There are numereous hurdles to get through before we start seeing microgrid electricity economies.

The first which has already been dealt with by http://www.homerenergy.com is a microgrid simulator that simulates and suggests solutions to the first problem of determining number and type of alternative energy resources are needed for an area.

Then we need to be able to optimize the use of the resources.  This could be framed as an integer optimization problem, however the system is highly dynamic.  Accordingly, a more suitable although not optimal solution would be to use multiagent learning.

If multiagent systems or integer programming can produce a stable result, then the main problem is actually getting the macrogrid companies to start to create them.

http://www.renewableenergyworld.com/rea/news/article/2014/09/microgrid-economics-it-takes-a-village-a-university-and-a-ship above adapted from the link.