India, Nov. 26 -- Think of roof, and you see solar panels. Think of solar, and you see the energy generated during the day, powering appliances and even feeding into the grid, from which it can be bought back at night when the sun is not shining. It's the world's most uber solution, where each of us becomes a generator of electricity. It also works because solar is modular-the panels can fit almost anywhere, unlike thermal or nuclear generators. While building utility-scale solar plants requires vast amounts of land, which is always scarce and often contested, in this model every available roof becomes a power plant.

You may ask why I am expounding on the well-known advantages of rooftop solar. I believe the potential is enormous. Why, t...