developer_mh

Hi Tim, we just discussed it here. We think you should go and try modelling the house in sketchup and then import it in PV*SOL. Even if you have to learn to use sketchup first, you will be faster in the long run. Modelling these types of buildings in PV*SOL with polygons will be very tricky. One of our 3D team members modelled this house in 20min. He used sketchup a lot, so perhaps you will need more time for your first models, but in the end you can really save a lot of time when you have a lot of those complex buildings. Kind regards, Martin

Hello Ragy, I would recommend to use the software (e.g. PV*SOL) to simulate the MPP voltage for a given temperature. In my opinion it is not possible to calculate it with easy formulas. If only the temperature coefficient (tc) of Voc and Pmpp are given on the data sheet, there is no way (known to me) to derive from those numbers the tc of Vmpp, except by simulating. As to your options/questions: I'd guess that the tc of Pmpp (Pmax) (in %) is always closer to the tc of Vmpp than to the tc of Voc. So, if you can't simulate, choose the tc of Pmpp. But really, in the end it is those questions why we need simulation tools in order to plan our PV systems correctly. If you want to calculate in your head, then this is ok, but be aware that the results will not be reliable. We do not recommend any other method to determine the voltage ranges of PV systems other than simulating. Kind regards, Martin

Hi Ricardo, thank you for the project files. The differences are induced by an update of the PV module data by Longi. The newer module data are taken for simulation once you enter the 3D environment. The reflection behaviour of the modules is now different which is why the simulation results are deviating slightly. That is, when I do the following, I get identical results for the inverter groups: Load the project where the whole plant with all inverters is defined Go into 3D environment, return and adopt the data Simulate Save results, e.g. for Inverter 1 Then re-enter 3D environment Delete all configurations except configuration 1 Return to main program and adopt the data Simulate See the results for Inverter 1 are the same as from step 4 Hope that helps, kind regards, Martin

Hello Infinitech, very good question, and an important one! It is unfortunately a common mistake, even among experts in the community, to mix up the temperature coefficients of the open circuit and MPP voltage. These are not the same! The LR6-60 HPH 320M module in our database has a temperature coefficient for the open circuit voltage of -116.97 mV/K, or 0.286 %/K. So the Voc at 70°C will be Voc(70°C) = Voc(25°C) + 45 K * (-0.117 V/K) = 40,9 V - 5.265 V = 35.64 V The temperature coefficient of the MPP voltage will be different, however, usually higher than for Voc. You can easily see that the temperature coefficient of the MPP voltage must be higher than the one of Voc by looking at the temperature coefficient of the power, which is -0.37 %/K. So there must be additional, temperature related losses to close the gap between -0.37 % and -0.286 %. This is why we have to simulate the module at the given temperatures we want to analyse. We take the three temperature coefficients of Voc, Isc and Pmpp and simulate the module characteristics at a given temperature, e.g. 70°C. From these curves we can detect MPP voltage and current. See here the diagram of the power over voltage for different temperatures for the LR6-60 HPH 320M module. Voc(70°C) is around 35V, as expected. The MPP voltage seems to be at 27.5 V, which relates to a relative loss of -0.425 %/K. This is where the 551 V come from, 20 * 27.5 V ≈ 551 V. The other way 'round, you can easily check that an Vmpp of 590.74 V (as stated by Fronius) must be too high to meet the condition of the temperature coefficient of the power. Simple check: Vmpp(70°C) = 590.74 V, Impp(70°C) = 9.69 A, so the Pmpp(70°C) would be 590.74 V * 9.69 A = 5722 W. This would be a relative change of -0.233 %/K of the power, so far too less. The datasheet says -0.37 %/K. Hope that clarifies the matter. If you have any question on the topic, please don't hesitate to ask. In the meanwhile, we will contact Fronius to point them out to this problem as well. Kind regards, Martin

Hi S.A.Basit, the usage of the cable plan in 3D is documented here: http://3d-help.valentin-software.com/pvsol/en/#t=html%2Fen%2F3d%2FEinfuehrung_in_den_Kabelplan.htm If you need further information, please don't hesitate to ask. Kind regards, Martin

Hi Ricardo, this is an interesting case! Could you please provide the project files (the big one and the three small ones), so that I can have a look what is happening there? You can either send them here directly or by private message. Thanks a lot, Martin

yes, R7. But right now we don't have a release schedule for that, sorry. Kind regards, Martin

Hi Ries, there was indeed an error in summing up the areas of the module surfaces that are connected to one inverter. Thank you for calling our attention to that. It happens in cases when not all modules from one module area are connected to one inverter. Actually a case that occurs not so seldomly, and it was correct in versions before 2019 R1, but we refactored parts of our code base where this bug came in. Again, thank you for finding this. We will release a bug fix in the next bugfix release - but not in the upcoming R6, since this is already on the way. Kind regards, Martin

Hi Tim, thanks for the question. Right now there is no option for wind turbines, but we will add it to our list of feature requests. Thanks and kind regards, Martin

Hello Hayder Ali, thank you for your question. I am afraid that this is not possible at the moment. But we will put it on the list of feature requests. Kind regards, Martin

Hi Magnus, yes, I will forward this request to our database team so that they can contact Ja Solar in order to have their newest products inserted into our database. If you want, you can also contact the manufacturer directly (as they are responsible to update the database entries) or send a notification to our database team at database@valentin-software.com Kind regards, Martin

Hi Ries, could you provide a project file, please? This would make it easier for us to see what is going on there. You can either post it here directly or send it to me via private message. Thanks a lot in advance, Martin

Hi Jack, if the desired inverter is not in our database (which is filled by the manufacturers), you have two options: Enter the inverter yourself Contact the manufacturer to enter their inverter Ideally, you could do both, so that you can start planning your PV system with the inverter right away and you have the manufacturer notified of the missing entry. The easiest way to enter the SE50K manually is to create a copy of the SE33.3K and change the values according to the datasheet (https://www.solaredge.com/sites/default/files/se_commercial_three_phase_inverters.pdf) I will inform our database team so that they as well can contact SolarEdge to have the new products entered. Thanks and kind regards, Martin

Hi Tim, if you combine SolarEdge (SE) power optimizers with non-SE inverters, one difference will be the DC voltage range. SE inverters usually have a fixed DC voltage, other inverters have a rather wide range of several hundreds of volts where they can track the IV curves and find the maximum power point (MPP). The output will be slightly different, yes. The best way to find out these differences is just to simulate different systems and compare the results Kind regards, Martin

Hi Kristian, I am afraid that this is not possible at the moment. Right now the starting SOC of the batteries in stand alone (offgrid) systems is determined by the average SOC that is roughly to be expected during operation. For that we take the SOC control parameters of the diesel generator: Considering the time and the SOC thresholds we determine an "average" SOC that is used as a starting point. This behaviour was desired by the SMA engineers to avoid untypical system behaviour in the beginning of the simulation (the offgrid simulation part of PV*SOL was design for SMA in the first place, some years ago). But we will put this feature request on our list, thank you. Kind regards, Martin

Hi Low Carbon Exchange, thank you for your feedback! We will look into that for the next release. Kind regards, Martin

Thanks for the project. For me, this looks fine. The nominal output current of the Enphase inverter is max. 1.5 A (350 W / 230 V), usually it will be far less since you only have the 320 Wp from the module when the irradiance is at 1000 W/m². But even if you have 1.5 A output from the inverter, your ohmic power loss is only about 0.4 W (P = I² x R). The resistance of your cable is 0.18 Ω ( ρ*l/A, 0.018 Ω·mm²/m * 25m / 2.5mm²). So the relative losses on the AC side in your worst case are 0.4 W / 350 W = 0.12 %. In the DC side, you have 9.6 A MPP current (under STC, like above) and a cable resistance of 0.018 Ω·mm²/m * 2m / 4mm² = 0.009 Ω, so a power loss of 0.83 W (or relative 0.83/320 = 0.36%). So, when comparing ohmic losses, be sure to always have an eye on the currents. Cheers, Martin

Hi Sander, could you provide us with a project file so that we can investigate your test case better? You can either post it here or send it over by private message. Thanks a lot, Martin

Hi Sander, thank you for the post, it is interesting to see that Huawei now also provides power optimizers. From the datasheet and their website it is not clear, however, in which optimizer mode they really operate. See an explanation on the operation modes here: https://help.valentin-software.com/pvsol/2019/calculation/power-optimizer/ To include them into our database, we have to make sure we get the optimizing mode right. I will inform our database team so that they can contact Huawei to ask for more information. In the meanhwile you could either ask them directly or you could just enter the device as a SolarEdge device (full mode), if you want to accept the risk of choosing the wrong optimizing method. Kind regards, Martin

Hallo Sepp, ich habe das gerade hier nachvollzogen und kann es leider nicht nachstellen. Das heißt, bei mir ist das Logo auch auf anderen Rechnern als meinem zu sehen. Welche Version von PV*SOL benutzt du denn? Ist das Logo evtl schreibgeschützt oder in einem geschützten Bereich (Netzlaufwerk oä?). Evtl. könnte Abhilfe schaffen, das Logo zuerst auf den Rechner zu kopieren, auf dem auch PV*SOL installiert ist und es dann in den Benutzer-Optionen neu auszuwählen. Über eine kurze Rückmeldung, ob das geholfen hat, würden wir uns sehr freuen. Viele Grüße, Martin

Hi João, No, sorry. But you could simulate the 3D environment without tracking, save the shading losses from the results and enter them as a shading percentage of your 2D simulation with tracking system. This will only cover the shading by far objects (homogeneous shading), however. A detailed shading analysis with mutual shading of the trackers for example, is not possible. But if the tracking systems have sufficient distance from each other, this won't be problematic. Hope that helps, kind regards, Martin

Hi Tim, thank you for the interesting question. I guess it is neither a real issue nor a limitation of our software If you select SolarEdge power optimizers with inverters of different manufacturers you will get a "warning" from PV*SOL, stating that the optimizers may only be used with inverters from SolarEdge. This is because SolarEdge says so (not sure why), but since it is only a warning in PV*SOL, you can simulate the system anyway. We heard from other planners that they combine SE power optimizers with other inverters as well. But perhaps check again with SolarEdge what their opinion is on that topic. Kind regards, Martin

Hi matko89, please only write one post per issue, thank you. This will keep things easier to follow up for you and for us as well. Did you get positive feedback on the deactivation form? If yes and the problem persists, please contact our technical hotline at hotline@valentin-software.com. Kind regards, Martin

Hi matko89, did you get positive feedback on the deactivation form? If yes and the problem persists, please contact our technical hotline at hotline@valentin-software.com. Kind regards, Martin

Hi João, could you provide us with the project files so that we can analyse the comparison? Without seeing the PV system and the meteo data it is impossible to tell where the difference in PR and yield comes from. Thanks a lot in advance and kind regards, Martin