pvlib.pvsystem.pvwatts_dc

pvlib.pvsystem.pvwatts_dc(g_poa_effective, temp_cell, pdc0, gamma_pdc, temp_ref=25.0)[source]

Implements NREL’s PVWatts DC power model [1]:

\[P_{dc} = \frac{G_{poa eff}}{1000} P_{dc0} ( 1 + \gamma_{pdc} (T_{cell} - T_{ref}))\]

Note that the pdc0 is also used as a symbol in pvwatts_ac(). pdc0 in this function refers to the DC power of the modules at reference conditions. pdc0 in pvwatts_ac() refers to the DC power input limit of the inverter.

Parameters:
  • g_poa_effective (numeric) – Irradiance transmitted to the PV cells in units of W/m**2. To be fully consistent with PVWatts, the user must have already applied angle of incidence losses, but not soiling, spectral, etc.
  • temp_cell (numeric) – Cell temperature in degrees C.
  • pdc0 (numeric) – Power of the modules at 1000 W/m2 and cell reference temperature.
  • gamma_pdc (numeric) – The temperature coefficient in units of 1/C. Typically -0.002 to -0.005 per degree C.
  • temp_ref (numeric, default 25.0) – Cell reference temperature. PVWatts defines it to be 25 C and is included here for flexibility.
Returns:

pdc (numeric) – DC power.

References

[1]A. P. Dobos, “PVWatts Version 5 Manual” http://pvwatts.nrel.gov/downloads/pvwattsv5.pdf (2014).