Series resistance output

The Series resistance output tab presents the results of the analytical grid resistance calculation performed by SunSolve Power. It breaks down the total cell series resistance into contributions from each metal element and contact interface in the electrode grid, giving visibility into where resistive losses occur.

For the underlying physics and equations, see the series resistance calculation technical reference.

When is it calculated?

The series resistance output is populated whenever SunSolve Power runs the grid solver. This happens automatically as part of a full simulation run, but can also be triggered independently from the Electrodes input tab.

The tab is only visible when the electrical solver is enabled and the electrode configuration defines a solvable grid. If the grid cannot be solved (for example, because both contacts are set to “None”), the tab displays a message explaining why the grid resistance cannot be calculated, along with guidance to define a solvable grid on the Electrodes input tab.

Display options

Two controls appear at the top of the tab:

• Show details — a checkbox that toggles between a summary view (one row per contact side plus internal elements) and a detailed view that lists every grid element individually.
• Significant figures — controls the number of significant figures shown in the numeric outputs.

Output table structure

The output is presented as a single table. Each row corresponds to a grid element or group of elements, and the columns report specific quantities for that element.

Column headings

ColumnUnitDescription$R_s$, $\Omega \cdot \text{cm}^2$, Total series resistance contribution of the element. This is the sum of $R_{s\text{ grid}}$ and $R_{s\text{ contact}}$.$R_{s\text{ grid}}$, $\Omega \cdot \text{cm}^2$, Resistive loss from current flowing through the metal element itself (the grid or bulk metal resistance).$R_{s\text{ contact}}$, $\Omega \cdot \text{cm}^2$, Resistive loss at the contact interface between the element and the substrate or adjoining element.Metal coverage, %, Fraction of the cell area covered by this metal element.$A$, $\text{cm}^2$, Total metal contact area of the element.$V$, $\text{cm}^3$, Total metal volume of the element.

Row groups

The table is organised into the following sections, from top to bottom.

Front/rear metal (or outer/inner for interdigitated cells)

For a standard front-and-rear contact configuration the two sections are labelled Front metal and Rear metal. For interdigitated back-contact cells the labels change to Outer metal and Inner metal to reflect the electrode arrangement.

When Show details is enabled, each section lists the individual grid elements in the order they appear in the current path:

• Ribbons — the interconnection ribbons (tabbing) that carry current away from the cell.
• Busbars — the busbars that collect current from multiple fingers and route it to the pads.
• Fingers (or coating) — the fingers that collect current directly from the semiconductor surface. If the contact layout is set to “Coating” rather than “Grid”, this row is labelled “coating” instead.

When Show details is disabled, a single summary row is shown for each contact side (e.g. “Front metal total”), with the values representing the combined contribution of all metal elements on that side.

Elements that are not present in the current grid configuration (for example, ribbons when no ribbons are defined) are hidden from the table.

Internal elements

This section appears when the simulation includes internal resistance contributions that are not part of the metal grid. These can include:

• Front skin — lateral sheet resistance of the front conductive layer (emitter or TCO).
• Rear skin — lateral sheet resistance of the rear conductive layer.
• Base — bulk resistance through the wafer thickness.

When Show details is enabled, each internal element is listed on its own row showing only its $R_s$ contribution (the grid, contact, coverage, area and volume columns are not applicable). When details are hidden, a single “Internal” summary row is shown.

Calculated total

This row appears only in the detailed view and shows the sum of all grid-element and internal-element contributions. It represents the series resistance as calculated by the grid solver before any user-defined additional resistance is applied.

Additional (user defined)

In the summary view, this row shows any additional series resistance that has been manually specified by the user in the electrical input settings. This value is added on top of the calculated grid resistance.

Total for cell

The final row in the summary view shows the total series resistance for the cell: the calculated grid resistance plus any user-defined additional resistance. This is the value of $R_s$ that is used in the equivalent circuit model when solving the cell IV curve.

Copying data

A Copy table data button below the table copies the contents of the output table to the clipboard in a format suitable for pasting into a spreadsheet.

Relationship to other outputs

The total series resistance calculated on this tab feeds directly into the equivalent circuit model, where it determines the slope of the cell IV curve around the maximum power point and influences the fill factor.

The electrode geometry that drives this calculation is configured on the Electrodes input tab (see the electrodes documentation).