MrTWales

I have 12 panels on a flat roof and no massive issues with shading, but for some times of the year the start and end of the day are impacted with the lower sun. The 12 panels are one single series so I was thinking about splitting into two 6-panel series, which may not actually cost any more as it's so simple (the installers are back today fitting an immersion heater and seem to be willing to do this as part of the install, but any extra cost would be small anyway). In theory optimisers would be better (?), though in my case the extra value would be pretty small. Given the extra cost would be a lot am I correct in thinking that it's just not worth it? I honstly didn't realise how much they cost until I did a quick search today. Thanks!

I got panels last October and 3 x 3.6kWh batteries. At the time, I thought - if it was binary as to a decent size or nothing - then it was kind of marginal in terms of cost, but there are a load of things to consider. Personally, I didn't care that much about the extra cost so got a decent sized battery and the price was reasonable (based on the other quotes I obtained). If you are prepared to spend extra as relying on the grid a little less is kind of fun, then go for it! As others, who know way more than me, have said though the marginal benefit reduces as the size increases (as it does for panels once you are past the point of getting enough on the best days). In the winter a decent sized battery never gets full and in the summer you find on most days that there is plenty of battery left in the morning. With my size it does mean that if I have a good day and then a bad one I can still usually get by. Eg if I have have 40% left in the morning so if we use 10kWh in the next 24 hours and there is 6kWh generated then it just about works, but this only really matters for a small part of the year. On the other hand, this sized battery covers a typical day even with hardly any solar so it would work perfectly if I can ever get on a Flux tarrif.

I'm taking it as a quirk that users can't really do anything about. When you say "net imported energy", this just means the total imported in a day? The energy to grid stat really is annoying, so I'm hoping to get on something like the Octpus Plex tarrif when I can as there would be a decent net export for some months. Our average consumption is around 10kWh a day, but would be more now due to the immersion heater.

Just to add to this, the app says the following. I think the battery ran out a couple of times with the biggest two spikes but they are the only times I think, though it must have been close on other days. According to the actual meter readings, the draw was 7.9 kWh for May so 0.26 on average per day. So it looks like the app slightly overstates this and overall, based on what others have said, this doesn't look like a bad result.

Very true - as far as I can see the only cost in doing that is the hassle. I'm all in for it, but need to have some work done to fit the smart meter in the meter box and get the MSC cert from the damn installers first.

Dammit! I meant 9.6kWh, and haven't been shamed for long enough yet for this to stick. I can't get used to capitals in the middle of text. It just feels all wrong.

Yes for sure, but it doesn't seem like it would be all that much worse anyway in the winter if you want to consider a whole year. In my case I have 9.6Kwh of battery (9Kwh that I can use) so charging between 2am and 5am should leave enough for the next day and almost always should last until the end of the highest rate period. And this is without considering the generation in the day.

This is Octpus Flux? I was only aware of this a day or so ago and I can't see any reason not change. I guess it's way worse in winter, but even then with a decent battery it should be OK?

Thanks a lot, that's really helpful. If my darn installers ever get back to me re installing the diverter then I'll see if they can do this for a few extra quid - otherwise I'll get someone else to do it.

Thanks - I'd be lying if I said that I understood that but it sounds like a simple job for an electrician?

Thanks, that seems like a lot. I think I just assumed 4kW as when I looked at the data there were a few discharge figures around there but it may be concidence.

Wow, that is a big area! I thought all meter boxes were tiny little things like mine.

Thanks - that doesn't look huge but it still may be a bit tight. I've asked them whether they could use a smart meter that Shell may install but I'm not hopeful.

Well, I asked Octopus and they said "The best way to do this would be to have your current supplier send a meter operator to you to assess if the available space is sufficient." I thougth that the smart meter needed to be installed by your supplier? I'm not sure what to do now - not sure that my current suppplier (Shell) will come and just check without actually planning to do an install.

You've got me questioning everything I thought I knew! I can see what you are saying but it does seem like consumption really is consumption (though how accurate it is is another matter). If I look at the history data it shows the following: it looks like the immersion flicked on and it took a while for the battery to discharge. As far as I can see, the battery can discharge at 4kW at least as I've seen this "pDisCharge" value on other days (I'm fairly sure that this is the limit). The chart uses 5 min incremements so I think some spikes can look bigger than they are.

Damn they are big. This would just be whatever Octopus want to install and I doubt I'd have any say (or even know what to say!). I'll ask them for some details but I suspect I'll be waiting a while for a reply.

Thanks, I'll have a go!

If it was consumption of 6kw I think the orange line would be at 6kw, with the solar/battery/grid making this up. That spike looks like those random (to me!) spikes that I see sometimes. What you say about the induction hob seems right in that this does cause some spikes, but I seem to get them anyway. I think the import as per the app slightly overstates the actual draw though, when I look at the actual meter readings. All I did that day was heat up my take away in the microwave!

Thanks a lot. I'll try to make sense of this later but it sounds like needing to get an electrician - but the thing is knowing what the tell them! There is a consumer unit in the mancave and I think when the stallers set the solar panels up they said something about removing the "man cave box" or combining it to save room if I need more space in there. I'm not sure I'll be able to get much from Octopus so I'd want to be sure that they can fit the smart meter they need as it seems like there is a waiting list.

I can't see the spike on the chart but I do have an induction hob! I thought it was only 1kw though. It's something I never ever use in the winter but it may be worth using now, so long as the import spike is only small.

Just checked and I've drawn 4.0kWh (THANKS TO STORMYTEA I'LL NEVER BE SO LAZY AGAIN WITH UNITS!) for the whole of April. I guess it's not too bad but it still annoys me a little more than it should.

I did wind up to 70, and I think it did make a big difference. Just checked and I've imported 4.0kWh for the whole month, and hardly any of it on the day of the chart. I was on my own that day and the immersion was the only thing with a large draw, so consumption was never high at any point.

I've been looking at the Octopus Flux rates and it may be a good idea - but it does mean having a smart meter installed. I think I'm right in saying that they couldn't install it in my meter box given the lack of space? The "Man cave" box feeds a games room that is external to the house, and this is where the panels/inverter/batteries are (post build of the games room). I wonder if the "house" and "man cave" boxes would need to be replaced with one box and I'd have to get this sorted before Octopus visited to install a smart meter?

Uh oh, have I used the wrong capitalisation? I can live with that given the dumb shit I do pretty much ever day.

Very true. All I have so far is a G99 cert - they told me that I'll get the warranties etc when the job is finished (which just needs the diverter to be installed) but I keep chasing them and getting nowhere. I held back £1k and have the diverter in a box, so they don't need to do much more really. What I'm wondering now is whether the diverter is even worth using for anyone on that Octopus tarrif if they have gas installed. I guess it may swing around with prices so it wouldn't hurt.