These ideas, and the idea that they are frighteningly ambitious, clearly come from the personal experience of living in northern California and dealing with tech startups most of your time. These are largely first world problems. Here are some ambitious ideas: - distributed power generation that's cheap enough and renewable enough so people in rural parts of sub-Saharan Africa don't have brown outs anymore. - synthet…
Non consumption is traditionally a good place to start and I would suggest that high school & junior university level is the most disruptive place to start. Non-consumption of senior high school to junior university level education is something in great abundance in poor countries.
There is also probably a more incentive for potential students to play along in poor countries. A 9th-10th year dropout is more likely to be in that position because of access or soem other problem that technological innovation is good at dealing with. More importantly, the ROI on those 2-4 years of education is probably much higher.
If you were to go after job skills/ training as the point of attack (as opposed to general education) poor countries are also a great place to start. For a lot of skills there is demand at the bottom: bookkeeping, graphic design, programming, etc. Bringing a person making <$1-$2 per hour to a point where they can command a $3+ is fundamentally doable. That's a big incentive.