# Model energy

Choose a simulation model, run it, and review the results.

Source: https://docs.staging.solesca.com/editor/simulate/

The **Model** control is at the top of the editor. Its model selector chooses the simulation model for the design. The same selection is used for downloads that contain energy results.

## Choose a model

| Model | When it is available |
| --- | --- |
| **Solesca Core** | The default for a new flat design. |
| **Solesca Pro** | Designs with terrain tracking or engineering configured. Terrain designs use Pro. |
| **NREL SAM** | An alternative for flat designs using NREL's System Advisor Model. |
| **SolarFarmer** | Requires an Engineering seat and uploaded PAN and OND files for the design's equipment. It is unavailable for terrain and designs using SolarEdge optimizers. |

The selector offers models that are available for your design and access. Enabling terrain switches the design to **Solesca Pro** if needed.

On SolarEdge designs, SAM displays a notice about how it represents strings. Your design's strings stay unchanged. Core and Pro support modeling the specified optimizer configuration.

## Run

1. Check the fields, equipment, inverter groups, weather, and [loss settings](https://docs.staging.solesca.com/editor/losses/).
2. Choose the model in the selector.
3. Click **Model** or press `M`.
4. Read the results panel when the run finishes.

If the design needs an inverter-group correction, the app explains the issue and directs you to the affected group. Fix it before continuing.

Solesca Pro can take a few minutes. Its run continues if you leave the design. Editing the design cancels that run.

## Results

The results panel shows **Module area**, **DC nameplate**, **AC nameplate**, and **DC/AC ratio**, followed by **Energy**, **Specific yield**, **Shade losses**, and **Performance ratio** where the chosen model reports them.

A missing value is shown as a dash, not zero. The panel can show changes from the previous run with the same model.

Clicking **Model** again reopens the current results when the design and model have not changed. During a run it reopens the progress panel. After a change, run the model again to update the results.

## Errors and warnings

A failed run displays a message explaining the problem. Check equipment selection, string allocation, required input files, and any highlighted group. If the message reports that modeling stopped, run it again. Use [Concierge](https://docs.staging.solesca.com/start/concierge/) if the error persists.

A shadow view is useful for inspecting the design, but it is not the annual energy result. See [Shadows](https://docs.staging.solesca.com/editor/map/#shadows).

## Downloads use the selected model

[Reports](https://docs.staging.solesca.com/downloads/report/) and [Energy files](https://docs.staging.solesca.com/downloads/energy/) use the selected model. Review the download options for model-specific limitations. CAD, rendering, Google Earth, and racking files do not run an energy model.