lordnoob Posted August 27, 2019 Share Posted August 27, 2019 Hopefully you guys could assist, been lurking in the dark for a while now and finally comfortable with asking the questions without seeming like a complete noob. I had solar installed by a local company probably about 5 months ago already, however they did not have the ICC software which i managed to install and started actually checking out the finer details of my install. I noticed that there might be a fault in the way my system is setup because every time just after 12 there is a big drop in my PV yield through the system. Because I live in a complex I did not make use of the full roof space and ended up having them install 4 of the panels on the west facing side. But those who know ICC will also know the relative graph values, so I have been watching these values and every time those 4 panels on the west start catching the sun it pulls my PV yield down as well as the Amps. I am waiting for the guys to get hold of me, but any recommendations as to what the problem could be ? My assumption is the way the panels are wired . . . . Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 27, 2019 Share Posted August 27, 2019 (edited) How are the panels connected for a start? Each array into its own MPPT? Or connected together somehow? Which charge controller are you using? It can be that your batteries are charged at that point so there is nothing for the power to do? Does your geyser come on at midday? Edited August 27, 2019 by DeepBass9 Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 Currently making use of the Axpert King 5kw, this is being used to charge the batteries and run the whole system. As for the wiring of the system, I am waiting for the guys to get back to me so I can see what i happening, short of climbing on the roof to see. Yes, Geyser comes on, but pulls max 2000 watts at a time - the load from what I can see from ICC is pulled directly from the batteries first. Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 27, 2019 Share Posted August 27, 2019 I'm not sure about the Axpert settings, but I can see that there is only one MPPT on the unit. The other array should be on its own MPPT, do you have another charge controller for that MPPT? You should see that on the invoice for the installation. Is this a grid tie or off grid installation. And most importantly perhaps, how would you like it to be working, what is the system supposed to power and when? Quote Link to comment Share on other sites More sharing options...
Guest Posted August 27, 2019 Share Posted August 27, 2019 25 minutes ago, lordnoob said: Yes, Geyser comes on, but pulls max 2000 watts at a time - the load from what I can see from ICC is pulled directly from the batteries first. Perfectly normal. Takes a few seconds for the MPPT to adjust to the new higher load. Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 27, 2019 Share Posted August 27, 2019 PV volts, PV amps. Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 35 minutes ago, Pietpower said: Please explain the three graphs. First one is pv yield, second and third one? With the first one being PV yield I would also bet that your geyser switch of at 12pm not taking any more load. Then after 12 it will only produce what you use in the house and to charge batteries. That could explain it, I never thought of that, guess an easy way to test is change Geyser timing to the afternoon and see the effect. Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 @DeepBass9 Basically I just want to understand why there is such a huge taper off into the afternoon, but as per above I want to check if the load has anything to do with it because the battery should be fully charged. Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 27, 2019 Share Posted August 27, 2019 (edited) It looks to me like your batteries don't discharge much overnight. Up to the point I've marked it looks like they are in bulk charge, and then they go into absorb (stop taking so much current you can see that on the amps graph). Then your geyser comes on and uses mainly solar power directly, then it goes off and the batteries go back to absorb charge. They should ideally reach float charge state in the later afternoon where the volts will be lowered and keep the batteries topped up. They may do that but you will need to look at the battery volts graph to see if that is occurring. Do you have two MPPTs? The jagged pattern on the graph can be from the two units changing settings at slightly different times. Not a problem though. What sort of batteries are these? I would just double check the charging voltages and other settings to make sure they are correct. Otherwise the setup doesn't look too strange. So to summarise, it looks like your PV power drops off because your batteries are getting get full. Boil a kettle and put it in the fridge to solve that energy wastage. Edited August 27, 2019 by DeepBass9 Quote Link to comment Share on other sites More sharing options...
___ Posted August 27, 2019 Share Posted August 27, 2019 1 hour ago, The Terrible Triplett said: Perfectly normal. Takes a few seconds for the MPPT to adjust to the new higher load. Yup. The MPPT runs at a non-optimal point on the power curve because it is voltage limiting. Then the voltage drops and it has to find the maximum power point again. Cheaper MPPTs simply start from zero. The better ones will scan from where they are, and the really good ones remember the last MPP and start from there. Quote Link to comment Share on other sites More sharing options...
Solarphile Posted August 27, 2019 Share Posted August 27, 2019 59 minutes ago, DeepBass9 said: Boil a kettle and put it in the fridge to solve that energy wastage. Are you serious??! Blowdart18 1 Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 What so when I need boiled water I can just take it out the fridge again . . . Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 27, 2019 Share Posted August 27, 2019 (edited) LOL, what else can you do? Its now 12, my batteries are in late absorb, at like 95% charge, what should I do with the extra power? Eskom doesn't want it. Edited August 27, 2019 by DeepBass9 Quote Link to comment Share on other sites More sharing options...
Solarphile Posted August 27, 2019 Share Posted August 27, 2019 26 minutes ago, DeepBass9 said: what should I do with the extra power? Have some sort of relay that diverts the solar power (when batteries are in float) to a DC element in your geyser. Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 I feel like a complete blond now, I see that as the battery is approaching full charge and the load on the house stays stable the system is pulling less power so obviously the PV load and the amp starts fluctuating. Popped onto the system now to check and it started doing its funny graph thing again even though the geyser was off about an hour ago already. So next question, I would obviously want to maximize this PV production, apart from running appliances during this time could I get another set of batteries without upgrading to much. Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 Thanks @Pietpower Got all the info at home, so just trying to find it out Yes using a bit of Eskom power, the batteries unfortunately don't last through the whole night at the moment and its not really for a lack of trying. We have snake cases so everyone is on heat pads during the winter. Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 3 minutes ago, Pietpower said: PS In what part of SA are you located? Sinoville - Pretoria Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 (edited) Ok so here is a bit more info on the system installed. 1. Axpert King 5Kw - 48V - 80A MPPT Regulator 2. 8 x Narada 200ah 12V - model 12NDF200 3. 12 x Renewsys 270w panels Edited August 27, 2019 by lordnoob Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 27, 2019 Share Posted August 27, 2019 If you want to maximise PV you need to get another MPPT charge controller and separate the two arrays. The MPPT is trying to maximise the solar production by changing the charge voltage. If you have two different PV arrays, the MPPT won't be able to find the maximum power point and the charging will be sub optimal. lordnoob 1 Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 27, 2019 Share Posted August 27, 2019 1 hour ago, Pietpower said: Use double the energy to heat and then cool the water for zero net effect. We need something like that to get the economy going again. Pay one bunch of people to dig holes, and the other bunch to fill them in again. I'll let the government know that the unemployment problem is solved! Quote Link to comment Share on other sites More sharing options...
___ Posted August 27, 2019 Share Posted August 27, 2019 1 hour ago, DeepBass9 said: We need something like that to get the economy going again. Pay one bunch of people to dig holes, and the other bunch to fill them in again. I'll let the government know that the unemployment problem is solved! Sounds like Germany during the war. Everyone had a job... and everyone was paid... but ultimately everything was in tatters by the end of it all. Quote Link to comment Share on other sites More sharing options...
lordnoob Posted August 27, 2019 Author Share Posted August 27, 2019 I was thinking the same thing, it is a Hybrid system Quote Link to comment Share on other sites More sharing options...
Bobster. Posted August 27, 2019 Share Posted August 27, 2019 4 hours ago, DeepBass9 said: They should ideally reach float charge state in the later afternoon where the volts will be lowered and keep the batteries topped up. They may do that but you will need to look at the battery volts graph to see if that is occurring. I'm interested in this. Most days my batteries are charged by midday, and thereafter the panels just service the load (unless it gets hell of big) until late afternoon. Is this a problem for the batteries (that's how I read your sentence) or just a case of not utilising perfectly good solar power? Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted August 27, 2019 Share Posted August 27, 2019 (edited) Not using the power is the problem, it is essentially going to waste. There was some discussion a while ago about the best way to use it, and mining bitcoin or pumping water were probably the only useful suggestions. Its not a problem for the batteries as the MPPT will reduce the current as the batteries get fuller and then float them once they are full. As Piet said, its a balancing act to rearrange your loads so they they run when the solar power is there, so timers and smart switches can help. Edited August 27, 2019 by DeepBass9 Quote Link to comment Share on other sites More sharing options...
PaBz0r Posted August 27, 2019 Share Posted August 27, 2019 I also don't have much running in the afternoon, perhaps if somebody has used some hot water it will kick in for max 60 minutes. Thinking of getting some aircons and a pool to fill my afternoon up.. Quote Link to comment Share on other sites More sharing options...
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