Hopefully shortly be joining this thread after watching for a while. 6kWp array on SSW 45 Deg roof and 10kWh battery being installed today.
Slight thread diversion but on solar diverters. The diverters I have seen seem fairly basic. Is there one out there that had functionality like this.
Multiple circuits with preference of use and load optimisation. i.e. Preference for circuit 1 (immersion 3kw). but once not daring any power go to circuit 2 (heater on landing 2kw). Also option to load balance e.g. we are exporting 1.5 kw, circuit 1 and 2 have been satisfied so swap preference of circuit 3 (2kw) and 4 (1kw).
Basically multiple channel highly configurable. I know roughly how I would make one but its quite a task and wondered if one was already available.
Not sure how happy you are with programming and stuff but have a watch of this video....
Otherwise not sure which ready made devcies do what you want. Maybe the MyEddi?
Not sure how happy you are with programming and stuff but have a watch of this video….
I've been doing it for nearly 20 years and some electronic stuff but I am definitely not happy with it but that's due to a slow mental breakdown rather than any lack of technical ability :).
Video link looks good thanks. I have an idea of how I could do most of it but was interested if there was something off the shelf to avoid the work! Amazed at how basic most of the ones I have seen are. I'll check out that edii one.
The Eddi and Zappi work by diverting excess export to a pre-determined path. I don't have an Eddi yet, but the Zappi picks up when there's excess and then starts charging the car when the value exceeds a certain excess. The car can only charge at 1.4kW minimum, so you can chose a % value of that 1.4kW for excess. Anything below 1.4kW and it will draw from the battery/grid to supplement the excess solar gain. The eddi sits in between and diverts to a heater first, then allows the car once the temperature of the heater is reached or the timer kicks in. You can scale the energy, but I'm not sure how much you can split or if you can have a second channel...
Can anyone suggest why my battery charging rate might be topping out at 3.8kW when the system is rated to 5kW on the DC side for charge and discharge?
Can anyone suggest why my battery charging rate might be topping out at 3.8kW when the system is rated to 5kW on the DC side for charge and discharge?
There will be two different limits - what the inverter can push into the batteries and the max load the battery pack can accept. Eg We have the same system as a neighbour but we have two battery modules and he has one. The same inverter can charge ours at twice the rate as his ie the battery pack is the limiting factor in this case.
I know each battery can accept at least 4kW as I've seen it do it, but somehow, now the splitter is in place, it seems to be hitting some kind of limit.
My initial thought was resistance in the cables, but I'm not sure that makes sense. The cable run to Bat 1 (12kW) is 2.5m, to Bat 2 (7kW) is 4m. Originally, the cables to Bat 1 were just over 1.25m... BUT, whilst the run to the splitter is now 2.2m, the power after the splitter is much lower...The cables are the right 100-120A spec.
What is the 'splitter'? An active device or just a cable join?
Maybe that is the bottleneck....
Its an active device called a RESU Plus from LG.
Well that would be my suspect, it all worked fine before you added it...
A few m of cable won't make any difference (unless you used 3A lighting circuit).
25mm2 4AWG pure copper cable, so no. It also shouldn't be hot enough outside to cause issues.
Is the “splitter” getting hot?
That's what I was considering. At those moments, it might have been be in direct sunlight, but equally, it's only 4 degrees outside and it's bolted to a sodding great big freezing cold wall.
from Page 35 of this doc:
It just looks like it's a passive device, just a copper bus bar with some connectors...
[url= https://live.staticflickr.com/65535/52721922060_6bac91ef47_z.jp g" target="_blank">https://live.staticflickr.com/65535/52721922060_6bac91ef47_z.jp g"/> [/img][/url][url= https://flic.kr/p/2ojRCCd ]Resu Plus[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
So can't see how it would affect things unless you have a poor connection or one battery is switched off?
No. There's a circuit board with power 12v power connectors and 4 RJ45 connectors that sit on top of that 48v coupling.
I assume that's just an Ethernet switch which allows the two batteries to talk to the single charger...
Is it possible it was cheap and on eBay because it was broken ?
I would try using a normal ethernet switch as if anything is going to be damaged it's that.
The 48v bit is unlikely to be damaged or if it was you would see a break where one of the connectors has snapped off the bus bar etc...
Do you have an interface where you can see system alarms etc?
It might have a fault code somewhere which will help diagnose what is going on?
The RESU Plus Connector was brand new from Segen. The battery was also brand new, but from ebay, but actually from a solar provider near Rochdale. The BMS showed no charge/discharge cycles. I've just looked at the inverter which is the only place you can see messages from the battery and there's nothing to suggest a fault. The BMS is stating that maximum charge/discharge is 91.9A, which is less than the 100 i would've expect, bust still doesn't equate.
I've e-mailed LG - hopefully they can help.
Both batteries did fully charge today taking in 15kWh whilst already having just under 4 in the packs, so it's working right from a capacity and management POV.
My 5.6kW PV array is surpassing itself... Interestingly enough I had only set the graph to max at 6kW. I have upped it to 7 so see if it goes even higher...
Nice. I think we've peaked at 5.8 from our 6.3Kwp array so far. Having a mixture of 100% own power days and 60%ish on the duller days. The app for our car charger is currently screwed due to a software update which made pushing the excess into the car harder as I couldn't reduce the charge rate. Elec meter is also stuffed so not getting credited for export.
Rj45 could well be a serial connection for commissioning / firmware updates as much as a ethernet one. If possible wee what chip it is connected to.
4.8 is. A new peak for me for a 4.14 system attached to a 3.6 inverter....
@daffy Only saw your post today. Your battery charge rate will have likely been capped due to the temperature (too cold).
We are also capped on a 3.6kw inverter however it is nice to see that the battery charges at a higher rate as it's all on the DC side. Not so good is the lack of battery control as mentioned earlier in the thread (solaredge battery). It's a moot point till the meter works and we can move onto the over night tariff.
I wonder if you can have a car charger or water heater on the DC side. That would be ideal for absorbing as much excess as possible.
@flaperon the temperature (of the battery at least) isn’t the issue. The battery has been happily discharging at 5kW even in colder periods.
There’s something in either the RESU Plus or in the paired batteries that’s limiting the current to exactly 65amps. That’s why it can be 3.4-3.8kW as the battery voltage varies.
The next time we have a VERY sunny day, I’ll experiment as I’ve now got a spare comm cable that I made to bypass the RESU PlUS, so I can check each battery independently.
Whilst charging and discharging is a pain as it’s now a little limited, the extra capacity has proven worthwhile.
Thanks to a sunny Saturday and moderately sunny other days, we’ve now been effectively off grid for 4 days. 10p with of electricity used, but almost 50kWh actually used. The extra capacity has helped get us overnight or acted as a buffer until decent gain the following day.
Question for Octopus smarties - how do you tell what energy you’ve exported? I can’t see obvious option on the meter display thing or website.
My 5.6kW PV array is surpassing itself… Interestingly enough I had only set the graph to max at 6kW. I have upped it to 7 so see if it goes even higher…
I was going to post the same, our 3.8 kW system is regularly peaking at 4.25 kW...
[url= https://live.staticflickr.com/65535/52767965219_5279fc0207_c.jp g" target="_blank">https://live.staticflickr.com/65535/52767965219_5279fc0207_c.jp g"/> [/img][/url][url= https://flic.kr/p/2ooVBDM ]4.25 kW[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
I had just assumed it was a reading error in the Huawei firmware, which seems to update itself almost every week....
Question for Octopus smarties – how do you tell what energy you’ve exported? I can’t see obvious option on the meter display thing or website.
On their app:
[url= https://live.staticflickr.com/65535/52767715331_e76e659b09_c.jp g" target="_blank">https://live.staticflickr.com/65535/52767715331_e76e659b09_c.jp g"/> [/img][/url][url= https://flic.kr/p/2ooUknn ]Exported Leccy[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
Thanks. I have the app now but it no show me that. Only just had their smart meter installed so maybe will take a little while to link up.
Only just had their smart meter installed so maybe will take a little while to link up.
Several weeks in my experience and it still thinks I have two gas meters with the same serial number, but only populates one of them with data and keeps asking for manual readings for the other...
Interesting video about the new Octopus Flux tariff here:
Includes a handy modeller to estimate your own benefits.
I had ignored this tariff and continued with Eco7 which suits us at the moment but our battery/inverter manufacturer has recently updated their software to allow forced export/discharge which it hadn't previously. Bit of a game changer.
@flaperon the temperature (of the battery at least) isn’t the issue. The battery has been happily discharging at 5kW even in colder periods
the new battery or your battery system ?
I have 2 batteries - one works down to 0 the other has a huff and throttles back when below 10.
Apparently I need firmware update on my slave battery. My installer may have only updated the master on install.
Apparently I need firmware update on my slave battery. My installer may have only updated the master on install.
I registered myself as an installer, then migrated my system over to my own sub domain, so I have total control eg updating firmware when I want etc.
Our installer was excellent at the physical install but self confessed IT illiterate, so couldn't answer any of my questions, so I just decided it would be easier to take over myself and Huawei were very obliging.....
I'm still a little wary of forced charge and discharge as they will significantly increase wear on the batteries and some battery manufacturers specifically state that their warranty does not include continuous grid charging.
My batteries and the RESU Plus are on the very latest firmware. The batteries individually will charge at 5/5 (98>100A) for the RESU 12 and 4.2/4.2 for the RESU6.5. This has been tested. The problem for some reason is with the RESU Plus or the Inverter>RESU plus interface. We've had several days now where the external temperature has been in the teens and it's made no difference.
I kinda assumed that since the Inverter will only output 100A or 5kW, that each battery would then charge as a percentage of that output and since the bigger battery is essentially twice the size, it would get 2/3rds and the smaller one, 1/3rd. Certainly when charging, unless the gain is VERY low, they both charge and then discharge together. Hence, even though the smaller battery has a lower max charge/discharge rate, in the combined system, it wouldn't matter as it would never actually use peak charge or discharge rates.
Is there an issue with a house with a perfect east - west at low angle (@20*)? The ridge runs due north -south. I am assuming the losses in winter would be really significant, even if both elevations had panels?
@ Daffy. That's interesting about the zappi and Eddi. I guess they are like the Solar iBoost device.
My situation is i'm technically inept, I have a 3.6kw system with no battery which is fairly ineffective (12 panels, half on either side of a East/West valley) on FIT. It's about 10yrs old and never had any funky bluetooth app etc so no real idea but being quite a power thirsty house I'd imagine even on the sunniest days we're not really generating much more than we use but like I say that's a guess.
My wife would like to switch the hot tub back on so my thinking was get a diverter that somehow plugs into an external submersible heater, and ideally something that connects to the immersion heater. Happy to pay for install but really don't want wires running all over the place so suspect with the minimal anticipated payback i'd be better forgetting the whole thing, cracking open a beer and just enjoying the hot tub as it burns large wads of money.
Anyone got any views please lol? (maybe that I'd be better spending money on adding a battery to my set up)
My installer has 40kWh of battery storage and uses that to force charge on an EV tariff and heat the hot tub every day.
He uses 60+kWh a day...
@footflaps we had both the old and new elec meters showing after moving to octopus. Eon next hadn't decommissioned the old elec properly. Took 5 mins on the phone for octopus to fix and while I was on the phone they booked an engineer to fix the not transmitting 'smart' meter.
Ah, interesting, thanks Daffy. I'm struggling to find anyone that wants to take my money - the industry seems very in demand! I haven't researched but I wonder if there's a restriction in the FIT terms to siphoning off the PV kw into a battery when I'm meant to be pushing it out to the grid.
I'll have another go as it would remove worries we have of power outages also, we have a small PHEV battery and an even smaller e-Moped battery that would benefit from such an install. I guess the sooner I do it the quick I get the benefits.
Interesting video about the new Octopus Flux tariff here:
Not that dissimilar to Octopus Agile, same shape, just fixed rather than dynamic...
We top up our battery every night between 3 and 5 am (unless it's over 60%) and then either top up on solar or just run the battery down during the day.
Not used any electricity in peak evening hours for months now.
On a 'bad' day, with no solar at all, and only a 60% charge, battery runs out around 11pm ish when we're only using 0.2 kW or so.
Well, the sun is down on the second wettest March on record and we've done okay. 366kWh generated. 46kWh Exported. That's partially due to my silly self limiting expansion pack (stupid 65A max), but also my wife refusing to make use of the sun as she's "too busy to put the dishwasher/washing machine on whilst working from home" Grrr!. There were around 3 really sunnt days where we generated about 26-27kWh and the batteries can only store 19ish, so we were never going to use it all.
We've apparently only imported 102kWh. So, £33 + the standing charge should see me under £50. £130 paid back...It's a long road to recovery!
322kwh here compared to 460kwh in 2022.
114kwh exported mostly as we only had one battery till about the 10th and my firmware was updated.
Imported 120kwh
Signed up to flux this morning as every rate except the peak is lower than OVO has just put their rates up to.
Although thanks to powermove our bill was 30 quid for march
Array size?
335kwh generated from 6kw array in the south east
50kwh exported
140kwh imported
My app annoyingly doesn’t aggregate months, just daily totals.
Not sure how accurate the numbers are from the app or how efficiently the battery provides generated electricity.
Aberdeen 5.3 array
4kw array Aberdeen
It’s definitely been sunnier in Aberdeen than in the south.
129kwh on a 3.2 array (small usable roof space) 5kwh battery. I’m happy with that as it was only installed on the 16th of this month. South Northumberland.
6KW south facing in a deep Welsh valley
304 Kwh generated in March with no export (only marginally better than February & 275 kwh and that was 3 days shorter!)
132 kwh imported from grid
so 304 @ 59p = £179 saved this month. Looks like there is a potential saving of well over £2K over the year.
59p a kwh sounds high?!
I assume welshfarmer may be on three phase business rates other wise 59p/kWh is having pants pulled down
.
Single phase, but business rates. My contract came up for renewal at just the wrong time. 59p was best I could get. I was getting quotes of over a £1.10 a unit in December when I had to renew. At the time there was no guaranteed rate relief for businesses and prices were going up daily (sometimes twice a day). I took what I could get for a 1 year contract. And there are no dual rate tariffs for small business users either 🙁
With the value of hindsight I could have stuck it out on a variable rate tariff which would have been nicely reduced with the business relief, and then looked to get a new contract now that the prices are back down to around 35p a unit.
7.2kW install on an E/W roof in Sunny Leeds… well I say sunny, it wasn’t particularly this month.
Install only went live on 5th March, so not a full months data.
However in the period 5-31st March we generated 307kW and put 170kW into the batteries.
Import from Octopus was 135kW which is a lot less than we would normally use and some of that was me testing our the forced discharge on the batteries.
We are on Octopus Flux import and just waiting for Flux export to go live in the next week or so.
Being new to solar, I am impressed how even with a fair bit of cloud you can generate a lot, and the E/W aspect works really well too, so south facing really isn’t important so much.
358kW from our 5.6kW array in March. Had a Raspberry Pi issue whilst we were away so lost almost 3 days of readings plus had snow cover for almost 2 days so final "recorded" result was 358kW, without the Pi dropout probably around 390kw, thats off 5.6kW array.
Our manufacturer recommends force charging to 100% regularly as this keeps the batteries in best condition. General consensus from those on the vendor facebook page (many of whom seem well informed) is to set the minimum SOC at 10%, force charge occasionally to max then let the BMS do its thing.
In my view when you consider the battery charge is constantly on/off during the day (possibly 00's of times) as the battery use against solar gain constantly changes then I think this must be the greatest risk to battery longevity. Anyway will be interesting to see how this pans out over the next few years across all manufacturers.
I have changed my overnight charging schedule and reduced it to 45 mins. (8.7kW battery and 5kW inverter) previously I aimed to have 100% when our Eco7 finished at 7:30 and some days I was feeding back more than we were using (only 1p difference in cost) but if I charge and wake up to 50%, even with the early morning kettle and toaster etc it can easily be 100% by late morning and only drawing around 300w so at some point it is fully charged well before the teatime rush.
This is 9am
First proper cloudless day in East Anglia for ages, been struggling to generate more than a few kWh for the last few weeks.
Looks like we'll break 20 kWh today from a 3.8 kWh install, which will be a new record (Dec '22 install).
[url= https://live.staticflickr.com/65535/52793371994_3babdcbf62_z.jp g" target="_blank">https://live.staticflickr.com/65535/52793371994_3babdcbf62_z.jp g"/> [/img][/url][url= https://flic.kr/p/2oraQcC ]Sunny day...[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
It has been sunny the last couple of days. Annoyingly octopus seem to be taking an age to set up my export tariff. I notice they have a deemed contract for when they can charge for importing, I wonder if I can do the same for exporting..
Over the last 4 days we have drawn 17kW from the grid and exported 104kW.
An additional battery would remove need any import but at 18p per kW import and 15p export the £1,500 battery purchase would take a long time to pay for itself.
Monday the best days solar since install at 34.30 kW
April has been good so far - 91kWh in the first 4 days. Yesterday managed to charge the house batteries and the car in a single day.
Is that with Octopus @surfer ?
Yes. On Eco7 at the moment but in the process of moving to Flux. I'd held off moving as our batteries dont have the facility to force discharge (do any?) but the rates even when exporting spare solar are very attractive. This is helpful to visualise.
Random question as I try to budget - is it cheaper to have integrated/whole roof array if you were going to re-roof a building anyway? Seems daft to pay for a whole roof of tiles then stand off a solar array...
61kwh so far this month for me in my small 3.2kwh array.
@surfer I can schedule my battery to force discharge on a schedule via my Solis Inverter it has three charge/discharge schedules. So far I’ve only used it for overnight cheap charging.
Solis integrate with Octopus in their app for pricing display so it’s not inconceivable that they’ll add Flux support via a firmware update.
@matt_outandabout - probably not cheaper, but certainly better.
Tiles and slates are only a few ££ and the cost of the trays alone will be £60-75 per panel. Then you’ll need additional fixings, metal work, etc.
Mine worked out about £2000 more for in-roof and there’s only around 250-300 tiles saved.
I think it looks better and there’s less likelihood of birds nesting or wind damage, I also get some light through the centre on the panel/tray. So my loft is now always light during daytime. In a full blue hue sort of way.
Quick question. We have an old set of solar panels on our home, installed right at the start (on one of the better generation tariffs). Anyway looking at how I can measure the amount of energy generated by the panels, since I am looking at getting some batteries installed to make better use of the energy that we generate.
Does anyone have some good examples? We have a basic inverter and meter, so it would need to be separate from those.
(I also know that before I install any batteries, I need to make suer that I don't impact our generation tariff.)
is it cheaper to have integrated/whole roof array if you were going to re-roof a building anyway?
if you are re-roofing anyway go for inline. Avoids pigeons nesting or gathering underneath on-roof panels.
There was a saving in moving to online for us over a re-roof and on-roof panels. We had a high slate-breakage rate (crappy Victorian slates) and 18 panels installed so a fair amount of slate ‘saving’. And a neater finish imo.
@surfer I can schedule my battery to force discharge on a schedule via my Solis Inverter it has three charge/discharge schedules. So far I’ve only used it for overnight cheap charging.
Solis integrate with Octopus in their app for pricing display so it’s not inconceivable that they’ll add Flux support via a firmware update
I have Fox ESS batteries and inverter. It looks like they are adding this as a feature (although it doesn't appear to work yet) Its unlikely I will export from my battery its almost all needed for self consumption in the evening and to get through to the charging window at 2am.
. I’d held off moving as our batteries dont have the facility to force discharge (do any?)
I can control charge and discharge times from Puredrive Batteries via the solis inverter app.
@bruneep which solis app is that one?
Is it Solis Cloud? It looks different to the UI have for the same functionality (Also Puredrive batteries)
That's the web UI on Solis cloud I believe.
Or at least it's the same as Solis cloud.
My app UI is horrific
1st was cloud app, this is mobile app.
I don't think its that bad 😉 need to get remote access from solis via their customer support
Ah right that make sense I never use the actual web app just the mobile app. I should It’s looks nicer 😁
I can control charge and discharge times from Puredrive Batteries via the solis inverter app.
Are you able to "force" discharge to the grid? For example dump all of the storage in your battery? If so what is the discharge rate? is it based on your invertor so discharges at say 3.6kW
The Foxess app has a "feedin" option which was added a couple of weeks ago but it seems to work as follows:
Solar > powers Home > Grid (none goes to battery) as oppose to Solar > powers the Home > Battery > Grid
So it exports the unused solar (which actually suits me as dont want to force discharge my battery) as oppose to actually exporting the saved power in my battery.
Yes, set the times you want it to discharge and the discharge rate can be set up to 100A
Discharge to the grid at 100A, that's 23kW. I'm surprised your DNO would be happy with that. Is that a standard approval?
Our manufacturer recommends force charging to 100% regularly as this keeps the batteries in best condition.
That's interesting. I had assumed the batteries were similar to EV batteries, and the recommendation from Volkswagen is not to charge above 80% unless you're planning trip that requires it, as it shortens the battery life.
We have the Huaewei system, I can schedule charge / discharge (to supply the house) and also there is something called 'force discharge', which I assume just dumps the battery to the grid regardless of our usage, but never tried it as don't see the point.
