Do you mean investments in solar panel manufacturing, or something else? From what I understand solar panels are somewhat commoditized, and China has massive subsidies for their manufacturers. I wouldn't want to get in that game. If you mean battery R&D + manufacture, I think that could be promising
Aside from being a cool and useful library, this is a good example of what John Ousterhout calls "deep modules" in Philosophy of Software Design.
It's very easy to use the most basic version of this library (summon confetti) but you can get a lot out of it by exploring the options presented (snow, specific colours, different confetti effects, etc.).
The scale on the maps I showed is the same, which is the point. Toronto, as you point out, has a built up core, but Montreal spreads its density wider.