Most of the countries in the International Solar Alliance lie

Most International Solar Alliance members lie between the Tropic of Cancer and the Tropic of Capricorn, where sunlight is abundant year-round.

Placing them above the Tropic of Cancer would exclude the sun-rich tropical belt the alliance targets.

Placing them below the Tropic of Cancer alone ignores members north of the equator.

Confining them to the Southern Hemisphere overlooks the many northern tropical members.

The alliance was launched by India and France to promote solar deployment.

This sunbelt receives the strongest and most consistent solar radiation.