that particular problem doesn't seem very hard to me. how do you put electricity in any house? you lay a cable and attach an outlet to it. what does the wall have to do with it? i'd need to read up and learn more details to understand how this is really a serious problem that can't be worked around.
seems to me the major problem is scale and distribution and cost, getting electricity to remote areas. and sure, maybe there are some technical solutions that can help make things easier and cheaper, but i don't see any problems that could not be overcome.
but i have only spent a short time in africa so my understanding of the reality there is quite limited. i'd really like to know more about what the actual roadblocks are and where technological innovations are required to move forward.