# pvl_sapmcelltemp

Estimate cell temperature from irradiance, windspeed, ambient temperature, and SAPM module parameters.

## Contents

- Syntax
- Description
- Inputs
- Outputs
- Example
- References
- See Also

## Syntax

`Tcell = pvl_sapmcelltemp(E, E0, a, b, windspeed, Tamb, deltaT)`

`[Tcell Tmodule] = pvl_sapmcelltemp(E, E0, a, b, windspeed, Tamb, deltaT)`

## Description

Estimate cell and module temperatures using the Sandia Array Performance Model (SAPM) [1], when given the incident irradiance, wind speed, and ambient temperature.

The cell temperature model is

where

- is the cell temperature (C).
- is the module backsurface temperature (C).
- is the ambient air temperature (C).
- is the wind speed (m/s).
- , and are parameters.

## Inputs

- `E` - Total incident irradiance in W/m^2. E must be a scalar or a vector of the same size as windspeed, and Tamb. Must be >=0.
- `E0` - Reference irradiance used when determining delta T, in W/m^2. E0 must be a scalar. Must be >=0. Typically equals 1,000 W/m^2;
- `a` - SAPM module parameter for establishing the upper limit for module temperature at low wind speeds and high solar irradiance (see SAPM eqn. 11). Must be a scalar.
- `b` - SAPM module parameter for establishing the rate at which the module temperature drops as wind speed increases (see SAPM eqn. 11). Must be a scalar.
- `windspeed` - Wind speed in m/s at a height of 10 meters. windspeed must be a scalar or a vector of the same size as E and Tamb. Must be >=0;
- `Tamb` - Ambient dry bulb temperature in degrees C. Tamb must be a scalar or a vector of the same size as windspeed and E. Must be >= -273.15.
- `deltaT` - SAPM module parameter giving the temperature difference between the cell and module back surface at the reference irradiance, `E0`. Must be a numeric scalar >=0.

## Outputs

- `Tcell` - A column vector of cell temperatures in degrees C.
- `Tmodule` - A column vector of module back temperature in degrees C.

## Example

Calculate cell temperature for a typical glass/cell/polymer sheet module mounted on an open rack. a, b, and deltaT parameter from [1], Table 1. Sample weather conditions are used.

    deltaT = 3;
    a = -3.56;
    b = -0.075;
    E = 800; % Incident irradiance
    E0 = 1000;
    windspeed = 5; %5 m/s
    Tamb = 10; %10 deg C
    Tcell = pvl_sapmcelltemp(E, E0, a, b, windspeed, Tamb, deltaT)

    Tcell =

       28.0366

## References

[1] King, D. et al, 2004, "Sandia Photovoltaic Array Performance Model", SAND2004-3535, Sandia National Laboratories, Albuquerque, NM Web Link

## See Also

`pvl_samp`, `pvl_sapmmoduledb`

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