Adds k parameter to temperature.ross

docs/sphinx/source/whatsnew/v0.13.1.rst

@@ -19,8 +19,11 @@ Bug fixes
 
 Enhancements
 ~~~~~~~~~~~~
-
-
+* Rename parameter name ``aparent_azimuth`` to ``solar_azimuth`` in :py:func:`~pvlib.tracking.singleaxis`.
+  (:issue:`2479`, :pull:`2480`)
+* Add k coefficient in :py:func:`~pvlib.temperature.ross`
+  (:issue:`2506`, :pull:`2521`)
+
 Documentation
 ~~~~~~~~~~~~~
 * Substantiate definitions of solar/surface azimuth/zenith and aoi on the
@@ -48,4 +51,5 @@ Contributors
 ~~~~~~~~~~~~
 * Elijah Passmore (:ghuser:`eljpsm`)
 * Rajiv Daxini (:ghuser:`RDaxini`)
-* Omar Bahamida (:ghuser:`OmarBahamida`)
+* Omar Bahamida (:ghuser:`OmarBahamida`)
+* Rodrigo Amaro e Silva (:ghuser:`ramaroesilva`)

pvlib/temperature.py

@@ -618,7 +618,7 @@ def faiman_rad(poa_global, temp_air, wind_speed=1.0, ir_down=None,
     return temp_air + temp_difference
 
 
-def ross(poa_global, temp_air, noct):
+def ross(poa_global, temp_air, noct=None, k=None):
     r'''
     Calculate cell temperature using the Ross model.
 
@@ -638,6 +638,9 @@ def ross(poa_global, temp_air, noct):
     noct : numeric
         Nominal operating cell temperature [C], determined at conditions of
         800 W/m^2 irradiance, 20 C ambient air temperature and 1 m/s wind.
+    k: numeric
+        Ross coefficient [Km^2/W], which is an alternative to employing
+        NOCT in Ross's equation.
 
     Returns
     -------
@@ -650,19 +653,52 @@ def ross(poa_global, temp_air, noct):
 
     .. math::
 
-        T_{C} = T_{a} + \frac{NOCT - 20}{80} S
+        T_{C} = T_{a} + \frac{NOCT - 20}{80} S = T_{a} + k × S
 
     where :math:`S` is the plane of array irradiance in :math:`mW/{cm}^2`.
     This function expects irradiance in :math:`W/m^2`.
 
+    Representative values for k are provided in [2]_, covering different types
+    of mounting and module structure.
+
+    +---------------------+-----------+
+    | Mounting            | :math:`k` |
+    +=====================+===========+
+    | Well cooled         | 0.02      |
+    +---------------------+-----------+
+    | Free standing       | 0.0208    |
+    +---------------------+-----------+
+    | Flat on roof        | 0.026     |
+    +---------------------+-----------+
+    | Not so well cooled  | 0.0342    |
+    +---------------------+-----------+
+    | Transparent pv      | 0.0455    |
+    +---------------------+-----------+
+    | Facade integrated   | 0.0538    |
+    +---------------------+-----------+
+    | On sloped roof      | 0.0563    |
+    +---------------------+-----------+
+
     References
     ----------
     .. [1] Ross, R. G. Jr., (1981). "Design Techniques for Flat-Plate
        Photovoltaic Arrays". 15th IEEE Photovoltaic Specialist Conference,
        Orlando, FL.
+    .. [2] E. Skoplaki and J. A. Palyvos, “Operating temperature of
+       photovoltaic modules: A survey of pertinent correlations,” Renewable
+       Energy, vol. 34, no. 1, pp. 23–29, Jan. 2009,
+       :doi:`10.1016/j.renene.2008.04.009`
     '''
-    # factor of 0.1 converts irradiance from W/m2 to mW/cm2
-    return temp_air + (noct - 20.) / 80. * poa_global * 0.1
+    if (noct is None) & (k is None):
+        raise ValueError("Either noct or k need is required.")
+    elif (noct is not None) & (k is not None):
+        raise ValueError("Provide only one of noct or k, not both.")
+    elif k is None:
+        # factor of 0.1 converts irradiance from W/m2 to mW/cm2
+        return temp_air + (noct - 20.) / 80. * poa_global * 0.1
+    elif noct is None:
+        # k assumes irradiance in W.m-2, dismissing 0.1 factor
+        return temp_air + k * poa_global
 
 
 def _fuentes_hconv(tave, windmod, tinoct, temp_delta, xlen, tilt,