Well even with a small file size, if you check ‘Statistics’ under ‘Model Info’…you have a very high number of polygons (edges and faces) in the model. +326 million is a lot. SketchUp is a surface modeler and performance tends to slow down as the polygon count climbs.
Here is the geometry count per solar panel…not high but when multiplied that many times it adds up fast!
One thought is to ask yourself if your project requires so much geometry per solar panel when it seems to me to be more about the array across the site that’s important. You can start by switching to an image for the solar cells. Here is the geometry on one panel when switched to using an image:
And here it is when swapped out with your previous version in the full site file. Still high at 168 mil polygons but you can next look at the support structures of the panels and see if you can reduce that as well. Using an extensions like Skimp, Transmutr or Artisan all have geometry reduction capabilities…my recommendation is to just save one component out to an external file…re-draw the supports with less polygons…and reload into overall model.
Lastly, you can ‘break’ the large array filed into smaller pieces by grouping and assigning to Tags. That way, while working, you can say toggle the supports or the panels on or off or even toggle areas such as ‘South’, ‘North Side’, etc on and off so that you’re only processing parts of the model at any given time.
If all else fails, turn edges and profiles off completely and that should help as well.