@toodles Thanks Toodles.  I would think the Solis AI did this part not the OE one with one of these? Or perhaps that isn't the case

@vanq If you use IOF, they ‘take over’ compatible systems and use their own software to control export / import times from their own (Kraken) software. Toodles.

Posted by: @vanq

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@toodles Thanks Toodles.  I would think the Solis AI did this part not the OE one with one of these? Or perhaps that isn't the case

Yes, with the Solis you can use Solis Ai, at the moment, you cannot use the Octopus tariffs where you handover control of your battery system to them. 

I posted on this thread on what I found about Solis AI, you select the tariffs including Octopus´. I do not use Solis AI at the moment, as the tariffs I use are easy to manage with fixed time slots.  

Posted by: @toodles

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@vanq If you use IOF, they ‘take over’ compatible systems and use their own software to control export / import times from their own (Kraken) software. Toodles.

Yup. The OE ev charging intelligent tariff does not get in the way of my overnight charging. I have not yet had to raise anything with Octopus around that..

They did get it going for the agile export, not a simple thing with all the lobbying requiring paperwork, so I expected more hiccups. So the Solis is now contributing and I expect to recover the 250 I had to pay Octopus for the non MCS scheme by the summer! 

Posted by: @transparent

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Posted by: @transparent

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But does the Solis firmware actually implement anything useful?

What would happen if the BMS detected a cell failing to hold charge (premature ageing)
or a busbar connection with a higher resistance than the others?

Do you think Solis would retrieve that data for each battery with which they're claiming compatibility?

Would it be given an appropriate level of 'Fault Alarm' to enable the user to take appropriate action?

Because if Solis can't deliver a system which addresses fault conditions, then claiming 'compatibility' isn't particularly useful.

 

An inverter needs to be able to exchange info with the BMS about the overall battery bank soc, DC current parameters, high level battery faults, etc.

I can confirm the Solis S6 does that with my battery using Pylontech.

My point is that the communication between the BMS unit(s) and the inverter must fail safe under all circumstances.

The capability of the comms system to handle fault/alarms shouldn't be compared with the "nice to have" features such as SoC.

Posted by: @transparent

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Posted by: @transparent

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An inverter needs to be able to exchange info with the BMS about the overall battery bank soc, DC current parameters, high level battery faults, etc.

I can confirm the Solis S6 does that with my battery using Pylontech.

My point is that the communication between the BMS unit(s) and the inverter must fail safe under all circumstances.

The capability of the comms system to handle fault/alarms shouldn't be compared with the "nice to have" features such as SoC.

Agreed. If I had seen any signs of comms failures between battery and inverter (which I have not), I would have investigated. 

Solis will not engage in any discussion about Seplos.. If using one of the batteries on their list, then reassurance could be sought. 

@vanq 

If you have an EV and battery storage why would you not use an EV tariff?

Surely its way cheaper and more convenient?

Posted by: @bash

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@vanq 

If you have an EV and battery storage why would you not use an EV tariff?

 

Surely its way cheaper and more convenient?

Not necessarily, @bash.

My wife and I have an EV and battery storage but an EV tariff markedly cuts down on our convenience and debatably may be more expensive than what we're doing.

The issue is the interaction between multiple variables:

• Our EV usage is not that predictable; sometimes we're at home of an evening, sometimes one or both of us are out. Sometimes we have to leave earlier than other times, both in the morning and in the evening.
• The battery is only 6kWh and so cannot time shift that much. It's good for a couple of hours but not much more.
• The flip side to a good rate at EV charging times is an expensive rate at other times. Given we've another power-hungry device - the heat pump - we can't just optimise for the EV. Running the heat pump during Octopus Go peak hours at 31p/kWh (in our area right now) would make for a very expensive cold snap.
• All our kit is linked in to a central management system - Home Assistant - that can make intelligent decisions for us.

All that means our most approprate tariff is not an EV tariff but Octopus Agile (albeit that we're using the non-agile export tariff).

The EV tariff is very competitive and simple to use.

@majordennisbloodnok example is however very common. When the expansion of energy storage is too expensive or just not an option for whatever reason, it may not be worth/possible to adjust the imports and exports to whatever is the best option that the market offers.   

@majordennisbloodnok 

It is pretty much impossible for Agile to beat (even with HA automation) an EV tariff when averaged out if you have an EV and battery storage.

This is our bill for December.

Our average price per kWh is 6.57p (plus vat @ 5%).

The best thing is I don't have to do anything at all, no checking of rates or endless hours tinkering with HA (which I have tried to do).

I will have another tinker with HA once my heat pump is installed next week, but I'd already worked out looking into it previously, that it's a significant time consumer, even with an inquisitive and reasonably technical mind.

@bash, I have no doubt you're doing extremely well costs-wise with your strategy bearing in mind your routine in your location with your kit. You have to allow, though, that I know my situation rather more intimately than you do, and that the choices my wife and I have made are sound for us. The language you've used in the last couple of posts is one of absolutes - there's only one right way - whereas the reality is, I believe, one of balance of probabilities. Your assertion may well be right for the majority of people but not necessarily all.

One thing worth bearing in mind is that @toodles is a good example of someone who regularly checks the tariffs to see if a switch is in order. It may well be that an EV tariff could be more appropriate for part of a year and a different tariff works better during other parts of the year. Octopus seem to be happy with people switching up to once a month or so, so playing the tariff-switching game could add another dimension.

Bear in mind I'm not arguing against the strategy you're putting forward; I'm just uncomfortable with the stance that it's the only viable one for everyone.

@majordennisbloodnok 

Thanks for replying.

Yes you are correct, looking back at my posts, it can be inferred I was suggesting my way is the best way. That certainly was not the intention. It is for me (I think, time will tell on that) after countless hours and days planning my journey to an all electric household over the last 2 years.

I come from a financial background having spent many years in a global trading bank. There was always going to be bias towards the economics of our electrification journey.

Thankfully having come from a working class, needs must background, I am confident and capable with building work, which I also enjoy (in the most part). I am however, although incredibly interested, a bit overwhelmed with setting up Home Assistant to monitor everything! Hats off to you, as I can imagine to get your level of automation, it must have taken considerable time and well beyond my skill set.

I came to the conclusion my time was best spent laying cables, building Fogstar battery kits and doing the planning and heavy lifting an electrician doesn't really want to do, enabling them to come in for half a day to connect everything together, check and commission our system. I even did the DNO application for them.

I see ourselves on this forum as kind of trailblazers for the electrification of UK homes. I can't imagine there are many people who have installed 45kwh of battery only storage, largely by themself, or who have setup a complex Home Assistant network to automate their energy demands.

This was the point I was trying to make, although perhaps a little heavy handed, that there is another way.

I know our system isn't for everyone.

I'd like to think my first hand experience of how it can be done (perhaps differently) may be of benefit to others, especially as I am one of the few on this forum (perhaps the only) who chose to not follow the conventional wisdom that "solar PV is cheap, reliable, and guarantees a payback - it's the gateway drug of the energy transition." that was posted on another thread that I responded to.

Sometimes challenging or discussing differing viewpoints sat behind a keyboard can come across in an unhelpful way and agitate, as we all (in the most part), like to think we have made the right choice.

It's great we can chat with people all over the world, however if we met in person and had this conversation, I expect it would have been less tense and more productive (especially if we could see other peoples differing systems)!

Hopefully I haven't offended you or @toodles (or anyone else for that matter) as I'd like to hope we can all benefit from each others knowledge and wisdom in the future, even if we choose a differing path on the journey to electrify our homes.

@bash No offence taken at all, different ideas and views are all part of what makes the RHH forum what it is! Regards, Toodles.