Cassie Posted September 16, 2020 Posted September 16, 2020 How many watts should 12x 370W MONO panels with full sun, at 12:00 more or less deliver? I'm getting only 500w, that surely can't be correct? Quote
Louisvdw Posted September 16, 2020 Posted September 16, 2020 You should get closer to 3200W, so 500W is very far off. How are the panels connected and what MPPT are you using? Quote
PaulinNorthcliff Posted September 16, 2020 Posted September 16, 2020 Are they connected in series or in parallel? Quote
fredhen Posted September 16, 2020 Posted September 16, 2020 An additional point is also that what is generated needs somewhere to go. Do you have any loads on at that time / have batteries charging / allow feedback to the grid? Otherwise it may be possible that it's only generating what is required. Quote
Cassie Posted September 16, 2020 Author Posted September 16, 2020 5 minutes ago, Louisvdw said: You should get closer to 3200W, so 500W is very far off. How are the panels connected and what MPPT are you using? It's the Kodak VMiii Axpert 48v 450v MPPT. Panels are 6 is serie, 2 strings. Quote
Cassie Posted September 16, 2020 Author Posted September 16, 2020 8 minutes ago, PaulinNorthcliff said: Are they connected in series or in parallel? 6 in series and 2 parallel strings Quote
Cassie Posted September 16, 2020 Author Posted September 16, 2020 7 minutes ago, fredhen said: An additional point is also that what is generated needs somewhere to go. Do you have any loads on at that time / have batteries charging / allow feedback to the grid? Otherwise it may be possible that it's only generating what is required. Not grid-tied. Well the installation was just completed and an additional Pylontech US3000 was added, so maybe it is the charging of the batteries - can that be the case? This measurement is from what can be seen on the inverter at a specific moment - not a kWh reading. Quote
Bloubul7 Posted September 16, 2020 Posted September 16, 2020 The panels will only deliver up to the connected load at the given point in time. The solar production will vary based on the following: Battery SoC (state of charge) Current load Inverter mode You should roughly be getting 80% of rated power at peak. Quote
DeepBass9 Posted September 16, 2020 Posted September 16, 2020 Switch on a few big loads t midday and see what solar production you get, it can be you have few loads and your batteries are charged, so as pointed out above, there is nothing for the power to do. Quote
Bobster. Posted September 16, 2020 Posted September 16, 2020 I have 12 x 325 w panels. In my case 6 face north(ish) and 6 face east(ish). My peak power comes at about 11:30 and there can be 3.2 kw coming off the roof (that's the highest number I've actually notedI might get a bigger number if I watch the power curves all day, every day) But this depends on the weather and, as others have noted, on the demand. If my batteries are fully charged and the house is just ticking over then there is no point in pulling 3KW off the roof (unless I feed back into the grid, and this doesn't make financial sense for me), and the system derates the panels and draws just what it needs. So you can't draw conclusions from a snap shot of your system at a single point in time. Boerseun 1 Quote
Gelo Posted September 16, 2020 Posted September 16, 2020 No no no no..... your panels are definitely suffering from that underperformance bug I read about that was part of a bad batch. Start taking them off load them up (I will supply bakkie) forget the supplier/installer hes full of balls anyway. Come help me install on my roof and proper test for around 15 to 20 years I will give a proper diagnosis by then. Jokes aside you can have 40kw on the roof and if your load is 10watts thats what you will be supplied from Pv. As the guys stated give the panels work to do it give them a load to work with put on appliances during the day to test it out. My setup 8x 390 monos on the roof and 2x 2.4 lithiums, fully charged by 8:45. House tinkers away pulling 120watts or maybe even 460watts occasionally when fridges turn on and. Gave the panels light work with pool pump 0.75kw and even that is light work for 3kw which is not much at 900watts through out the day. Basically your system will only give what your load requires no more, think supply and demand the more your load demands the more the pv will supply. Put it to the test and switch on all the silly appliances you can find once your batteries are fully charged and then have a look at pv performance. Boerseun 1 Quote
Boerseun Posted September 19, 2020 Posted September 19, 2020 Axpert based inverters can only service a load...connected to the output of the inverter...so if your batteries are full then the inverter will only draw the ammount of solar power needed to supply the load at the time..so if your load is only 500 watt then that is what the axpert inverter will draw from the solar array... if you had a Luxpower hybrid, Goodwe hybrid, Kodak hybrid or a Sunsynk hybrid then the solar array would be able to provide power to Essential and Non Essential loads like geysers aircons washing machines dishwashers etc..without drawing power from the batteries and only if the Sun is shining. Also if your municipality allows it you will be able push excess power back into the grid and if that is the case your array would run at maximum production. Gelo 1 Quote
Gerrie Posted September 24, 2020 Posted September 24, 2020 On 2020/09/19 at 12:00 PM, Boerseun said: if your load is only 500 watt then that is what the axpert inverter will draw from the solar array... if you had a Luxpower hybrid, Goodwe hybrid, Kodak hybrid or a Sunsynk hybrid then the solar array would be able to provide power to Essential and Non Essential loads like geysers aircons washing machines dishwashers etc..without drawing power from the batteries and only if the Sun is shining. Do these hybrid inverters need Eskom supply to function like above or do they also function like this when Eskom is turned off. My knowledge on these hybrid inverters are basically zero. Quote
jykenmynie Posted September 24, 2020 Posted September 24, 2020 3 minutes ago, Gerrie said: Do these hybrid inverters need Eskom supply to function like above or do they also function like this when Eskom is turned off. My knowledge on these hybrid inverters are basically zero. Obviously Victron’s MP and Quattro inverters are also “hybrid”. Yes, when appliances that are directly connected to the grid requires power, they would create a demand for it, which something like an energy meter reports to the inverter. The hybrid then knows how much power it can essentially send upstream to try and “zero” the energy meter. This is obviously great for fully utilising all the PV you have, but not going through the expensive of purchasing 15kVA worth of inverters to run your entire house through, unless you actually need to be off-grid, then a hybrid won’t help. It does require you to think just a little more about sizing and managing your battery bank, because the inverter would try to zero the energy meter with batteries as well as PV. It would still stop discharging the batteries at a minimum SoC level (unless there is loadshedding, when it’ll take it deeper to keep the critical loads alive). So turning on your oven when there isn’t enough PV would attempt to take the power from the grid, which it will at first, but then the inverter would pick it up from the battery bank. Obviously the inverter still has a hard limit on inverting capacity, so if you have 10kW of PV available and 10kW of demand, and the batteries are full, it’ll still only take 5kW and invert it to AC (getting say 4.5kW AC). The rest would still go to waste. This situation is typically not possible anyways, because the built-in MPPTs of most inverters aren’t big enough. With a Victron though, you can add what you want on the DC side and therefore create “excess” PV if you need it for a cloudy day, for example, because the entire system is modular. Essentially, a true “hybrid” is able to bled power sources and push back to the grid (either only to the rest of your house or beyond, depending on settings). It doesn’t need all its power from one source at a time (like PV only, battery only or grid only) and can utilise excess PV much better. You can run your geysers and washing room from PV during the day, for example, even though they are not on your backup circuit. fredhen and Gerrie 2 Quote
Boerseun Posted September 24, 2020 Posted September 24, 2020 32 minutes ago, Gerrie said: Do these hybrid inverters need Eskom supply to function like above or do they also function like this when Eskom is turned off. My knowledge on these hybrid inverters are basically zero. A True Hybrid Inverter like the 5 kw Sunsynk or Deye inverter has Different modes it can function in. As an example say you start with the Inverter and Panels only then the Sunsynk inverter functions like a Grid tied inverter which means when eskom is on and as an example you have a 6.5 KW Solar array and on the roof all your ac loads that you have will be supplimented by the 6.5KW solar array any excess power produced will be pushed back into the grid however these inverters come with a CT clamp that must be connected where the utility supply comes in with this the inverter can controll how much you feed back to the grid you have full controll over that. So essentially the 5.5 KW inverter is a 6.5 KW Grid tied inverter in that respect. If eskom power goes off the Grid tied output of the inverter switches off and comes back on if eskom come back on. But now let us say you add a battery bank and you have loads that you need to run off the battery bank during loadshedding when eskom is off then the 5.5KW off grid part of the inverter comes into play and the limit of the maximum battery powered load of the inverter is 5.5 KW typically we call these loads essential loads. So in this scenario the inverter will always provide power to these loads regardless of the source be it battery solar or utility power the inverter also has an internal charger that will and can charge the batteries if solar power is not available however you can controll this feature. Let say you have an essential load of 500 Watt and your solar array is producing 6500 watt then 6000 watt will be available for non essential loads like geysers aircons pool pumps heat pumps ovens etc and lets say the load is 8000 watt the inverter will supply 6000 watt of the 8000 watt and allow 2000 watt to flow in from eskom to supply the load so that means there is no limit to the load on the the non essential side of the inverter but there is a 5.5 KW limit on the loads on the essential load side of the inverter. So basically The Sunsynk 5.5 KW inverter is a 6.5KW grid tied inverter combined with a 5.5KW off grid inverter all in one. Gerrie 1 Quote
jykenmynie Posted September 25, 2020 Posted September 25, 2020 On 2020/09/24 at 8:27 AM, Boerseun said: that means there is no limit to the load on the the non essential side of the inverter but there is a 5.5 KW limit on the loads on the essential load side of the inverter. Note that not all hybrids have this limit. Victron MP 5kVA can transfer up to 50A and invert another 20A on its outputs. So while Eskom is up, you don’t need to worry about overloading the output of the inverter as you have at a minimum 11.5kW available, and if you have spare PV, up to another 4.5kW (assuming DC to AC conversion loss). This is quite an important feature for me, because I didn’t want to be limited on my essential circuits (which includes all the plugs, even those that would have heaters on in winter) while the grid is available. I think some other hybrids do go up to 40A though, which should be enough. Quote
Boerseun Posted September 26, 2020 Posted September 26, 2020 20 hours ago, jykenmynie said: Note that not all hybrids have this limit. Victron MP 5kVA can transfer up to 50A and invert another 20A on its outputs. So while Eskom is up, you don’t need to worry about overloading the output of the inverter as you have at a minimum 11.5kW available, and if you have spare PV, up to another 4.5kW (assuming DC to AC conversion loss). This is quite an important feature for me, because I didn’t want to be limited on my essential circuits (which includes all the plugs, even those that would have heaters on in winter) while the grid is available. I think some other hybrids do go up to 40A though, which should be enough. Yes that is correct however the explenation is just to give a basic Idea SMA also offers similar tech to Victron but what you say is 100% Quote
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