Been using it more like a conventional system, on when required in the afternoon and evening, but starting earlier as the lower flow temperature means it takes longer to warm the house up. This approach had been adopted as the early days of the heat pump we’d had it on 24x7, the house was too hot overnight and the electricity bill was 50, 60kW/day. Running it just when needed it was more like 30kW in winter.
Towards the end of the winter this year I was adopting the 24x7 running, had reduced the flow temperature and turned the weather comp on.

Even if I keep the ASHP on 247 I am definitely looking into automating my battery charge and discharge to benefit from the tariff cheap periods. Looking at the moment for a suitable tiny PC to run Home Assistant.

geoffreycoan we initially used our ashp conventionally as our installer set it up like that... with high flow temps.
but gradually lowered flow temps and finally went with weather comp and 24x7. Works best for us.

The biggest indicator of future wholesale prices can probably be guided by the Gas Futures prices as can be seen here. I've picked put a few numbers to highlight:

https://www.theice.com/products/27996665/Dutch-TTF-Gas-Futures/data?marketId=5600523&span=3

A few takeouts (approx numbers):
SEP 23 CONTRACT
Aug 22 = 150
Dec 22 = 140
Aug 23 = 30

https://www.theice.com/products/27996665/Dutch-TTF-Gas-Futures/data?marketId=5733530&span=2
WINTER 23 CONTRACT is probably a better guide?
Aug 21 = 20
Dec 21 = 35
Feb 22 = 50
Early Aug 22 = 142
Late Aug 22 = 280 (panic buying by Europe & building stocks)
Nov 22 = 107 low
Dec 22 = 146 high
Jan 23 = 80
Mar - Aug 23 = 45 to 50

WINTER24 52.450
WINTER25 44.500

Last Dec we had a perfect storm that included:
Low winds (so less wind power)
High gas prices (stock worries too)
Cold temperatures across UK (& much of Europe?)

So I will watch these futures as my main indicator.

There are similar contracts for electricity futures.

I'm sure the power companies will have been using these futures to help protect both themselves and consumers from volatility.

With Tracker currently typically around 40 to 45% cheaper than standard prices there is a decent buffer - but needs to be watched

Tim Adams This is really useful and interesting, thanks Tim for your advice and input.

Just to confirm I understand the futures graphs correctly, taking Winter 23 contract as an example, this is a futures price for buying gas at any time in “Winter 2023” (which will be defined somewhere but would cover most of the ASHP high demand period). Selecting that graph, then clicking 1 year or 2 year, you can see the price you would have been committing to buy gas at depending on when you signed the contract.
Taking your examples,
Signing the contract in Aug 21 for buying gas in Winter 23 (i.e. over 2 years ahead), price = 20
Contract signed Dec 21 (2 years in advance), price = 35
Signed Feb 22 (UK war started), price = 50
…
contracts signed March - August 23, price = 45 to 50

Sept 23 price for gas, contract signed in Aug 23 = 30

So the expectation is that there will be a price premium on gas prices in winter 23, but only something like 50% up on current prices. Always the risk of completely unexpected events but the market predictions are nothing too awful.

I was wondering then about why choose tracker and not agile?

Agile I would have expected to be more beneficial if you have reasonable battery storage as you can charge in the cheaper periods and avoid the peaks. Tracker is going to give a smoothed average over the day and so would (I anticipated) be slightly more expensive.
But looking at the graphs on https://dashboards.energy-stats.uk/d/5cZqqmf4z/user-dashboard?orgId=1&var-area_name=Eastern_England&from=1672531200000&to=1675209599000 that just doesn’t bear out.

Average electricity price over January 23:

Tracker average 24.1p/kW
Agile average 28.2p
Agile off-peak average (excluding 4-7pm) 27.2p
Agile peak average (4-7pm) 34.2p

So yes, making use of the battery and being smart about when you charge can reduce the price paid on the agile tariff, but tracker is cheaper.

Similar picture on subsequent months through the winter, tracker is approx 5p/kW cheaper than the agile average and looking at the daily price spread, tracker is pretty much always cheaper than the lowest agile half-hourly rate.

In the summer the agile half hourly prices have more spread, The agile average (all day or off-peak) is still higher than the tracker price but there are periods in the day where the agile half hour price is lower than tracker (sometimes the price is even negative), so the agile could be better than tracker. However solar is supplying almost all of our energy at the moment, we’re only pulling from the grid when the house demand exceeds the inverter capacity or late at night after a dull day when the batteries haven’t charged up. So just not worth it for us.

Very interesting, not what I was expecting. I’ll do some more modelling with the garydoessolar model but I’m much more positive about moving onto tracker for the winter now. Thanks Tim,

geoffreycoan yes, that's my general understanding on the Futures too.

Big reasons that Tracker suit me more than Agile:

1. I have a large 16kw ashp.... which I run on weather compensation.... 24x7 ... with 1 or 2 deg setback overnight.
2. But my Gen1 hybrid inverter will only charge/discharge at 2.6kwh - which makes it impossible to fill the batteries (3 x 8.2kw) at offpeak rates
3. and as discharge is limited to 2.6kw as well I will need to buy some elec at peak rates too

Tim Adams We’ve got a similar setup to you, 2x9kW = 18kW ASHP which we will be running on weather compensation (or as LG confusingly call it, “AI mode”) 24x7. We set back 2 degrees from midnight to 18 degrees C but weren’t increasing it to 19 degrees until about 1pm and then 20 degrees at 4pm as the house was OK during the day.

We went through progressively reducing the flow temperatures from the installers 55 degrees setup to 48 degrees last year with the system being on for increasing periods of time, ending on 24x7 and turning weather compensation on, but we only got to that config at the start of May so not really been able to see the effects of it in the deep winter.

We have a 10.4kW array fitted so there’s 2x 5kW Gen 1 hybrid inverters, but only 14kW of batteries (9.5+5.2). We’ve therefore a higher discharge rate with both inverters, but the batteries weren’t enough to run the whole house and the heat pump in the winter so will have some peak rate demand as well. I did look at the economics of adding a further 9.5 battery but with approx 10p/kW peak/offpeak price differential it’d be something like 24 years to payback the _£4k investment.

VERY similar! Ours is also LG... Therma V.Our installer also setup with 55deg (later told me they always do that to save being called back for "not working" if low temp or AI mode). I feel installers really need to help educate us customers! MCS may need to insist on it?

Last winter I too gradually lowered flow temp before biting bullet with full AI mode and 24x7 I think mid Dec. Definitely seemed better all round. Very comfortable .. and I feel lower elec usage. Not 100% sure I've got all settings right even now. DHW is just 43deg and flow temp often low 30s with upper 30s when cold.

At home all day so 21deg target mostly if not active but with quite a bit of glazing we get solar gain if sunny so those days knock back thermostat. Overnight lower 1 deg if very cold ... 2 deg otherwise. Unused rooms & bedrooms 16deg.

Tim Adams I feel installers really need to help educate us customers!

Unfortunately, they don't get properly rewarded for that.
But if someone on here could set up a YouTube outlining all the various issues and solutions that have cropped up on here in the last couple of years, I'm sure they could make quite a nice income from it...

@Tim Adams
An update on what we did r/e changing tariff.

I stayed with Flux for longer than some other people on the forum did. Installed predbat in home assistant and got used to configuring it to work with Flux ahead of winter. As solar was dropping off we were starting to need overnight charges to run us through the day, but once I turned the ASHP on in late October (a month earlier than last year), it was clear I’d need to change.
Did a lot of spreadsheet analysis looking at all the tariff options, favouring Cosy, Tracker and Agile and in the end we moved to Agile on 25th October.

Happy with the decision. According to Octopus Compare, over the last month (so 10 days pre-ASHP being on and 20 days of heating), comparative costs:
Flux £157
Cosy £160
Tracker £120
Agile £106

Typically around £5 a day import which I’m happy with. Octopus have left me on Flux export so getting a bit of evening peak export as well.

I am running the ASHP 24x7 with weather compensation on. Flow temperatures seem to be around 30 degrees and the house is pretty comfortable. Definitely using less electricity on the ASHP than I was last year

geoffreycoan interesting to see - thanks for sharing. What temp do you set DHW?

Do you manipulate usage through programmer/thermostat to avoid peak Agile charges? Or just by using the batteries to fill cheaply off-peak and use batteries during peak?

We continue to use Tracker import and Fixed 15p export. Approx 1st Oct to 31st Mar we don't export as we use all we produce.

As we now have an ev as well its not easy to make comparisons but I try and keep monthly data on totals imported and exported, PV prod, ashp usage, ev usage to help build up the picture. Hot tub setup only for a month this year and will not use over the winter (2022 we used it for much of the year at unnecessary expense!). Data will build up over next year or 2 to provide useful comparisons I hope.

Overall very happy with the way ashp is performing with weather comp/AI... also flow temps in mild weather low 30s - rising to high 30s in colder weather (which we have not had yet this winter).

DHW set to just 43deg is fine - no shortage hot water - and still add cold to showers/bath. Hysteresis is set to 4 deg and seems fine - but i'm not sure if its worth changing that a bit?