1,6 Billion people do have no Electricity, mainly in Afrika and India
38 Billion Dollar is spend for petrol only for to have light!
Solar-Systems have very much charm. They are build up in few days and supply electrical Power for many years. They are maintenance-free, which is very important for the countries of the south. Only the battery must be changed all 5 to 15 years (depending of the quality). In addition they do not have the environmental pollution (exhaust gases) or noises of a generator and do not have the regularly costs of gasoline, oil etc. The initial costs are higher, but on the long term it is interesting.
Here some Hints on Planing and Engineering