Circular reasoning (Rolfe's solar energy system)

[johnb80]

Octopus can't control an MG. So if the car refuses to charge between certain hours, surely there is nothing that Octopus can do about it!

No, it cant but it CAN control the Zappi which is whats setup here.

 

[Rolfe]

I think I'm probably fine as regards the midnight charge. It appears to have been that phantom schedule I hadn't seen, and have now deleted.

It's interesting the way the Zappi went straight for both the grid and the battery when the scheduled charge time on the MyEnergi app was reached. That is not good. I don't actually know what it did when Octopus did the scheduled charge I actually asked for, because the MyEnergy app was down at the time and the lost data never reappeared. I guess I'll find out at some point.

One question I still have about rewiring the setup so that the Zappi can't call on the battery is, is there a downside in that the battery can't tide the Zappi over short breaks in the sunshine and keep the charge continuous? I would have thought the car would simply pick up again once there was more surplus, and I think I've seen it do that, but I saw people in other threads complaining that when the sun went behind a cloud the car stopped charging and wouldn't start again.

 

[johnb80]

I think I'm probably fine as regards the midnight charge. It appears to have been that phantom schedule I hadn't seen, and have now deleted.

Thats good to hear.

It's interesting the way the Zappi went straight for both the grid and the battery when the scheduled charge time on the MyEnergi app was reached. That is not good. I don't actually know what it did when Octopus did the scheduled charge I actually asked for, because the MyEnergy app was down at the time and the lost data never reappeared. I guess I'll find out at some point.

It was actually a little different the way it works. The schedule started the charge at 7kW from the Zappi. Your inverter will have seen the house load increase by 7 kW and therefore start to do its job and ramp up its output to meet the extra 7 kW. Assuming your inverter is only 5 or 6 kW it will have max'd out taking the full amount from the battery, the remaining demand satisfied by import from the grid.

One question I still have about rewiring the setup so that the Zappi can't call on the battery is, is there a downside in that the battery can't tide the Zappi over short breaks in the sunshine and keep the charge continuous? I would have thought the car would simply pick up again once there was more surplus, and I think I've seen it do that, but I saw people in other threads complaining that when the sun went behind a cloud the car stopped charging and wouldn't start again.

Both my BMW i3 and our MG5 operate correctly with stop and start charge etc. wired in the way I suggest. In reality though, once you have your export tariff it wont be an issue anyway?

 

[Rolfe]

That's interesting. I really can't tell from the graph, as it all seems to happen simultaneously, presumably because the data are only updated every five minutes. I assume it's as you say.

You're probably right about it not mattering if I'm always using the overnight tariff to charge the car and exporting the sunshine at twice the price. But who knows. The damn thing has tried to suck my battery dry twice now (probably three times, given that it switched on at midnight on the 29th as well, although I stopped that pretty quickly, and that was when there were no data being captured) I'm not sure I want to give it another chance.

There's also the question of future-proofing. It's also arguable, what do I need the Eddi for, if it's cheaper to export the sunshine and heat the water with kerosene. But this is a long-term investment and goalposts can move, and flexibility may be needed to chase future variations in tariffs etc. Also, I can still envisage the odd situation where I might want to charge from the solar, even with the rules as they are at present. (And God knows how long its going to take to get this export tariff anyway.)

Oh, and another question. You've explained how it happens with the Zappi, but the Eddi is wired the same way and this doesn't seem to happen. There's sometimes a little blip from the battery when the Eddi is operational, but most of the time this isn't happening. Why is it only the Zappi that triggers this battery drain? Just because it's a lot more powerful?

 

[johnb80]

That's interesting. I really can't tell from the graph, as it all seems to happen simultaneously, presumably because the data are only updated every five minutes. I assume it's as you say.

Very likely, inverters generally respond in milliseconds rather than minutes.

You're probably right about it not mattering if I'm always using the overnight tariff to charge the car and exporting the sunshine at twice the price. But who knows. The damn thing has tried to suck my battery dry twice now (probably three times, given that it switched on at midnight on the 29th as well, although I stopped that pretty quickly, and that was when there were no data being captured) I'm not sure I want to give it another chance.

I did try to make the point BEFORE you had it installed how it needed to be wired to avoid this problem. I havent met an installer yet that knows how to resolve this issue correctly.

There's also the question of future-proofing. It's also arguable, what do I need the Eddi for, if it's cheaper to export the sunshine and heat the water with kerosene.

Highly unlikely that using kerosene will be cheaper than off peak electricity. EDDI you will use to set a schedule to heat the water off peak. You can also 'work the system' if you delay you car charging to peak time and set EDDI going at the same time. I always charge a car from 06:00 on Sunday mornings and Octopus always give me off peak while 11:00am so everything in this house is running and all the batteries charged as needed. Great for washday and sunday Roast.

But this is a long-term investment and goalposts can move, and flexibility may be needed to chase future variations in tariffs etc. Also, I can still envisage the odd situation where I might want to charge from the solar, even with the rules as they are at present. (And God knows how long its going to take to get this export tariff anyway.)

All of that can still happen.

Oh, and another question. You've explained how it happens with the Zappi, but the Eddi is wired the same way and this doesn't seem to happen.

Eddi is very fast to respond and has nigh on infinite steps of current it can take from 0 to maximum current of your immersion heater. It will follow the excess energy really well and divert it all to your tank if you so desire.

There's sometimes a little blip from the battery when the Eddi is operational, but most of the time this isn't happening. Why is it only the Zappi that triggers this battery drain? Just because it's a lot more powerful?

Remember Zappi isnt drawing the current, the car is so Zappi has to inform tha car what the maximum current is that it can take. The car then has to increase / decrease it's current draw from Zappi. Theres a lot more going on in the charging process and the currents are 2.5 times bigger than your immersion heater so when it does start to take it from the battery it can soon get wound up to max power output.

 

[Rolfe]

You did indeed make the point before I had it installed, and I tried to explain it to the installer. I wrote something you said on a slip of paper and showed it to him. He was fairly non-committal. I didn't press the point because for all I knew, it was something he knew already and I was trying to teach a professional his job. So we are where we are.

I don't honestly know how Eddi compares to kerosene. What I am noticing is that I have really hot water which I didn't before. (Maybe too hot!) I let my central heating installer set the timings on the water heater and never really looked at them. I suspect he was a bit conservative with the timings. I asked the guy on the MyEnergi stand at Everything Electric, and he said that kerosene can whack the power into a water heater much more than an immersion heater (which I didn't know) and he himself uses the kerosene water heater in the winter, so I'll see how it's looking come winter. I can always look at the timings set on the central heating system, which are simply a pain to change.

I'm pretty impressed with the Eddi. I'm off for a couple of weeks holiday, and if anyone burgles the house, at least they'll be able to have a nice hot bath. (Once they've removed the pot plants standing in it in water...) Certainly in summer I like the idea of turning the central heating off altogether and not using the boiler at all.

I just don't like the way the Zappi is so keen to drain the battery, even if it's not something I'd expect to encounter in the way I would usually use the system in the end. It was trying to keep the car charging from the battery all night at 1.3 kW, and that wouldn't have done the battery a lot of good over 12 hours.

My installer did say that he would ask some of his other clients with similar systems if they had encountered the same problem. I remarked that maybe they hadn't, if they just used the Zappi overnight on the Octopus cheap rate. It will be interesting to see what he says.

 

[Bam Bam]

I just don't like the way the Zappi is so keen to drain the battery, even if it's not something I'd expect to encounter in the way I would usually use the system in the end. It was trying to keep the car charging from the battery all night at 1.3 kw, and that wouldn't have done the battery a lot of good over 12 hours.

Sorry to hear that. This potential issue was one reason I wanted the same company EV charger and battery inverter. That had the downside for us that we aren't yet eligible for Octopus Intelligent Go, which is the best tariff out there at present.

One installer I spoke to explained it along the lines of 'you set the export sensitivity [or some word like that] higher for one product than the other.' I guess this was Johnb80's suggestion and it sounded to me like it would work, but it is a bit of a fudge.

It sounds like these kinds of products are now much more user friendly than they used to be. Nevertheless, there are still certain issues arising where different company products aren't able to communicate with one another.

 

[Rolfe]

I would imagine that John's fix would sort it.

My installer quoted for a Zappi first go out of the box, and I know he fitted a Zappi for my neighbour (because it's outside, God only knows why). I knew I could get Octopus Intelligent Go with that so I wasn't going to argue.

 

[johnb80]

One installer I spoke to explained it along the lines of 'you set the export sensitivity [or some word like that] higher for one product than the other.' I guess this was Johnb80's suggestion and it sounded to me like it would work, but it is a bit of a fudge.

Export sensitivity isnt quite what it sounds (thats not the term either LOL), you can set an export amount before Zappi will start to charge the EV eg 2kW for 40 seconds, once that threshold is met Zappi will start to enable the car to charge i.e. it tells the via the pilot signal you can take a maximum of 2kW. As the solar production increase so will the pilot signal and vice versa until either the car if fully charged or the excess power drops below the threshold for 'x' time. The fudge or work around is to set these parameters quite high for starting the charge and very low for stopping it.

The best way to resolve the issue which isnt a Zappi issue, it's an inverter issue is to make the inverter blind to the load the Zappi is taking. It's supply needs to be taken before the supply to the inverter and the rest of the house etc. By doing this the inverter is totally unaware of the Zappi load and wont therefore try to feed it from solar, battery or both. Zappi can still take excess solar if you so desire but that isnt the way to run it with current pricing of export tariffs.

In terms of priorities, it's easily setup in the MyEnergi app which way round the priorities are, literally drag and drop the Zappi or EDDI as required. I used to have mine set for Zappi first the EDDI second. The way it ran was EDDI started taking the spare solar until the 1.4kW threshold was met then Zappi would take all of the spare power. If the solar output dropped below the 1.4 kW EDDI would then take it until the threshold was met again and so on.

The whole issue is a simple misunderstanding of the how the whole system will work together and it's easily avoided but it happens time and time again. You will see many posts on here when people are talking about wallboxes if they have solar as well I chip in sounding like a broken record because the problem applies to all boxes when battery and solar is also on the premises except when like you the wallbox, battery and inverter are all from the same manufacturer, hopefully they can communicate between them to stop the issue.

 

[Bam Bam]

I'm referring to the MyEnergi app. That's the one that seems to be causing the trouble, and the one which had the hidden schedule I hope I have now nixed. That asks for your supplier and tariff, but it doesn't have Octopus Intelligent Go on its menu.

Boost seems to be the issue. I don't want any part of it, but I don't know what to set it at so it doesn't try anything. Obviously not "manual" from your response!

I just found this on the Octopus Intelligent Go FAQs and thought of this thread: ​

Why does my car start charging immediately after I plug it in?​

×
After plugging in your EV, it will charge for a short period before the Intelligent Octopus Go smart charging schedule takes over.
There are a few reasons why your car might continue to charge for longer after plugging it in:

1. The charging plan has started when you plug in, so all is according to plan! You can check the charging schedule in the app to check if this is supposed to happen.
2. Something else is causing the car to charge, such as a charging schedule in the car, or smart charging features on the charger. You should turn these off in order to guarantee smart charging.
3. Intelligent Octopus Go may not be stopping your charge because it believes your car isn’t at home. We currently identify ‘home’ as your car’s location when you signed up to Intelligent Octopus Go. If your car was not at home during your onboarding, then you will need to log out of your car in the Intelligent Octopus Go app and go through the process again while your car is at home.
4. Intelligent Octopus Go checks in on your car at regular intervals to monitor your charging status. If the car is plugged in just after one of these checks, it could mean up to 30-minute delay in us stopping the charge.

 

[johnb80]

I just found this on the Octopus Intelligent Go FAQs and thought of this thread: ​

Why does my car start charging immediately after I plug it in?​

×
After plugging in your EV, it will charge for a short period before the Intelligent Octopus Go smart charging schedule takes over.

Correct it does to assess the rate the charging system can operate at.

There are a few reasons why your car might continue to charge for longer after plugging it in:

1. The charging plan has started when you plug in, so all is according to plan! You can check the charging schedule in the app to check if this is supposed to happen.

Yep, the charging schedule is returned in about 10 seconds after plugging in.

1. Something else is causing the car to charge, such as a charging schedule in the car, or smart charging features on the charger. You should turn these off in order to guarantee smart charging.

Not in this case, Octopus is communicating with Zappi directly, not the car.

1. Intelligent Octopus Go may not be stopping your charge because it believes your car isn’t at home. We currently identify ‘home’ as your car’s location when you signed up to Intelligent Octopus Go. If your car was not at home during your onboarding, then you will need to log out of your car in the Intelligent Octopus Go app and go through the process again while your car is at home.

Not relevant, Octopus doesnt care where the car is when it's controlling Zappi.

1. Intelligent Octopus Go checks in on your car at regular intervals to monitor your charging status. If the car is plugged in just after one of these checks, it could mean up to 30-minute delay in us stopping the charge.

Again, not relevant when Zappi is being controlled by Octopus.

 

[Rolfe]

I did read that, but the problem was that the car went on charging for an hour. It was plugged in about six, no Octopus schedule was requested, and it started charging of its own accord at midnight. It continued to charge until I spotted it an hour later and stopped it manually.

I think the problem was that phantom midnight till eight schedule ithe MyEnergi app, which I have now deleted.

 

[Exdro]

It goes like this.

1. I really should get a home charger.
2. If I get a home charger, I need a variable electricity tariff.
3. A variable electricity tariff will make my daytime usage more expensive.
4. The answer is to get a home battery and fill it with cheap electricity overnight.
5. Look at your roof, if you have a home battery it would be criminal not to install solar.
6. That will be £13,700 altogether.
7. But I could buy a hell of a lot of electricity for that. Um.
8. But I really should get a home charger.

How do you get out of this loop?

Buy a home charger. I’m now faced with having to replace my EO Mini Pro 1 charger which has been declared OBSOLETE, four years from being installed. EDF are sitting on the complaint. EO have offered 24% off the cost of a new chargerI am reluctant to use any of their products again). This has been an unexpected hidden cost of EV ownership. Surely a charge point should have a greater life expectancy than four years. Any comments or advice welcomed!

 

[Bam Bam]

Buy a home charger. I’m now faced with having to replace my EO Mini Pro 1 charger which has been declared OBSOLETE, four years from being installed. EDF are sitting on the complaint. EO have offered 24% off the cost of a new chargerI am reluctant to use any of their products again). This has been an unexpected hidden cost of EV ownership. Surely a charge point should have a greater life expectancy than four years. Any comments or advice welcomed!

When you say it is obsolete do you mean it is no longer supported but still works? Or that it is has stopped (or will soon stop) functioning?

I fear that with so many charger companies being set up some of them will go under and their products will no longer be supported. Hopefully their products and apps will stay working for a long time even so.

 

[Exdro]

When you say it is obsolete do you mean it is no longer supported but still works? Or that it is has stopped (or will soon stop) functioning?

I fear that with so many charger companies being set up some of them will go under and their products will no longer be supported. Hopefully their products and apps will stay working for a long time even so.

Software support was withdrawn unilaterally by juucenet in February. The unit has not functioned in any way since then. I am told that it was an obsolete unit from early February 2020. Mine was fitted then, possibly one of the last units on the shelves. It was highly promoted by EDF at that time. I am extremely annoyed that a large company can just wash their hands of a product that they sold. EDF passed the buck to EO who have blamed the software company. EO advised me to have it “looked at” . EV Domestics arrived, after a month, tested it, could not find any inherent problem and advised me that it was an obsolete unit. Why they couldn’t tell me that over the phone beats me. The call out charge for this advice was £114.00 payable immediately! Currently awaiting further input from EDF. Thoroughly fed up having car constantly on charge via granny charger.

 

[Bam Bam]

Software support was withdrawn unilaterally by juucenet in February. The unit has not functioned in any way since then. I am told that it was an obsolete unit from early February 2020. Mine was fitted then, possibly one of the last units on the shelves. It was highly promoted by EDF at that time. I am extremely annoyed that a large company can just wash their hands of a product that they sold. EDF passed the buck to EO who have blamed the software company. EO advised me to have it “looked at” . EV Domestics arrived, after a month, tested it, could not find any inherent problem and advised me that it was an obsolete unit. Why they couldn’t tell me that over the phone beats me. The call out charge for this advice was £114.00 payable immediately! Currently awaiting further input from EDF. Thoroughly fed up having car constantly on charge via granny charger.

Extremely frustrating for you.

What's more this kind of thing is going to put other people off getting an EV.

These units are a big expense for people that need to last years.

People will go with brands they have heard of and therefore trust, like their energy company, so if those big companies are letting people down like this then it is really very poor.

I hope you can shame EO into doing more than they are. It sounds a bit like mis-selling on the part of EDF.

 

[Exdro]

That is our plan. Get the EV charger fitted, smart meter, and get onto OIG. Then use timers to run all our major appliances after 11:30pm. Running the washing machine and dishwasher at that time outweighs any other electronics used during the day by a significant margin.

Our boiler is approaching 30 years old, when that finally gives up we will get a heat pump fitted too and ditch gas entirely.

Looks like you are going the same route as we have. Heat pump works well as long as it is properly sized and fitted. Worth while installing solar panels with battery storage along with solar charging for your car. Word of caution. My EO charger failed with no traceable faults after 4 years. An expensive mistake as both EDF and EO are not interested in investigating why it failed and have only suggested replacing the entire unit with an updated version.

 

[T1 Terry]

Looks like you are going the same route as we have. Heat pump works well as long as it is properly sized and fitted. Worth while installing solar panels with battery storage along with solar charging for your car. Word of caution. My EO charger failed with no traceable faults after 4 years. An expensive mistake as both EDF and EO are not interested in investigating why it failed and have only suggested replacing the entire unit with an updated version.

About the only suggestion I can make is look for a retired technician or group of them via the ... no idea what they cal it over there, it's "The Men Shed" over here.
Another possible is an electronics college or uni teacher that might take it on as a class project to sort the problems and come up with an app that will bluetooth to your phone.
Do you have an electric vehicle association over there like we have in Australia? Some very cluey people on there, one of them is a moderator over here I believe

T1 Terry

 

[Exdro]

About the only suggestion I can make is look for a retired technician or group of them via the ... no idea what they cal it over there, it's "The Men Shed" over here.
Another possible is an electronics college or uni teacher that might take it on as a class project to sort the problems and come up with an app that will bluetooth to your phone.
Do you have an electric vehicle association over there like we have in Australia? Some very cluey people on there, one of them is a moderator over here I believe

T1 Terry

Tx for tips.Still in negotiation with EDF. They are having a rethink after I suggested that I might go to the Ombudsman.This forum is also good for advice. Might discover perhaps others have had the same problem and see how they tackled it.

 

[Bam Bam]

@Rolfe Saw this video and remembered that you said you've got oil heating: