Why not? Many of the most common franchise businesses have entry costs around $1 million
People would take out loans to afford them, or rent them from the real "franchise owner".
Not everybody aspires to a unicorn exit. Predictable returns are worth a lot too, even small ones. The drivers who took out loans for their medallions really got screwed when Uber came in, but if the demand for electricity drops catastrophically, we'll probably have bigger problems than a bit of debt.
2) you might need to have 10x that much (in just panels).
3) I'd be amazed if you could find financing for this.
Or you can do a deep tech startup like mini Varda. $1MM can get you far enough that you attract VC money and that’s all you need.
It might look more like a micro financing idea than a franchise. Most of the commercial-scale solar installations today are built by a developer and then either a) held in their portfolio or b) sold to a utility