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Using measured horizontal irradiation as input for PV production

Dear all, I am trying to make a comparison between the measured electrical power obtained for a PV field with the same quantity obtained for the PV field modeled into EnergyPlus. Of course, I don't want to use the default weather file for my location, since I have a set of measures for the horizontal surface taken with a pyranometer. The PV modules are installed almost in horizontal, so the total energy that they receive should be reasonably close to the one measured with the pyranometer.

I was thinking of just changing the weather file values for total solar irradiance, using elements. Then I have read on the Energy Reference that e+ uses the "Revised clear sky" model as the reference model for the sky when dealing with PV objects (Simple, One Diode or Sandia). I am not sure that it is just reading the input data from the weather file or if it instead calculates the solar irradiance based on the sky model. Also, from an early comparison between measured PV production and software simulation, the simulated values appear to be slightly lower during winter and slightly higher during summer, with respect to the measured values, and it is not clear what is the reason for that difference.

Thanks FS

Using measured horizontal irradiation as input for PV production

Dear all, I am trying to make a comparison between the measured electrical power obtained for a PV field with the same quantity obtained for the PV field modeled into EnergyPlus. Of course, I don't want to use the default weather file for my location, since I have a set of measures for the horizontal surface taken with a pyranometer. The PV modules are installed almost in horizontal, so the total energy that they receive should be reasonably close to the one measured with the pyranometer.

I was thinking of just changing the weather file values for total solar irradiance, using elements. Then I have read on the Energy Reference that e+ uses the "Revised clear sky" model as the reference model for the sky when dealing with PV objects (Simple, One Diode or Sandia). I am not sure that it is just reading the input data from the weather file or if it instead calculates the solar irradiance based on the sky model. Also, from an early comparison between measured PV production and software simulation, the simulated values appear to be slightly lower during winter and slightly higher during summer, with respect to the measured values, and it is not clear what is the reason for that difference.

Thanks FS

Using measured horizontal irradiation as input for PV production

Dear all, I am trying to make a comparison between the measured electrical power obtained for a PV field with the same quantity obtained for the PV field modeled into EnergyPlus. Of course, I don't want to use the default weather file for my location, since I have a set of measures for the horizontal surface taken with a pyranometer. The PV modules are installed almost in horizontal, so the total energy that they receive should be reasonably close to the one measured with the pyranometer.

I was thinking of just changing the weather file values for total solar irradiance, using elements. Then I have read on the Energy Reference that e+ uses the "Revised clear sky" model as the reference model for the sky when dealing with PV objects (Simple, One Diode or Sandia). I am not sure that it is just reading the input data from the weather file or if it instead calculates the solar irradiance based on the sky model. Also, from an early comparison between measured PV production and software simulation, the simulated values appear to be slightly lower during winter and slightly higher during summer, with respect to the measured values, and it is not clear what is the reason for that difference.

Thanks FS