@chandykris yes I bet the EV is what really drives most of the saving, though I still would like to further optimise the energy efficiency. I am sure next winter I will be able to run everything more smoothly and save even more. Thanks!

When Octopus were paying me 15 pence per kWh for my export and charging me ~13 pence per kWh for importing, I arranged to export as much as possible and draw from the grid during those 8 hours of Cosy cheapest rate energy to charge the 27 kWh battery.

Later, OE increased the Cosy tariff and it became ‘marginal’ as to whether with the ~ 10% losses through the battery it was worth selling my solar and buying grid to fill the battery. I thought long and hard about the practicalities and the morals of this ‘arbitrage’ on a daily basis.

With the export rate having dropped below the buy price now, I have been re-configuring my Tesla app to ensure I leak as little solar energy into the grid as possible! Morally, I feel this is a very good thing to be doing and, as such, my grid consumption will drop a little. The amount gleaned from the Sun is not that great at present, and of course, the ASHP gobbles up what little there is from those 21 panels.

One can but hope that some sunnier weather is on the horizon and that a rise in temperature will allow the heat pump to snooze some of the time. We might then be able to spare some energy for export whenever the battery is fully charged.

I have heard rumours that OE are withholding IOF tariff from new contracts at the moment (this does not augur well does it!?). It is rather likely that this coming summer’s solar energy is going to pay less well than previous years have. Regrets, Toodles.

@toodles it’s a real shift when the numbers that once made sense for arbitrage suddenly flip, and now self-consumption feels like the only sane path for many.

On the IOF rumour, I haven’t seen official confirmation that Octopus is fully withholding Intelligent Octopus Flux from new sign-ups, but availability does seem tighter lately (some reports of it being temporarily paused or harder to join amid volatile markets and recent global price spikes from the Middle East stuff).

Standard Flux, I believe, is still open, and it offers decent time-of-use export peaks (around 29p in the 4-7pm window in some regions), so that might be worth a look if your battery can play nicely with it.

In the meantime, leaking as little as possible to the grid is smart household economics… interesting year ahead.

Morning Folks!

This is currently my winter-optimised set-up. I find that by stopping battery discharge at 300% end up recharging well overnight and having enough for self-consumption the day after without exporting when I need it. But perhaps may be improved?

@toodles hopefully Sun will cheer you up soon...

@editor When I check in Octopus website, it says Octopus Flux is temporarily unavailable. I wonder if you call whether it's still available, but at least not online.

@eliuccio What size batteries do you have? If you restrict battery discharge SOC to 30%, won't you be using from the grid at peak rates if you reach 30%? We only have 13 kWh batteries, so invariably end up dropping to nearly 10% every day in the winter. But, come April when HP is switched off and PV generation is in excess of 20 kWh, then we seldom go below 75%. But, for now we don't have the option.

If you haven't already, have a look at the Solar Optimiser tool on Tim and Kat's green walk website. You can try out different strategies such as self consumption, charge batteries with excess solar or with off-peak electricity, and then it tells you the best tariff by month. I found it fairly accurate and very close to my bespoke analysis using Octopus data downloads.

Hi, We are with E.on Next and expected to be able to download the 30 minute usage data in a similar way to Octopus but alas not. There isn't even any usage dta on tehir online web portal. The APP shows the data but there is no way to download it or even request it, it seems. They are saying we need to go through a SAR process but we seem to be going aroudna loop with them.

I did call them and spoke to a nice call centre worker, who said. No problem we will email you to data. Nothing happened so more calls same discussion, then a email arrived with our statement and no detailed data. This process with Octopus is trivial, you just tell it what data range you want and you get 30 minute data back. Maybe I am missing something in their app or web portal but I don't think so.

 Does anyone lse have this issue with E.on Next?

Cheers

Posted by: @antonical

↑

Does anyone lse have this issue with E.on Next?

Yes.  

I used data from Home Assistant and a Shelley to capture data last year and this year Im back with Octopus (not because of the data download, although it was certainly an irritant!).

@jamespa Just bizarre. This is our data. I really don't understand. Their app shows the usage data similar to the Octopus app, but there is no way to download it.

Come on E.on get with the program.

I have a shelly em50 on the network that monitors the ASHP circuit so do get realtime discrete power measurements in HA for the ASHP power draw. We had a new CU put in specifically for the plant room that the new plumbing tank etc. went into. 

Maybe we could start some kind of campaign to get E.on to get with the times.

Cheers

@chandykris

Thanks, that’s a fair point and I agree the “right” floor depends heavily on battery size and the household’s evening load profile.

In my case the battery is relatively small (5.12 kWh), so the 30% discharge floor is a deliberate winter compromise rather than “never use the battery.” I’m on a single-phase 60A supply (in the process of being upgraded to 100A) with ASHP + EV in the mix, and earlier on I found the inverter modes could cause the battery to be “spent” at the wrong time (especially around EV charging), leaving me importing later anyway. With the current setup (Battery First overnight, Load First daytime), the battery reliably recharges in the cheap window and then supports self-consumption during the day. The 30% reserve mainly stops the battery being completely flattened before it can actually do useful work when tariffs are higher and PV is weak.

You’re absolutely right that if I hit 30% early in the evening, I’ll import at peak rates. In my own case, the trade-off has been acceptable because: (a) the battery is small, so it wouldn’t cover the full evening peak anyway, and (b) keeping a reserve has improved predictability and stopped the system “misbehaving” on EV nights. When PV improves (and once heat demand drops), I’ll likely trial 20% again, because at that point the risk of ending up at 30% too early is lower and the opportunity cost is higher.

Also, totally agree with your seasonal pattern: once you’re in April onwards and PV is routinely in surplus, the floor becomes much less relevant because SOC rarely gets anywhere near it.

On the Solar Optimiser idea: good shout. I’ll give it a proper look. I’ve been doing something similar with Octopus downloads + my own tracking, so it’ll be interesting to see how closely it matches month by month.

Thanks!!!

I haven't received an official email yet, but saw on YT and online forums that Octopus is dropping IOG and Octopus Go rates from April. When I check on their website, it says Octopus Go is 7p off-peak and 34.5 p peak rates from 1st April. Intelligent Octopus Go is 5.5p off-peak and 34.5p peak. This is for 12 month fixed as Octopus are not offering variable Go for new customers. As we are on variable Octopus Go, not sure what our rates are going to be, maybe slightly lower. This is for the South East region.

Has anyone received an.email from Octopus yet? With peak rates nearly 6 times off-peak, the business case for home batteries makes more financial sense now. At these rates, I might stick to the current set up and not tweak for higher self consumption. As in increase self consumption by charging the batteries only from excess solar and DHW from solar.

Ive had email this morning from Octopus, signed by Greg

It’s well put together, correctly identifying me and that i’m a heat pump user with no Gas

The video embedded in it from Greg is worth watching as it informs why prices are changing

At the end of the email, my current and new tariff prices are correctly shown too

well done to Octopus