I just found out about this last night: EnviroMission[1] is looking for funding to build solar updraft towers that could radically change the world’s reliance on fossil fuels. The design is very simple, and at scale could generate massive amounts of power. They’ve been having trouble getting off the ground, unfortunately, but the technology is so promising that it should not be ignored. More info in [2].
1: http://www.enviromission.com.au/IRM/content/default.aspx
2: https://en.m.wikipedia.org/wiki/Solar_updraft_tower