Linda Thoren
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Posts posted by Linda Thoren
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Hello,
Defining a bifacial system with a 3D scene comes with certain constraints, ensuring the regularity of the arrangements of tables for the bifacial 2D model computation. You can read more about the 2D model conditions in the following help page:
https://www.pvsyst.com/help/bifacial-conditions.htmThe threshold for regular pitch can be modified in the advanced parameters, by changing the value "Pitch RMS limit for bifacial 2D models"
Kind regards
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Hello,
In PVsyst it is possible to define an hourly self-consumption profile and in the economic evaluation you can also define precise tariffs for electricity sale as well as calculating the gain from self-consuming compared to grid consumption. I link 2 video tutorials below.
A large enough system will fulfill the energy need by day, as well as injecting the excess energy into the grid. For example, below you see the loss diagram for the DEMO Residential system at Geneva variant VC4 : The result is divided in to user from grid, to user from solar and to grid.
You can also include a battery storage solution to increase the self-consumption, though it is not yet possible to inject energy stored in the batteries to the grid (unless you use the peak shaving strategy, that can not be combined with a self-consumption profile)
In the Advanced Simulation window, you can then create an Output file with all the relevant parameters for your project in Daily or Hourly timesteps.
I hope this helps to get started with your Net billing project,
Kind regards
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Hello,
It is not possible to have multiple orientations on the same string. If you have two or more strings, it is possible to put two orientations on the same MPPT input by using the Mix orientation 1 and 2 option (you might have to change the order of the orientation since it in this version of PVsyst is only possible to mix orientation 1 and 2).
Kind regards
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You have chosen a 7.0 kW inverter, and panels with a nominal power of 5.0kW, thus the inverter is a bit oversized. With an orange warning you can still run the simulation.
Please look at the following video tutorial for more information about the sizing:
Kind regards
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Thank you for your suggestion. This might be developed in a future version, though it is not yet on our roadmap and will not be available any time soon.
In our experience, this strategy corresponds well to what users expect from a battery storage solution for increased self-consumption, to charge when excess solar power is available during the day, and discharge as soon as the user needs power - which normally is during the night.Kind regards
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Dear Rosana,
Indeed, by using the Self consumption strategy, the batteries will charge when excess solar power is available and discharge as soon as the user needs power. It is not possible to define specific hours for charging/discharging.
Kind regards
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Dear Loïs Masson,
Indeed the panels included in the database has gone through a certain level of control. But implemented in the software is also warning messages and information concerning in particular the IAM curve and low light efficiency. If you open a PAN file, you typically will have this kind of message encouraging you to have a look at the IAM curve.
In the Additional Data, Custimized IAM you can modify an over evaluated IAM curve by choosing the Default Fresnel. This manipulation can also be done through the detailed losses window, IAM Losses tab.
Below I attach a link to how the IAM profile is determined and what kind of data you possibly could ask the supplier to provide
Kind regards
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Hello,
E_User is the Energy supplied to the user and correspond to the load-profile that you have defined. E_Solar correspond to your self consumption, i.e. the energy to the user from your solar installation. EFrGrid is the energy from the grid needed to fulfill the user's load-profile, the E_User. So in this case E_User = E_Solar + EfrGrid, and it seems to be accurate in your results.
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Dear Oussama Belarbi,
Thank you for bringing this to our attention. It appears that this issue is a bug introduced in the current version. The issue is reported and we will work to resolve it in a future version. In the meantime, you can either revert to a previous version or create an hourly load profile as a CSV file and instead use the Load values from a CSV hourly/daily file option
Kind regards
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For the dimensioning in the system window, PVsyst show graphs based on the values defined in the project settings e.g. -10°C by default for the Lower temperature for Absolute Voltage limit, not from the local site temperature data. This value is supposed to represent the lower value ever measured at the site and this value will not impact the simulation and works only as a guide for the dimensioning of the system. The simulation will be done with the temperatures from the weather file of your site.
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The dimensioning messages are based on the data and limitations in the panel and inverter file and the main electrical characteristics are calculated under chosen operation conditions using the one-diode-model. Verify that the temperature coefficient under the Model parameters in the panel file is correct, see the following help page regarding the temperature coefficients:
https://www.pvsyst.com/help/pvmodule_tempcoefficients.htm
https://www.pvsyst.com/help/pvmodule_corrtemper.htmThe limit of Voc at -10 degrees is set in the project settings, where the threshold of -10 degrees can be changed to reflect the coldest temperature observed at the site.
You can read more about the Array voltage sizing in the following help page:
https://www.pvsyst.com/help/systemgrid_vocond.htmKind regards
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Hello,
In the current version of PVsyst it is not possible to use bifacial panels in the off-grid system.
To use bifacial panels, you should define a grid-connected system, define a self consumption profile and not allow injection to the grid when defining the battery storage. Energy injected from the grid to fulfill the energy need should be considered as missing energy if the system indeed is not connected to the grid.
It is not possible to mix bifacial and monofacial arrays in the same system, though you can create multiple variants and simulate the two different systems individually.
Kind regards
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Hello,
In the Advanced Simulation, you can create an Output File with hourly or daily values for a large number of variables, for example Global horizontal irradiation, Sun height, Sun azimuth, Global corrected for horizon/far shadings.
Kind regards
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Hello,
The inverter clipping losses, the Inverter loss over nominal power, is to large extent due to the sizing and configuration of your system.
If you have higher clipping losses than expected, it could be due to the the definition of the multi-MPPT inputs. Please read the following help pages on the subject:
https://www.pvsyst.com/help/powersharing.htm
https://www.pvsyst.com/help/multi-mppt_more-examples.htmIt could also be temperature derating, at high temperatures inverters often have a lower nominal power. You can see the temperature evaluation of the inverter in the Output parameters in the .OND file.
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Hello,
To our knowledge there is no bug in the multi-MPPT features. Large Inverter Losses over nominal inv. power could appears in the case if for instance the number of strings are not a multiple of the number of MPPT inputs or if the power sharing is not activated (with a green "active" light). Please read more about the multiple MPPT and power sharing in the following help pages:
https://www.pvsyst.com/help/powersharing.htm
https://www.pvsyst.com/help/multi-mppt_more-examples.htmIf you still have difficulties, please send your project as zip file to support@pvsyst.com and we can have a closer look at it.
Kind regards
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Hello,
Far shadings from mountains can be accounted for in the Horizon window. This tool is aimed to treat shadings of objects sufficiently far, as we can consider they act on the PV field in a global way: at a given instant, the sun is or is not visible on the field.
The following two help pages further describe the Horizon profile and how to import the horizon from the web, based on the the systems exact location
https://www.pvsyst.com/help/horizon.htm
https://www.pvsyst.com/help/horizon_import.htmI hope this answers your questions,
Kind regards
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Hello,
You have 2 orientation defined but only one string per inverter, that is why you cannot mix the orientations. So if you want to use the Mixed orientation option, increase the number of strings, click OK and then go back to system again and this option will be activated. You cannot mix the orientation in an sub-array that has only one string. If you define a sub-array with 2 strings and mix the orientations, you will have one string in each orientation (and you can erase the second sub-array). In your current system you have defined one inverter per sub-array.
An other alternative is to activate the Use multi-MPPT feature and define 1 MPPT per subarray and then activate the power-sharing. Like this you can define one sub-array in each orientation but using only one inverter.
Kind regards
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Hello,
In your system, you have defined only one string. When defining orientations only entire strings are considered. Thus the Mixed orientation option in not available unless you have at least 2 strings. If you increase the number of strings, save and go back to System, the Mixed orientation option will be available.
If you indeed mean to have only one string, you should instead make an average of the two orientations.
Kind regards
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Good day!
Normally the Mixed orientation option is there as in the previous versions. I cannot manage to reproduce the situation you are in where indeed two orientations are defined without the third option of Mixing them. Can you please send your project as a zip file to support@pvsyst.com and we can have a closer look at it.
Kind regards
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Dear Stephen,
Thank you for your question.
The peak shaving strategy cannot be combined with the self-consumption strategy, this might be something we will develop in the future but it is not yet on the road map.
For the peak shaving strategy you will define a grid limitation and energy that would be curtailed because of the limitation can instead be stored in a battery pack and injected at a different time.
In the self consumption strategy you will define your load profile and simulate how much of the production you can self-consume. With a battery storage solution you can increase the self-consumption by storing the energy produced during the day to fulfill the energy need at night, thus the energy from the battery storage will not be injected to the grid but is aimed at fulfilling the users need. With the self consumption strategy you can however still impose a grid limitation through the energy management tab.
In the following link you find a playlist with our youtube tutorials of how to define a self consumption profile and how to use the different storage strategies
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Hello,
The P50-P90 statistical estimations are based on yearly values and defining P75 for hourly values would give erratic results, thus this is not possible in PVsyst.
You can find more information about the p50-p90 estimation in the following help page:
https://www.pvsyst.com/help/p50_p90evaluations.htmKind regards
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The inverter efficiency depend on a certain extent on the DC power. In the .OND file, in the Efficiency curve tab you can see the relation between the inverter efficiency and the Power in the DC circuit. The efficiency is then calculated in hourly time steps in the simulation and monthly averages of the total production is shown in the report. The PR is also calculated in hourly timesteps and monthly and yearly averages are shown in the report.
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Dear Rajesh saha,
Your understanding is correct! At the moment the temperature and the losses due to high temperatures are not being considered at the transformer level, these are parameters we might include in future versions. So if your transformer will operate at 50°C, you should use the values for these conditions.
Kind regards
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Hello,
In the current version of PVsyst it is not possible to use multiple orientations in a standalone project, this will be possible in the coming version 8.
For now you can simulate your project as a grid connected system with multiple orientation and in the storage parameters, not allow injection to the grid. In case your result includes energy from the grid to fulfill the users need, that should be considered equivalent to missing energy in a standalone project.
Kind regards
1 MPPT with 2 string of modules
in Simulations
Posted
If the strings have the same lengths, it is sufficient to just untick the Use multi-MPPT feature and define the total number of strings to the inverter.
If the strings have different lengths indeed you you will have this constraint in the current version that you can not have empty MPPT inputs. To get around the constraints in PVsyst, you could modify the OND file to 4 MPPTs instead of 6, though by default, PVsyst assumes that an inverter with e.g. 2 MPPT inputs behaves as 2 identical inverters of half the power. You thus might have to adjust other parameters too to correspond to the use-case you are referring too. In the following help page you find more information of how PVsyst defines multi_MPPT inverters:
https://www.pvsyst.com/help/multi_mppt_use.htm