What are some of the barriers to accessing affordable energy services among informal settlements?

These are all good points that have been presented in the post above. Circumstance makes the question put forth difficult to hone in on holistically but we all share sensibilities that are reactionary of human instinct based on those circumstances.
Perception of the transient nature of all of our lives makes us want to cherish the comfort of any finites we can find in carrying out our lives. Because our carbon footprints are so multi-sided it becomes a psychological challenge to first acknowledge our impacts on the world, look for new ways of modifying how we live, then aligning our circumstances with any given resources or situations which may prove meriting in breaching less efficient means and methods of carrying out our lives. I'd say the age of the "application platform" has dawned upon a large percentage of the world with access to electronics. Although there is still a large disparity between the connected and the disconnected, the ideology behind scripting, app creation and do-it-yourself problem solving will most likely help to bridge the top-down or bottom-up perception of creating useful change. What I hope to see is an intense hybridization of never-before-seen partnerships between age-old passive technology integrated with low-cost micro "app-like" active systems that will help us all realize in relativity and context, we all share the planet. But who knows, I'm an optimist.