On Kites and Turning Wastewater into Fuels

In the economist article Power to the People, the challange is posed on how to get energy to people living in remote areas. I have two things I would like to share on this topic. First a short movie about Wind-powered Kites by Saul Griffith:
Think of it. In windy rural areas, every farm or maybe a village could have a kit, flying around the sky all day, delivering more than enough power for everything they need. Take a look at the map below. Blue means a large Wind Energy Flux. Meaning lots and lots of wind everyday:

Source: http://www.geni.org/globalenergy/library/renewable-energy-resources/world/sources_world/World_Wind_Lg_Map_files/World.Wind.Lg.jpg One question that I have: Suppose you could build and deliver such a kite-robot to a farm in a windy rural area. What problems would you run into? Now a different alternative energy source idea: We know that more than half of the population lives in cities, and cities are growing at a terryfying pace. To illustrate, take a look at the map below:

Source and type in the link to see the larger picture: http://www.urenio.org/wp-content/uploads/2012/02/citygrowthpopulationwasteproductiongdp.jpg This leads to two problems: What to do with all the waste and wastewater that these cities produce? And how to supply clean but cheap power? I came across the following TED talk by Jonathan Trent, who proposes to use microalgae in bay areas to process wastewater and produce fuel and clean water: I am intriqued by the idea of microalgae for two reasons: 1. Maybe microalgae can be used under different circumstances in more rural areas. (Perhaps in waterbed plastic between the rice plants in the paddy fields when the plants are still growing and have to be seperated from each other anyway? http://www.youtube.com/watch?v=tbUVNBSwyLQ) 2. Waste water is a big problem in a lot of fastgrowing cities. If you look at the map, these cities are often located right at the shore. Just a graphical illustration:

Source: http://beforeitsnews.com/spies-and-intelligence/2011/12/price-inflation-and-a-global-slowdown-ahead-beginning-with-china-pollution-1485733.html

Some questions that came to my mind:
1. How to assess the viability of a new concept? Old fuel forms such as oil are also cheaper because of sunk costs and how to incorporate the added benefits?
2. This microalgae concept has be implemented as a centralized effort. Could you think of alternate ways of using microalgae as biofuels, but in a more decentralized (phone-lady) concept?