Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
1

PhotovoltaicPerformance:EquivalentOneDiode Severe Error

asked 2025-07-16 06:49:31 -0500

Tim's avatar

updated 2025-07-21 10:09:11 -0500

I am trying to run panels described in the California Energy Comission Database https://www.energy.ca.gov/media/2367 Most panels produce a fatal crash in EnergyPlus using the OneDiode model. I am using EnergyPlus Version 23.1.0-87ed9199d4

* Severe * EquivalentOneDiode Photovoltaic model failed to find maximum power point * ~~~ * Numerical solver failed trying to take exponential of too large a number
* ~~~ * Check input data in PhotovoltaicPerformance:EquivalentOne-Diode * ~~~ * VV (voltage) = 17.15636 * ~~~ * II (current) = -3335.62140 * Fatal * FUN: EnergyPlus terminates because of numerical problem in EquivalentOne-Diode PV model
...Summary of Errors that led to program termination: ..... Reference severe error count=1

Is this model not maintained anymore? It seems unusable with more modern panels unless I am missing something.

Here are two panel descriptions -> Panel0 works, Panel1 causes the crash.

PhotovoltaicPerformance:EquivalentOne-Diode,
  Panel0PhotovoltaicPerformance, ! Name
  CrystallineSilicon, ! cell Type
  60, ! cells in series
  1, ! module area [m2]
  0.9, ! tau alpha product
  1.12, ! electron bandgap [eV]
  1000000, ! shunt resistance [ohms]
  9.34, ! short circuit current [A]
  38.63, ! open circuit voltage [V]
  25, ! reference temperature [C]
  1000, ! reference radiation [W/m2]
  2.24, ! current at max power
  29.84, ! voltage at max power
  0.052, ! dIsc/dT
  -0.313, ! dVoc/dT
  20, ! NOCT ambient temp [C]
  47.4, ! NOCT cell temp [C]
  800, ! NOCT radiation [W/m2]
  30, ! heat loss coeff [W/m2-K]
  50000; ! heat capacity [J/K]


PhotovoltaicPerformance:EquivalentOne-Diode,
  Panel1PhotovoltaicPerformance, ! Name
  CrystallineSilicon, ! cell Type
  72, ! cells in series
  2.14, ! module area [m2]
  0.9, ! tau alpha product
  1.12, ! electron bandgap [eV]
  1000000, ! shunt resistance [ohms]
  11.36, ! short circuit current [A]
  49.1, ! open circuit voltage [V]
  25, ! reference temperature [C]
  1000, ! reference radiation [W/m2]
  10.67, ! current at max power
  40.8, ! voltage at max power
  0.062, ! dIsc/dT
  -0.313, ! dVoc/dT
  20, ! NOCT ambient temp [C]
  45.4, ! NOCT cell temp [C]
  800, ! NOCT radiation [W/m2]
  30, ! heat loss coeff [W/m2-K]
  50000; ! heat capacity [J/K]
edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted
3

answered 2025-07-16 20:29:26 -0500

Greg Estep's avatar

updated 2025-07-16 20:50:33 -0500

Hi Tim, I find it pretty easy to make a mistake entering the data from cut sheets into the E+ object. Particularly the temperature coefficient of short circuit current and open circuit voltage. Sometimes the cut sheets are in units of % and E+ units are not. I would double check these inputs. I opened the spreadsheet and it looks like the values for the temperature coefficients are in %. You need to multiple the short circuit current (and open circuit voltage) by the coefficient value, then divide by 100.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Training Workshops

Question Tools

1 follower

Stats

Asked: 2025-07-16 06:49:31 -0500

Seen: 129 times

Last updated: Jul 16