Rebutting your LLM’s points:

1. “Older” houses in much of Europe are often made of stone, newer are frequently cinderblock, and the roof beams in both are massive. They’re holding up tile and slate roofs - the weight of solar panels is a rounding error, and not the concern it is with shoddy US stick-frame construction. So if that’s the “main reason” we’re doing pretty well already.

2. Sub-optimal angle just means the panel doesn’t produce AS MUCH power as it theoretically could. Not that it produces none, and many sub-optimal placements are still financially viable. Beyond that, any south-facing roof available is going to do very well.

3. Fire risks are again much lower on the very common hard-surface roofs. And that same space that allows the oxygen in also separates the fire from the roof, so the only things burning are the panels themselves and the fire soesn’t spread as it might with a ground-based installation which, by the way, also has air under the panels and are often over grass.

4. Higher installation and maintenance costs are partially offset by the fact that the cost of land purchase and taxes are €0. That was already covered by the building’s main use. Then you can add the social and financial benefit of keeping those fields in food production. Moving away from animal agriculture would not only mean more food available locally, but also for export as crop yields in other places fall due to climate change.

Finally, the whole framing presents a false dichotomy. This doesn’t have to be an either-or proposition - both-and is an option. We can have solar panels on buildings AND in fields. We can convert growing fields from feed production to food production AND put solar panels on the former pig farms that can’t support crops. Particularly in warmer climates (maybe less applicable in Denmark) we can even raise the solar panels a bit higher AND still grow crops underneath (Agrivoltaics)!