I lived in parts of Mexico where solar wouldn't be a great idea because peak demand was after sundown and air conditioning was rarely wanted or used. Quite a lot of the population lives over 2000m (6200ft) elevation where the weather is cool.<p>But I remember even decades ago that solar was already the main power source in small towns in remote parts of Coahuila and Chihuahua I used to bicycle through.<p>Even today along the steamy coasts and northern deserts it gets plenty hot and electricity demand is driven by air conditioning. Solar would seem likely to pay off fast in Sonora, Tamaulipas, Veracruz, Jalisco, and places like that. Even better would be the orderly and steady communities of Tabasco and the Yucatan that get so hot, receive much sun, and can sustain long term investments because the local economies have remained stable while growing.<p>But I don't recall ever reading about subsidies or utility companies paying solar customers for contributing back to the grid. Those are the two supports the solar industry loves in the USA. Without them, solar has to pay for itself in the most brutal way by just making electricity usage cheaper house by house.<p>I wonder @JGreenberger where the most exciting region is to promote household solar, whether larger collective or unidad habitacional installations are viable, and whether there is any kind of subsidy or reverse tariff arrangement to promote solar use.