From b37211777804401c1ccfdc326ea755aea0a9caad Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Mon, 3 Nov 2025 18:03:50 -0500 Subject: [PATCH 01/11] create temperature user guide page --- docs/sphinx/source/user_guide/index.rst | 1 + .../modeling_topics/temperature.rst | 93 +++++++++++++++++++ docs/sphinx/source/whatsnew/v0.13.2.rst | 1 + 3 files changed, 95 insertions(+) create mode 100644 docs/sphinx/source/user_guide/modeling_topics/temperature.rst diff --git a/docs/sphinx/source/user_guide/index.rst b/docs/sphinx/source/user_guide/index.rst index 07102a5630..f8da3b6b44 100644 --- a/docs/sphinx/source/user_guide/index.rst +++ b/docs/sphinx/source/user_guide/index.rst @@ -26,6 +26,7 @@ This user guide is an overview and explains some of the key features of pvlib. modeling_topics/clearsky modeling_topics/weather_data modeling_topics/singlediode + modeling_topics/temperature .. toctree:: :maxdepth: 2 diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst new file mode 100644 index 0000000000..e3dc6afc28 --- /dev/null +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -0,0 +1,93 @@ +.. _temperature: + +Temperature models +================== + +pvlib provides a variety of models for predicting the operating temperature +of a PV module from irradiance and weather inputs. These models range from +simple empirical equations requiring just a few multiplications to complex +thermal balance models with numerical integration. + +Types of models +--------------- + +Temperature models predict one of two quantities: + +- *module temperature*: the temperature as measured at the back surface + of a PV module. Easy to measure, but not directly related to PV + efficiency. +- *cell temperature*: the temperature of the PV cell itself. The relevant + temperature for PV modeling, but almost never measured directly. + +Cell temperature is typically thought to be slightly higher than module +temperature. +Temperature models estimate these quantities using inputs like incident +irradiance, ambient temperature, and wind speed. Each model also takes +a set of parameter values that represent how a PV module responds to +those inputs. Different parameter values may be used for different PV +module technologies and/or the mounting conditions of the module. + +Another way to classify temperature models is whether they account for +the thermal inertia of a PV module. Temperature models are either: + +- *steady-state*: the module is assumed to have been at the specified operating + conditions for a sufficiently long time for its temperature to reach + equilibrium. +- *transient*: the module's thermal inertia is included in the model, + causing a lag in modeled temperature change following changes in the inputs. + +Other effects that temperature models may consider include variation in +photoconversion efficiency and radiative cooling. + +The temperature models currently available in pvlib are summarized in the +following table: + ++-------------------------------------------+--------+------------+--------------------------------------------------------------------+ +| Model | Type | Transient? | Inputs | +| | | +----------------+---------------------+------------+----------------+ +| | | | POA irradiance | Ambient temperature | Wind speed | Downwelling IR | ++===========================================+========+============+================+=====================+============+================+ +| :py:func:`~pvlib.temperature.faiman` | either | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ +| :py:func:`~pvlib.temperature.faiman_rad` | either | | ✓ | ✓ | ✓ | ✓ | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ +| :py:func:`~pvlib.temperature.fuentes` | cell | ✓ | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ +| :py:func:`~pvlib.temperature.noct_sam` | cell | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ +| :py:func:`~pvlib.temperature.pvsyst_cell` | cell | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ +| :py:func:`~pvlib.temperature.ross` | cell | | ✓ | ✓ | | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ +| :py:func:`~pvlib.temperature.sapm_cell` | cell | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ +| :py:func:`~pvlib.temperature.sapm_module` | module | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ + + +Model parameters +---------------- + +Some temperature model functions provide default values for their parameters, +and several additional sets of temperature model parameter values are +available in :py:data:`pvlib.temperature.TEMPERATURE_MODEL_PARAMETERS`. +However, these generic values may not be suitable for all modules. + +Module-specific values can be obtained via testing, for example following +the IEC 61853-2 standard. + +Currently, pvlib provides no functionality for fitting parameter values +using measured temperature. + + +Other functions +--------------- + +pvlib also provides a few other functions for temperature modeling: + +- :py:func:`~pvlib.temperature.prilliman`: an "add-on" model that introduces + transience to steady-state models. +- :py:func:`~pvlib.temperature.sapm_cell_from_module`: a model for + estimating cell temperature from module temperature. +- :py:func:`~pvlib.temperature.generic_linear`: a generic linear model form, + equivalent to several conventional temperature models. diff --git a/docs/sphinx/source/whatsnew/v0.13.2.rst b/docs/sphinx/source/whatsnew/v0.13.2.rst index d4cd10b5e7..b282d2a93a 100644 --- a/docs/sphinx/source/whatsnew/v0.13.2.rst +++ b/docs/sphinx/source/whatsnew/v0.13.2.rst @@ -46,6 +46,7 @@ Enhancements Documentation ~~~~~~~~~~~~~ * Provide an overview of single-diode modeling functionality in :ref:`singlediode`. (:pull:`2565`) +* Provide an overview of temperature modeling functionality in :ref:`temperature`. (:pull:`2591`) Testing From d5699d1059817ff0c7ac99c59290e38066b2d481 Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Tue, 4 Nov 2025 08:30:28 -0500 Subject: [PATCH 02/11] Apply suggestions from code review Co-authored-by: Cliff Hansen --- .../modeling_topics/temperature.rst | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index e3dc6afc28..67d27872f0 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -5,7 +5,7 @@ Temperature models pvlib provides a variety of models for predicting the operating temperature of a PV module from irradiance and weather inputs. These models range from -simple empirical equations requiring just a few multiplications to complex +simple empirical equations requiring just a few multiplications to more complex thermal balance models with numerical integration. Types of models @@ -14,8 +14,8 @@ Types of models Temperature models predict one of two quantities: - *module temperature*: the temperature as measured at the back surface - of a PV module. Easy to measure, but not directly related to PV - efficiency. + of a PV module. Easy to measure, but usually a few degrees less + than the cell temperature which determines efficiency. - *cell temperature*: the temperature of the PV cell itself. The relevant temperature for PV modeling, but almost never measured directly. @@ -24,8 +24,8 @@ temperature. Temperature models estimate these quantities using inputs like incident irradiance, ambient temperature, and wind speed. Each model also takes a set of parameter values that represent how a PV module responds to -those inputs. Different parameter values may be used for different PV -module technologies and/or the mounting conditions of the module. +those inputs. Parameter values generally depend on both the PV +module technologies and the mounting conditions of the module. Another way to classify temperature models is whether they account for the thermal inertia of a PV module. Temperature models are either: @@ -36,7 +36,7 @@ the thermal inertia of a PV module. Temperature models are either: - *transient*: the module's thermal inertia is included in the model, causing a lag in modeled temperature change following changes in the inputs. -Other effects that temperature models may consider include variation in +Other effects that temperature models may consider include the photoconversion efficiency and radiative cooling. The temperature models currently available in pvlib are summarized in the @@ -71,7 +71,8 @@ Model parameters Some temperature model functions provide default values for their parameters, and several additional sets of temperature model parameter values are available in :py:data:`pvlib.temperature.TEMPERATURE_MODEL_PARAMETERS`. -However, these generic values may not be suitable for all modules. +However, these generic values may not be suitable for all modules and mounting +configurations. Module-specific values can be obtained via testing, for example following the IEC 61853-2 standard. @@ -85,8 +86,8 @@ Other functions pvlib also provides a few other functions for temperature modeling: -- :py:func:`~pvlib.temperature.prilliman`: an "add-on" model that introduces - transience to steady-state models. +- :py:func:`~pvlib.temperature.prilliman`: an "add-on" model that reprocesses + the output of a steady-state model to apply transient effects. - :py:func:`~pvlib.temperature.sapm_cell_from_module`: a model for estimating cell temperature from module temperature. - :py:func:`~pvlib.temperature.generic_linear`: a generic linear model form, From 94d2a71d2d11cad0728f5200bbb4c92e3f0dd172 Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Thu, 20 Nov 2025 09:31:22 -0500 Subject: [PATCH 03/11] Apply suggestions from code review Co-authored-by: RDaxini <143435106+RDaxini@users.noreply.github.com> --- docs/sphinx/source/user_guide/modeling_topics/temperature.rst | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index 67d27872f0..567560d33a 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -14,13 +14,11 @@ Types of models Temperature models predict one of two quantities: - *module temperature*: the temperature as measured at the back surface - of a PV module. Easy to measure, but usually a few degrees less + of a PV module. Easy to measure, but usually less than the cell temperature which determines efficiency. - *cell temperature*: the temperature of the PV cell itself. The relevant temperature for PV modeling, but almost never measured directly. -Cell temperature is typically thought to be slightly higher than module -temperature. Temperature models estimate these quantities using inputs like incident irradiance, ambient temperature, and wind speed. Each model also takes a set of parameter values that represent how a PV module responds to From 13d4138d16e0b5ecb124c14d7b3fc096aa99a09f Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Thu, 20 Nov 2025 09:41:23 -0500 Subject: [PATCH 04/11] add mention of parameter conversion with GenericLinearModel --- docs/sphinx/source/user_guide/modeling_topics/temperature.rst | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index 67d27872f0..28281d397c 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -77,6 +77,10 @@ configurations. Module-specific values can be obtained via testing, for example following the IEC 61853-2 standard. +Parameter values for one model (e.g. ``u0``, ``u1`` for :py:func:`~pvlib.temperature.faiman`) +can be converted to another model (e.g. ``u_c``, ``u_v`` for :py:func:`~pvlib.temperature.pvsyst_cell`) +using :py:class:`~pvlib.temperature.GeneralLinearModel`. + Currently, pvlib provides no functionality for fitting parameter values using measured temperature. From 0a25860cad16f9179755cca55387fdbfdc28e0dc Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Thu, 20 Nov 2025 09:50:55 -0500 Subject: [PATCH 05/11] add note about IR --- .../modeling_topics/temperature.rst | 44 ++++++++++--------- 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index 63bfccb04d..33e2686521 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -40,27 +40,29 @@ photoconversion efficiency and radiative cooling. The temperature models currently available in pvlib are summarized in the following table: -+-------------------------------------------+--------+------------+--------------------------------------------------------------------+ -| Model | Type | Transient? | Inputs | -| | | +----------------+---------------------+------------+----------------+ -| | | | POA irradiance | Ambient temperature | Wind speed | Downwelling IR | -+===========================================+========+============+================+=====================+============+================+ -| :py:func:`~pvlib.temperature.faiman` | either | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ -| :py:func:`~pvlib.temperature.faiman_rad` | either | | ✓ | ✓ | ✓ | ✓ | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ -| :py:func:`~pvlib.temperature.fuentes` | cell | ✓ | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ -| :py:func:`~pvlib.temperature.noct_sam` | cell | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ -| :py:func:`~pvlib.temperature.pvsyst_cell` | cell | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ -| :py:func:`~pvlib.temperature.ross` | cell | | ✓ | ✓ | | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ -| :py:func:`~pvlib.temperature.sapm_cell` | cell | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ -| :py:func:`~pvlib.temperature.sapm_module` | module | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+----------------+ ++-------------------------------------------+--------+------------+---------------------------------------------------------------------------+ +| Model | Type | Transient? | Inputs | +| | | +----------------+---------------------+------------+-----------------------+ +| | | | POA irradiance | Ambient temperature | Wind speed | Downwelling IR [#f1]_ | ++===========================================+========+============+================+=====================+============+=======================+ +| :py:func:`~pvlib.temperature.faiman` | either | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.faiman_rad` | either | | ✓ | ✓ | ✓ | ✓ | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.fuentes` | cell | ✓ | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.noct_sam` | cell | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.pvsyst_cell` | cell | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.ross` | cell | | ✓ | ✓ | | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.sapm_cell` | cell | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.sapm_module` | module | | ✓ | ✓ | ✓ | | ++-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ + +.. [#f1] Downwelling infrared radiation. Model parameters From 34ef1591baa1cfd0b093a350fe721e88a553a536 Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Thu, 20 Nov 2025 09:55:21 -0500 Subject: [PATCH 06/11] move "other functions" up to below the table --- .../modeling_topics/temperature.rst | 24 +++++++++---------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index 33e2686521..a0cbe251e0 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -65,6 +65,17 @@ following table: .. [#f1] Downwelling infrared radiation. +In addition to the core models above, pvlib provides several other functions +for temperature modeling: + +- :py:func:`~pvlib.temperature.prilliman`: an "add-on" model that reprocesses + the output of a steady-state model to apply transient effects. +- :py:func:`~pvlib.temperature.sapm_cell_from_module`: a model for + estimating cell temperature from module temperature. +- :py:func:`~pvlib.temperature.generic_linear`: a generic linear model form, + equivalent to several conventional temperature models. + + Model parameters ---------------- @@ -83,16 +94,3 @@ using :py:class:`~pvlib.temperature.GeneralLinearModel`. Currently, pvlib provides no functionality for fitting parameter values using measured temperature. - - -Other functions ---------------- - -pvlib also provides a few other functions for temperature modeling: - -- :py:func:`~pvlib.temperature.prilliman`: an "add-on" model that reprocesses - the output of a steady-state model to apply transient effects. -- :py:func:`~pvlib.temperature.sapm_cell_from_module`: a model for - estimating cell temperature from module temperature. -- :py:func:`~pvlib.temperature.generic_linear`: a generic linear model form, - equivalent to several conventional temperature models. From b2ecc30096220135c3f6587483f688e4c09ff5d9 Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Thu, 20 Nov 2025 10:09:40 -0500 Subject: [PATCH 07/11] fix spelling --- docs/sphinx/source/user_guide/modeling_topics/temperature.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index a0cbe251e0..b8471c780c 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -90,7 +90,7 @@ the IEC 61853-2 standard. Parameter values for one model (e.g. ``u0``, ``u1`` for :py:func:`~pvlib.temperature.faiman`) can be converted to another model (e.g. ``u_c``, ``u_v`` for :py:func:`~pvlib.temperature.pvsyst_cell`) -using :py:class:`~pvlib.temperature.GeneralLinearModel`. +using :py:class:`~pvlib.temperature.GenericLinearModel`. Currently, pvlib provides no functionality for fitting parameter values using measured temperature. From bbf9bbd2be930688347ed46cc12ffac6f4d5a74f Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Wed, 3 Dec 2025 09:07:56 -0500 Subject: [PATCH 08/11] Apply suggestions from code review Co-authored-by: Anton Driesse --- .../user_guide/modeling_topics/temperature.rst | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index b8471c780c..4c0358bffb 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -14,7 +14,7 @@ Types of models Temperature models predict one of two quantities: - *module temperature*: the temperature as measured at the back surface - of a PV module. Easy to measure, but usually less + of a PV module. Easy to measure, but usually marginally less than the cell temperature which determines efficiency. - *cell temperature*: the temperature of the PV cell itself. The relevant temperature for PV modeling, but almost never measured directly. @@ -23,9 +23,10 @@ Temperature models estimate these quantities using inputs like incident irradiance, ambient temperature, and wind speed. Each model also takes a set of parameter values that represent how a PV module responds to those inputs. Parameter values generally depend on both the PV -module technologies and the mounting conditions of the module. +module technologies, the mounting conditions of the module +and on any weather parameters that are not included in the model. -Another way to classify temperature models is whether they account for +Another aspect of temperature models is whether they account for the thermal inertia of a PV module. Temperature models are either: - *steady-state*: the module is assumed to have been at the specified operating @@ -83,10 +84,16 @@ Some temperature model functions provide default values for their parameters, and several additional sets of temperature model parameter values are available in :py:data:`pvlib.temperature.TEMPERATURE_MODEL_PARAMETERS`. However, these generic values may not be suitable for all modules and mounting -configurations. +configurations. It should be noted that using the default parameter values for each +model generally leads to different modules temperature predictions. This alone +does not mean one model is better than another; it's just evidence that the measurements +used to derive the default parameter values were taken on different PV systems in different +locations under different conditions. + Module-specific values can be obtained via testing, for example following -the IEC 61853-2 standard. +the IEC 61853-2 standard for the Faiman model; however, such values still do not capture +the dependency of temperature on system design and other variables. Parameter values for one model (e.g. ``u0``, ``u1`` for :py:func:`~pvlib.temperature.faiman`) can be converted to another model (e.g. ``u_c``, ``u_v`` for :py:func:`~pvlib.temperature.pvsyst_cell`) From e2fb42643176eea3ea11bf9bda14534a539af9b9 Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Wed, 3 Dec 2025 09:19:51 -0500 Subject: [PATCH 09/11] feedback from review Co-Authored-By: Ioannis Sifnaios <88548539+IoannisSifnaios@users.noreply.github.com> --- docs/sphinx/source/user_guide/modeling_topics/temperature.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index 4c0358bffb..1fd369c897 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -23,7 +23,7 @@ Temperature models estimate these quantities using inputs like incident irradiance, ambient temperature, and wind speed. Each model also takes a set of parameter values that represent how a PV module responds to those inputs. Parameter values generally depend on both the PV -module technologies, the mounting conditions of the module +module technologies, the mounting configuration of the module, and on any weather parameters that are not included in the model. Another aspect of temperature models is whether they account for From 62faf38b2bc2316df899b1a6f9e70b92b005ac4f Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Wed, 3 Dec 2025 09:42:24 -0500 Subject: [PATCH 10/11] more changes from review --- .../modeling_topics/temperature.rst | 58 ++++++++++--------- 1 file changed, 30 insertions(+), 28 deletions(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index 1fd369c897..10874a24ef 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -25,6 +25,10 @@ a set of parameter values that represent how a PV module responds to those inputs. Parameter values generally depend on both the PV module technologies, the mounting configuration of the module, and on any weather parameters that are not included in the model. +Note that, despite models conventionally being associated with either +cell or module temperature, it is actually the parameter values that determine +which of the two temperatures are predicted, as they will produce the same +type of temperature from which they were originally derived. Another aspect of temperature models is whether they account for the thermal inertia of a PV module. Temperature models are either: @@ -41,31 +45,32 @@ photoconversion efficiency and radiative cooling. The temperature models currently available in pvlib are summarized in the following table: -+-------------------------------------------+--------+------------+---------------------------------------------------------------------------+ -| Model | Type | Transient? | Inputs | -| | | +----------------+---------------------+------------+-----------------------+ -| | | | POA irradiance | Ambient temperature | Wind speed | Downwelling IR [#f1]_ | -+===========================================+========+============+================+=====================+============+=======================+ -| :py:func:`~pvlib.temperature.faiman` | either | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ -| :py:func:`~pvlib.temperature.faiman_rad` | either | | ✓ | ✓ | ✓ | ✓ | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ -| :py:func:`~pvlib.temperature.fuentes` | cell | ✓ | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ -| :py:func:`~pvlib.temperature.noct_sam` | cell | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ -| :py:func:`~pvlib.temperature.pvsyst_cell` | cell | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ -| :py:func:`~pvlib.temperature.ross` | cell | | ✓ | ✓ | | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ -| :py:func:`~pvlib.temperature.sapm_cell` | cell | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ -| :py:func:`~pvlib.temperature.sapm_module` | module | | ✓ | ✓ | ✓ | | -+-------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ ++----------------------------------------------+--------+------------+---------------------------------------------------------------------------+ +| Model | Type | Transient? | Inputs | +| | | +----------------+---------------------+------------+-----------------------+ +| | | | POA irradiance | Ambient temperature | Wind speed | Downwelling IR [#f1]_ | ++==============================================+========+============+================+=====================+============+=======================+ +| :py:func:`~pvlib.temperature.faiman` | either | | ✓ | ✓ | ✓ | | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.faiman_rad` | either | | ✓ | ✓ | ✓ | ✓ | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.fuentes` | either | ✓ | ✓ | ✓ | ✓ | | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.generic_linear` | cell | | ✓ | ✓ | ✓ | | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.noct_sam` | cell | | ✓ | ✓ | ✓ | | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.pvsyst_cell` | cell | | ✓ | ✓ | ✓ | | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.ross` | cell | | ✓ | ✓ | | | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.sapm_cell` | cell | | ✓ | ✓ | ✓ | | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ +| :py:func:`~pvlib.temperature.sapm_module` | module | | ✓ | ✓ | ✓ | | ++----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ .. [#f1] Downwelling infrared radiation. - In addition to the core models above, pvlib provides several other functions for temperature modeling: @@ -73,8 +78,6 @@ for temperature modeling: the output of a steady-state model to apply transient effects. - :py:func:`~pvlib.temperature.sapm_cell_from_module`: a model for estimating cell temperature from module temperature. -- :py:func:`~pvlib.temperature.generic_linear`: a generic linear model form, - equivalent to several conventional temperature models. Model parameters @@ -90,14 +93,13 @@ does not mean one model is better than another; it's just evidence that the meas used to derive the default parameter values were taken on different PV systems in different locations under different conditions. +Parameter values for one model (e.g. ``u0``, ``u1`` for :py:func:`~pvlib.temperature.faiman`) +can be converted to another model (e.g. ``u_c``, ``u_v`` for :py:func:`~pvlib.temperature.pvsyst_cell`) +using :py:class:`~pvlib.temperature.GenericLinearModel`. Module-specific values can be obtained via testing, for example following the IEC 61853-2 standard for the Faiman model; however, such values still do not capture the dependency of temperature on system design and other variables. -Parameter values for one model (e.g. ``u0``, ``u1`` for :py:func:`~pvlib.temperature.faiman`) -can be converted to another model (e.g. ``u_c``, ``u_v`` for :py:func:`~pvlib.temperature.pvsyst_cell`) -using :py:class:`~pvlib.temperature.GenericLinearModel`. - Currently, pvlib provides no functionality for fitting parameter values using measured temperature. From 7527867210569f321799c53db606152f0c826458 Mon Sep 17 00:00:00 2001 From: Kevin Anderson Date: Wed, 3 Dec 2025 16:03:43 -0500 Subject: [PATCH 11/11] Update docs/sphinx/source/user_guide/modeling_topics/temperature.rst --- docs/sphinx/source/user_guide/modeling_topics/temperature.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst index 10874a24ef..5a6e04c47f 100644 --- a/docs/sphinx/source/user_guide/modeling_topics/temperature.rst +++ b/docs/sphinx/source/user_guide/modeling_topics/temperature.rst @@ -56,7 +56,7 @@ following table: +----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ | :py:func:`~pvlib.temperature.fuentes` | either | ✓ | ✓ | ✓ | ✓ | | +----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ -| :py:func:`~pvlib.temperature.generic_linear` | cell | | ✓ | ✓ | ✓ | | +| :py:func:`~pvlib.temperature.generic_linear` | either | | ✓ | ✓ | ✓ | | +----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+ | :py:func:`~pvlib.temperature.noct_sam` | cell | | ✓ | ✓ | ✓ | | +----------------------------------------------+--------+------------+----------------+---------------------+------------+-----------------------+