This is not a situation limited to solar energy. In India we have the social technology to organize men and build large projects. The US had this technology 100 years ago, but we've lost it.
Trains
Delhi metro, phase 2: 77 miles of track, 85 stations, $2.9B, 3 years.
Hudson Yards NYC: 1 mile of track, 1 station, $2.5B, 9 years.
Green line expansion, Boston: 4 miles of track, 4 stations, $3.1B, 7 years (if all goes according to plan).
Space exploration
Mangalyaan mission to mars: $74M.
A movie about Matt Damon getting stuck on mars: $108M.