Module — Cell layout

The cell layout defines the number and position of the solar cells in the module, as well as the module dimensions.

The cell layout is defined on the Layout tab of the module popover, which appears when loading or previewing a module.

The cells are arranged in an XY grid and defined by the number of

Columns $N_{x}$ and
Rows $N_{y}$ .

The bottom-left cell is labelled {X = 0, Y = 0}.

Other inputs depend on whether the module is simple or complex.

Module type

Additional inputs

Simple, Module dimensions.

Complex, Cell groupings,, space around cell groupings,, space between cells,, and space at the module perimeter. Module dimensions are calculated from the cell dimensions,, cell spacing,, and frame.

Irrespective of whether the module is simple or complex, the electrical connection between cells is defined in the same way, as described in the electrical layout.

Simple modules

For a simple module, the user defines the module dimensions:

Width $X_{M}$ ,
Length $Y_{M}$ , and
Thickness $Z_{M}$ .

If the simple module does not have a frame, it is treated as a rectangular prism with these dimensions. The active area is the same as its total area.

If the simple module has a frame,

$X_{M}$ and $Y_{M}$ include the frame dimensions;
the active area is reduced by the $X$ and $Y$ dimensions of the frame; and
$Z_{M}$ is the combined thickness of the encapsulants and cells, but excludes the thickness of the frame.

With or without a frame, the active area of a simple module is divided into a grid of equal-sized cells with no space between or around the cells.

The figure below illustrates these rules. It depicts two simple modules with the same dimensions, $X_{M}$ , $Y_{M}$ and $Z_{M}$ , where the right-hand module has a frame and the left-hand module does not. The active area, shown in blue, is divided into three columns and four rows ( $N_{x} = 3$ , $N_{y} = 4$ ). Notice that the module with the frame has smaller cells.

Simple module dimensions

The optics of the active region are defined by the simple module optics.

Complex modules

Complex modules allow you to define a detailed cell layout, with spacing between cells, around groups of cells, and at the perimeter of the module.

The figure below gives an example. It is a conventional module containing 144 half-cut solar cells, as generated by SunSolve. The cell spacing, the cell groups, the perimeter and the frame are evident.

Frame and perimeter dimensions

For complex modules, SunSolve ray traces the incident light to the surface of the module, and then continues the ray tracing inside the module. It thereby accounts for the interaction of light with the module layers, like the glass, encapsulants, backsheet and cells.

Complex modules can therefore simulate the complicated optics between the solar cells of a module. Depending on how the layers have been configured, light might pass through the module, like in a semitransparent module used in agriPV; or it might be reflected and scattered by a backsheet, giving the light the chance to be internally reflected at the glass–air interface and on to adjacent cells, like in a conventional module used on rooftops or in utility-scale plants.

The module dimensions are not entered directly. They are calculated from the cell dimensions, the cell spacing, the perimeter and the frame. See below.

We now describe the additional inputs for complex modules. They are identical in SunSolve Power and SunSolve Yield.

Cell spacing

Cell spacing is defined by the separation between adjacent cells in the X and Y dimensions:

X separation $X_{sep}$ , and
Y separation $Y_{sep}$ .

The figure below shows how $X_{sep}$ and $Y_{sep}$ define the distance between the edge of the solar cell and the edge of the unit cell. (The solar cell and its unit cell are concentric.)

Cell groups

Cell groups can be used to mimic modules whose cell spacing is not identical throughout, such as in the conventional half-cut module (shown above) that has a large vertical gap at the centre.

When cell groups are enabled, the following inputs appear:

Groups per row $N_{g x}$ ,
Groups per column $N_{g y}$ ,
X separation $X_{g}$ — the extra spacing between groups in the X direction, and
Y separation $Y_{g}$ — the extra spacing between groups in the Y direction.

The inputs for $X_{g}$ and $Y_{g}$ are only visible when there is more than one group per row or column. The group spacing is in addition to the cell spacing.

Note that the group separation does not modify the electrical circuit. E.g., the series resistance of the ribbons is not increased due to group spacing.

Module perimeter

The module perimeter is the space around the outermost cells of the module. It defines the gap between the outermost unit cells and the frame, or if there is no frame, the edge of the module.

When ‘include perimeter’ is checked, the perimeter’s dimensions are defined by these four inputs:

Left $X_{p 1}$ ,
Right $X_{p 2}$ ,
Bottom $Y_{p 1}$ , and
Top $Y_{p 2}$ .

When unchecked, there is no perimeter and $X_{p 1} = X_{p 2} = Y_{p 1} = Y_{p 2} = 0$ .

Importantly, and as illustrated in the figures below, the group spacing and the perimeter are in addition to the spacing within the unit cell.

Examples

These examples help define the approach taken by the cell layouts.

The first figure depicts a module with a frame, a perimeter, 2 cells in each row and 2 cells in each column, where the cells are contained in a single group. Note how the dimensions of the perimeter do not include the cell spacing defined for the unit cell.

Frame and perimeter dimensions

The next figure depicts a module with no frame, a perimeter, 4 cells in each row and 9 cells in each column, grouped into 2 cell groups in the X direction and 3 cell groups in the Y direction.

Cell group dimensions

Standard layouts

SunSolve provides preset standard module layouts that can be loaded to quickly configure common module types. These presets set the cell count, spacing, and arrangement. Standard layouts can only be loaded when the inputs are not locked (i.e., before a simulation).

Calculated module dimensions

In the layout section of the module popover, the following are displayed:

Single cell area $A_{c}$ , as determined by the cell’s shape and dimensions.
Total cell area $A_{total cell}$ , the combined area of all cells in the module.
Cell gap area, the total area of the module excluding the cells and frame. This area contains glass, encapsulants and backsheets but no cells or frame. It is necessarily zero for a simple module.
Frame area $A_{frame}$ .
Module area $A_{module}$ , the overall area of the module including the frame.
X and Y dimensions $X_{M}$ and $Y_{M}$ , the width and length of the module.

The equations used to calculate these dimensions are

A_{total cell} = A_{c} \times N_{x} \times N_{y}

A_{module} = X_{M} \times Y_{M}

A_{frame} = A_{module} - A_{inner}

A_{inner} = X_{inner} \times Y_{inner}

X_{M} = X_{inner} + F_{x 1} + F_{x 2}

Y_{M} = Y_{inner} + F_{y 1} + F_{y 2}

X_{inner} = N_{x} \times (X_{c} + X_{sep}) + (N_{g x} - 1) \times X_{g} + X_{p 1} + X_{p 2}

Y_{inner} = N_{y} \times (Y_{c} + Y_{sep}) + (N_{g y} - 1) \times Y_{g} + Y_{p 1} + Y_{p 2}

where $N_{g x}$ and $N_{g y}$ are the number of cell groups (equal to 1 when cell groups are disabled); $X_{g}$ and $Y_{g}$ are the group spacings; $X_{p 1}$ , $X_{p 2}$ , $Y_{p 1}$ , and $Y_{p 2}$ are the perimeter distances (equal to 0 when the perimeter is disabled); $F_{x 1}$ , $F_{x 2}$ , $F_{y 1}$ , and $F_{y 2}$ are the frame widths (equal to 0 when there is no frame); and $X_{c}$ and $Y_{c}$ are the maximum dimensions of each solar cell.